fix length of IDAT chunk

README.md

@@ -10,13 +10,6 @@ Based on the series <a href="https://raytracing.github.io"><cite>Ray Tracing in
 ```
 java -jar raytracing.jar --samples 5000 --height 1080 SIMPLE
 ```
-
-### spheres
-![](./docs/spheres.png)
-
-```
-java -jar raytracing.jar --samples 1000 --height 1080 SPHERES
-```
 ### squares
 ![](./docs/squares.png)
 
@@ -26,7 +19,7 @@ java -jar raytracing.jar --samples 500 --height 1200 SQUARES
 
 ### cornell box
 
-![](./docs/cornell.png)
+![](./docs/cornell_smoke.png)
 
 ```
 java -jar raytracing.jar --samples 50000 --height 1200 CORNELL
@@ -46,12 +39,4 @@ java -jar raytracing.jar --samples 50000 --height 600 CORNELL_SMOKE
 
 ```
 java -jar raytracing.jar --samples 1000 --height 1080 DIAGRAMM
-```
-
-### a little bit of everything
-
-![](./docs/final.png)
-
-```
-java -jar raytracing.jar --samples 10000 --height 1200 FINAL
 ```

src/main/java/eu/jonahbauer/raytracing/Examples.java

@@ -1,21 +1,16 @@
 package eu.jonahbauer.raytracing;
 
-import eu.jonahbauer.raytracing.math.AABB;
 import eu.jonahbauer.raytracing.math.Vec3;
-import eu.jonahbauer.raytracing.render.texture.CheckerTexture;
+import eu.jonahbauer.raytracing.render.Color;
-import eu.jonahbauer.raytracing.render.texture.Color;
 import eu.jonahbauer.raytracing.render.camera.SimpleCamera;
 import eu.jonahbauer.raytracing.render.material.*;
-import eu.jonahbauer.raytracing.render.texture.ImageTexture;
-import eu.jonahbauer.raytracing.render.texture.PerlinTexture;
 import eu.jonahbauer.raytracing.scene.Hittable;
 import eu.jonahbauer.raytracing.scene.Scene;
 import eu.jonahbauer.raytracing.scene.SkyBox;
 import eu.jonahbauer.raytracing.scene.hittable2d.Parallelogram;
-import eu.jonahbauer.raytracing.scene.hittable3d.Box;
 import eu.jonahbauer.raytracing.scene.hittable3d.ConstantMedium;
 import eu.jonahbauer.raytracing.scene.hittable3d.Sphere;
-import eu.jonahbauer.raytracing.scene.util.HittableBinaryTree;
+import eu.jonahbauer.raytracing.scene.util.Hittables;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.*;
@@ -35,11 +30,7 @@ public class Examples {
         register("LIGHT", Examples::getLight);
         register("CORNELL", Examples::getCornellBox);
         register("CORNELL_SMOKE", Examples::getCornellBoxSmoke);
-        register("CORNELL_SPHERE", Examples::getCornellBoxSphere);
         register("DIAGRAMM", Examples::getDiagramm);
-        register("EARTH", Examples::getEarth);
-        register("PERLIN", Examples::getPerlin);
-        register("FINAL", Examples::getFinal);
     }
 
     public static @NotNull IntFunction<Example> getByName(@NotNull String name) {
@@ -51,13 +42,14 @@ public class Examples {
     public static @NotNull Example getSimpleScene(int height) {
         if (height <= 0) height = 675;
         return new Example(
-                new Scene(getSkyBox(), List.of(
+                new Scene(
+                        getSkyBox(),
                         new Sphere(new Vec3(0, -100.5, -1.0), 100.0, new LambertianMaterial(new Color(0.8, 0.8, 0.0))),
                         new Sphere(new Vec3(0, 0, -1.2), 0.5, new LambertianMaterial(new Color(0.1, 0.2, 0.5))),
                         new Sphere(new Vec3(-1.0, 0, -1.2), 0.5, new DielectricMaterial(1.5)),
                         new Sphere(new Vec3(-1.0, 0, -1.2), 0.4, new DielectricMaterial(1 / 1.5)),
                         new Sphere(new Vec3(1.0, 0, -1.2), 0.5, new MetallicMaterial(new Color(0.8, 0.6, 0.2), 0.0))
-                )),
+                ),
                 SimpleCamera.builder()
                         .withImage(height * 16 / 9, height)
                         .build()
@@ -69,10 +61,7 @@ public class Examples {
 
         var rng = new Random(1);
         var objects = new ArrayList<Hittable>();
-        objects.add(new Sphere(
+        objects.add(new Sphere(new Vec3(0, -1000, 0), 1000, new LambertianMaterial(new Color(0.5, 0.5, 0.5))));
-                new Vec3(0, -1000, 0), 1000,
-                new LambertianMaterial(new CheckerTexture(0.32, new Color(.2, .3, .1), new Color(.9, .9, .9)))
-        ));
 
         for (int a = -11; a < 11; a++) {
             for (int b = -11; b < 11; b++) {
@@ -118,13 +107,14 @@ public class Examples {
     public static @NotNull Example getSquares(int height) {
         if (height <= 0) height = 600;
         return new Example(
-                new Scene(getSkyBox(), List.of(
+                new Scene(
+                        getSkyBox(),
                         new Parallelogram(new Vec3(-3, -2, 5), new Vec3(0, 0, -4), new Vec3(0, 4, 0), new LambertianMaterial(new Color(1.0, 0.2, 0.2))),
                         new Parallelogram(new Vec3(-2, -2, 0), new Vec3(4, 0, 0), new Vec3(0, 4, 0), new LambertianMaterial(new Color(0.2, 1.0, 0.2))),
                         new Parallelogram(new Vec3(3, -2, 1), new Vec3(0, 0, 4), new Vec3(0, 4, 0), new LambertianMaterial(new Color(0.2, 0.2, 1.0))),
                         new Parallelogram(new Vec3(-2, 3, 1), new Vec3(4, 0, 0), new Vec3(0, 0, 4), new LambertianMaterial(new Color(1.0, 0.5, 0.0))),
                         new Parallelogram(new Vec3(-2, -3, 5), new Vec3(4, 0, 0), new Vec3(0, 0, -4), new LambertianMaterial(new Color(0.2, 0.8, 0.8)))
-                )),
+                ),
                 SimpleCamera.builder()
                         .withImage(height, height)
                         .withFieldOfView(Math.toRadians(80))
@@ -137,12 +127,12 @@ public class Examples {
     public static @NotNull Example getLight(int height) {
         if (height <= 0) height = 225;
         return new Example(
-                new Scene(List.of(
+                new Scene(
                         new Sphere(new Vec3(0, -1000, 0), 1000, new LambertianMaterial(new Color(0.2, 0.2, 0.2))),
                         new Sphere(new Vec3(0, 2, 0), 2, new LambertianMaterial(new Color(0.2, 0.2, 0.2))),
                         new Parallelogram(new Vec3(3, 1, -2), new Vec3(2, 0, 0), new Vec3(0, 2, 0), new DiffuseLight(new Color(4.0, 4.0, 4.0))),
                         new Sphere(new Vec3(0, 7, 0), 2, new DiffuseLight(new Color(4.0, 4.0, 4.0)))
-                )),
+                ),
                 SimpleCamera.builder()
                         .withImage(height * 16 / 9, height)
                         .withFieldOfView(Math.toRadians(20))
@@ -161,16 +151,16 @@ public class Examples {
         var light = new DiffuseLight(new Color(15.0, 15.0, 15.0));
 
         return new Example(
-                new Scene(List.of(
+                new Scene(
-                        new Box(new Vec3(0, 0, 0), new Vec3(555, 555, 555), white, white, red, green, white, null),
+                        new Parallelogram(new Vec3(555, 0, 0), new Vec3(0, 555, 0), new Vec3(0, 0, 555), green),
+                        new Parallelogram(new Vec3(0, 0, 0), new Vec3(0, 555, 0), new Vec3(0, 0, 555), red),
                         new Parallelogram(new Vec3(343, 554, 332), new Vec3(-130, 0, 0), new Vec3(0, 0, -105), light),
-                        new Box(new Vec3(0, 0, 0), new Vec3(165, 330, 165), white)
+                        new Parallelogram(new Vec3(0, 0, 0), new Vec3(555, 0, 0), new Vec3(0, 0, 555), white),
-                                .rotateY(Math.toRadians(15))
+                        new Parallelogram(new Vec3(555, 555, 555), new Vec3(-555, 0, 0), new Vec3(0, 0, -555), white),
-                                .translate(new Vec3(265, 0, 295)),
+                        new Parallelogram(new Vec3(0, 0, 555), new Vec3(555, 0, 0), new Vec3(0, 555, 0), white),
-                        new Box(new Vec3(0, 0, 0), new Vec3(165, 165, 165), white)
+                        Hittables.box(new Vec3(0, 0, 0), new Vec3(165, 330, 165), white).rotateY(Math.toRadians(15)).translate(new Vec3(265, 0, 295)),
-                                .rotateY(Math.toRadians(-18))
+                        Hittables.box(new Vec3(0, 0, 0), new Vec3(165, 165, 165), white).rotateY(Math.toRadians(-18)).translate(new Vec3(130, 0, 65))
-                                .translate(new Vec3(130, 0, 65))
+                ),
-                )),
                 SimpleCamera.builder()
                         .withImage(height, height)
                         .withFieldOfView(Math.toRadians(40))
@@ -188,49 +178,22 @@ public class Examples {
         var light = new DiffuseLight(new Color(7.0, 7.0, 7.0));
 
         return new Example(
-                new Scene(List.of(
+                new Scene(
-                        new Box(new Vec3(0, 0, 0), new Vec3(555, 555, 555), white, white, red, green, white, null),
+                        new Parallelogram(new Vec3(555, 0, 0), new Vec3(0, 555, 0), new Vec3(0, 0, 555), green),
+                        new Parallelogram(new Vec3(0, 0, 0), new Vec3(0, 555, 0), new Vec3(0, 0, 555), red),
                         new Parallelogram(new Vec3(113, 554, 127), new Vec3(330, 0, 0), new Vec3(0, 0, 305), light),
+                        new Parallelogram(new Vec3(0, 0, 0), new Vec3(555, 0, 0), new Vec3(0, 0, 555), white),
+                        new Parallelogram(new Vec3(555, 555, 555), new Vec3(-555, 0, 0), new Vec3(0, 0, -555), white),
+                        new Parallelogram(new Vec3(0, 0, 555), new Vec3(555, 0, 0), new Vec3(0, 555, 0), white),
                         new ConstantMedium(
-                                new Box(new Vec3(0, 0, 0), new Vec3(165, 330, 165), white)
+                                Hittables.box(new Vec3(0, 0, 0), new Vec3(165, 330, 165), white).rotateY(Math.toRadians(15)).translate(new Vec3(265, 0, 295)),
-                                        .rotateY(Math.toRadians(15))
-                                        .translate(new Vec3(265, 0, 295)),
                                 0.01, new IsotropicMaterial(Color.BLACK)
                         ),
                         new ConstantMedium(
-                                new Box(new Vec3(0, 0, 0), new Vec3(165, 165, 165), white)
+                                Hittables.box(new Vec3(0, 0, 0), new Vec3(165, 165, 165), white).rotateY(Math.toRadians(-18)).translate(new Vec3(130, 0, 65)),
-                                        .rotateY(Math.toRadians(-18))
-                                        .translate(new Vec3(130, 0, 65)),
                                 0.01, new IsotropicMaterial(Color.WHITE)
                         )
-                )),
+                ),
-                SimpleCamera.builder()
-                        .withImage(height, height)
-                        .withFieldOfView(Math.toRadians(40))
-                        .withPosition(new Vec3(278, 278, -800))
-                        .withTarget(new Vec3(278, 278, 0))
-                        .build()
-        );
-    }
-
-    public static @NotNull Example getCornellBoxSphere(int height) {
-        if (height <= 0) height = 600;
-
-        var red = new LambertianMaterial(new Color(.65, .05, .05));
-        var white = new LambertianMaterial(new Color(.73, .73, .73));
-        var green = new LambertianMaterial(new Color(.12, .45, .15));
-        var light = new DiffuseLight(new Color(7.0, 7.0, 7.0));
-        var glass = new DielectricMaterial(1.5);
-
-        var room = new Box(new Vec3(0, 0, 0), new Vec3(555, 555, 555), white, white, red, green, white, null);
-        var lamp = new Parallelogram(new Vec3(343, 554, 332), new Vec3(-130, 0, 0), new Vec3(0, 0, -105), light);
-        var box = new Box(new Vec3(0, 0, 0), new Vec3(165, 330, 165), white)
-                .rotateY(Math.toRadians(15))
-                .translate(new Vec3(265, 0, 295));
-        var sphere = new Sphere(new Vec3(190, 90, 190), 90, glass);
-
-        return new Example(
-                new Scene(List.of(room, box), List.of(lamp, sphere)),
                 SimpleCamera.builder()
                         .withImage(height, height)
                         .withFieldOfView(Math.toRadians(40))
@@ -270,7 +233,7 @@ public class Examples {
 
         for (int i = 0; i < data.size(); i++) {
             var partei = data.get(i);
-            objects.add(new Box(
+            objects.add(Hittables.box(
                     new Vec3((i + 1) * spacing +       i * size, 0, spacing),
                     new Vec3((i + 1) * spacing + (i + 1) * size, partei.stimmen() * 15, spacing + size),
                     new DielectricMaterial(1.5, partei.color())
@@ -288,109 +251,6 @@ public class Examples {
         );
     }
 
-    public static @NotNull Example getEarth(int height) {
-        if (height <= 0) height = 450;
-
-        return new Example(
-                new Scene(getSkyBox(), List.of(
-                        new Sphere(Vec3.ZERO, 2, new LambertianMaterial(new ImageTexture("/earthmap.jpg")))
-                )),
-                SimpleCamera.builder()
-                        .withImage(height * 16 / 9, height)
-                        .withFieldOfView(Math.toRadians(20))
-                        .withPosition(new Vec3(12, 0, 0))
-                        .withTarget(Vec3.ZERO)
-                        .build()
-        );
-    }
-
-    public static @NotNull Example getPerlin(int height) {
-        if (height <= 0) height = 450;
-
-        var material = new LambertianMaterial(new PerlinTexture(4));
-
-        return new Example(
-                new Scene(getSkyBox(), List.of(
-                        new Sphere(new Vec3(0, -1000, 0), 1000, material),
-                        new Sphere(new Vec3(0, 2, 0), 2, material)
-                )),
-                SimpleCamera.builder()
-                        .withImage(height * 16 / 9, height)
-                        .withFieldOfView(Math.toRadians(20))
-                        .withPosition(new Vec3(13, 2, 3))
-                        .withTarget(Vec3.ZERO)
-                        .build()
-        );
-    }
-
-    public static @NotNull Example getFinal(int height) {
-        if (height <= 0) height = 400;
-
-        var objects = new ArrayList<Hittable>();
-        var random = new Random(1);
-
-        // boxes
-        var boxes = new ArrayList<Hittable>();
-        var ground = new LambertianMaterial(new Color(0.48, 0.83, 0.53));
-        for (int i = 0; i < 20; i++) {
-            for (int j = 0; j < 20; j++) {
-                var w = 100.0;
-                var x0 = -1000.0 + i * w;
-                var z0 = -1000.0 + j * w;
-                var y0 = 0.0;
-                var x1 = x0 + w;
-                var y1 = random.nextInt(1, 101);
-                var z1 = z0 + w;
-                boxes.add(new Box(new Vec3(x0, y0, z0), new Vec3(x1, y1, z1), ground));
-            }
-        }
-        objects.add(new HittableBinaryTree(boxes));
-
-        // light
-        objects.add(new Parallelogram(
-                new Vec3(123, 554, 147), new Vec3(300, 0, 0), new Vec3(0, 0, 265),
-                new DiffuseLight(new Color(7., 7., 7.))
-        ));
-
-        // spheres with different materials
-        objects.add(new Sphere(new Vec3(400, 400, 200), 50, new LambertianMaterial(new Color(0.7, 0.3, 0.1))));
-        objects.add(new Sphere(new Vec3(260, 150, 45), 50, new DielectricMaterial(1.5)));
-        objects.add(new Sphere(new Vec3(0, 150, 145), 50, new MetallicMaterial(new Color(0.8, 0.8, 0.9), 1.0)));
-
-        // glass sphere filled with gas
-        var boundary = new Sphere(new Vec3(360, 150, 145), 70, new DielectricMaterial(1.5));
-        objects.add(boundary);
-        objects.add(new ConstantMedium(boundary, 0.2, new IsotropicMaterial(new Color(0.2, 0.4, 0.9))));
-
-        // put the world in a glass sphere
-        objects.add(new ConstantMedium(
-                new Sphere(new Vec3(0, 0, 0), 5000, new DielectricMaterial(1.5)),
-                0.0001, new IsotropicMaterial(new Color(1., 1., 1.))
-        ));
-
-        // textures spheres
-        objects.add(new Sphere(new Vec3(400, 200, 400), 100, new LambertianMaterial(new ImageTexture("/earthmap.jpg"))));
-        objects.add(new Sphere(new Vec3(220, 280, 300), 80, new LambertianMaterial(new PerlinTexture(0.2))));
-
-        // box from spheres
-        var white = new LambertianMaterial(new Color(.73, .73, .73));
-        var spheres = new ArrayList<Hittable>();
-        for (int j = 0; j < 1000; j++) {
-            spheres.add(new Sphere(new Vec3(random.nextDouble(165), random.nextDouble(165), random.nextDouble(165)), 10, white));
-        }
-        objects.add(new HittableBinaryTree(spheres).rotateY(Math.toRadians(15)).translate(new Vec3(-100, 270, 395)));
-
-        return new Example(
-                new Scene(objects),
-                SimpleCamera.builder()
-                        .withImage(height, height)
-                        .withFieldOfView(Math.toRadians(40))
-                        .withPosition(new Vec3(478, 278, -600))
-                        .withTarget(new Vec3(278, 278, 0))
-                        .build()
-        );
-    }
-
     private static @NotNull SkyBox getSkyBox() {
         return SkyBox.gradient(new Color(0.5, 0.7, 1.0), Color.WHITE);
     }

src/main/java/eu/jonahbauer/raytracing/Main.java

@@ -13,8 +13,6 @@ import java.nio.file.Path;
 import java.util.function.IntFunction;
 
 public class Main {
-    public static final boolean DEBUG = false;
-
     public static void main(String[] args) throws IOException {
         var config = Config.parse(args);
         var example = config.example;

src/main/java/eu/jonahbauer/raytracing/math/AABB.java

@@ -11,6 +11,7 @@ import java.util.Optional;
  * An axis-aligned bounding box.
  */
 public record AABB(@NotNull Vec3 min, @NotNull Vec3 max) {
+    public static final AABB UNIVERSE = new AABB(Vec3.MIN, Vec3.MAX);
     public static final AABB EMPTY = new AABB(Vec3.ZERO, Vec3.ZERO);
     public static final Comparator<AABB> X_AXIS = Comparator.comparing(AABB::min, Comparator.comparingDouble(Vec3::x));
     public static final Comparator<AABB> Y_AXIS = Comparator.comparing(AABB::min, Comparator.comparingDouble(Vec3::y));
@@ -35,53 +36,38 @@ public record AABB(@NotNull Vec3 min, @NotNull Vec3 max) {
         return Optional.ofNullable(bbox);
     }
 
-    /**
-     * {@return the range of x values}
-     */
     public @NotNull Range x() {
         return new Range(min.x(), max.x());
     }
 
-    /**
-     * {@return the range of y values}
-     */
     public @NotNull Range y() {
         return new Range(min.y(), max.y());
     }
 
-    /**
-     * {@return the range of z values}
-     */
     public @NotNull Range z() {
         return new Range(min.z(), max.z());
     }
 
-    /**
-     * {@return the center of this bounding box}
-     */
     public @NotNull Vec3 center() {
         return Vec3.average(min, max, 2);
     }
 
-    /**
-     * Expands this bounding box to include the other bounding box.
-     * @param box a bounding box
-     * @return the expanded bounding box
-     */
     public @NotNull AABB expand(@NotNull AABB box) {
         return new AABB(Vec3.min(this.min, box.min), Vec3.max(this.max, box.max));
     }
 
-    /**
+    public boolean hit(@NotNull Ray ray) {
-     * Tests whether the {@code ray} intersects this bounding box withing the {@code range}
+        return intersect(ray).isPresent();
-     * @param ray a ray
+    }
-     * @param range a range of valid {@code t}s
+
-     * @return {@code true} iff the ray intersects this bounding box, {@code false} otherwise
+    public @NotNull Optional<Range> intersect(@NotNull Ray ray) {
-     */
+        if (this == UNIVERSE) return Optional.of(Range.UNIVERSE);
-    public boolean hit(@NotNull Ray ray, @NotNull Range range) {
+        if (this == EMPTY) return Optional.empty();
+
+        int vmask = ray.vmask();
+
         var origin = ray.origin();
-        var direction = ray.direction();
+        var invDirection = ray.direction().inv();
-        var invDirection = direction.inv();
 
         // calculate t values for intersection points of ray with planes through min
         var tmin = intersect(min(), origin, invDirection);
@@ -91,31 +77,27 @@ public record AABB(@NotNull Vec3 min, @NotNull Vec3 max) {
         // determine range of t for which the ray is inside this voxel
         double tlmax = Double.NEGATIVE_INFINITY; // lower limit maximum
         double tumin = Double.POSITIVE_INFINITY; // upper limit minimum
-
         for (int i = 0; i < 3; i++) {
-            // classify t values as lower or upper limit based on ray direction
+            // classify t values as lower or upper limit based on vmask
-            if (direction.get(i) >= 0) {
+            if ((vmask & (1 << i)) == 0) {
                 // min is lower limit and max is upper limit
-                if (tmin[i] > tlmax) tlmax = tmin[i];
+                tlmax = Math.max(tlmax, tmin[i]);
-                if (tmax[i] < tumin) tumin = tmax[i];
+                tumin = Math.min(tumin, tmax[i]);
             } else {
                 // max is lower limit and min is upper limit
-                if (tmax[i] > tlmax) tlmax = tmax[i];
+                tlmax = Math.max(tlmax, tmax[i]);
-                if (tmin[i] < tumin) tumin = tmin[i];
+                tumin = Math.min(tumin, tmin[i]);
             }
         }
 
-        return tlmax < tumin && tumin >= range.min() && tlmax <= range.max();
+        return tlmax < tumin ? Optional.of(new Range(tlmax, tumin)) : Optional.empty();
     }
 
-    /**
+    public static double @NotNull[] intersect(@NotNull Vec3 corner, @NotNull Ray ray) {
-     * Computes the {@code t} values of the intersections of a ray with the axis-aligned planes through a point.
+        return intersect(corner, ray.origin(), ray.direction().inv());
-     * @param corner the point
+    }
-     * @param origin the origin point of the ray
+
-     * @param invDirection the {@linkplain Vec3#inv() inverted} direction of the ray
+    private static double @NotNull[] intersect(@NotNull Vec3 corner, @NotNull Vec3 origin, @NotNull Vec3 invDirection) {
-     * @return a three-element array of the {@code t} values of the intersection with the yz-, xz- and xy-plane through {@code corner}
-     */
-    public static double @NotNull[] intersect(@NotNull Vec3 corner, @NotNull Vec3 origin, @NotNull Vec3 invDirection) {
         return new double[] {
                 (corner.x() - origin.x()) * invDirection.x(),
                 (corner.y() - origin.y()) * invDirection.y(),

src/main/java/eu/jonahbauer/raytracing/math/Ray.java

@@ -11,6 +11,16 @@ public record Ray(@NotNull Vec3 origin, @NotNull Vec3 direction) {
     }
 
     public @NotNull Vec3 at(double t) {
-        return Vec3.fma(t, direction, origin);
+        return new Vec3(
+                origin().x() + t * direction.x(),
+                origin().y() + t * direction.y(),
+                origin().z() + t * direction.z()
+        );
+    }
+
+    public int vmask() {
+        return (direction().x() < 0 ? 1 : 0)
+                | (direction().y() < 0 ? 2 : 0)
+                | (direction().z() < 0 ? 4 : 0);
     }
 }

src/main/java/eu/jonahbauer/raytracing/math/Vec3.java

@@ -5,8 +5,6 @@ import org.jetbrains.annotations.NotNull;
 import java.util.Optional;
 import java.util.random.RandomGenerator;
 
-import static eu.jonahbauer.raytracing.Main.DEBUG;
-
 public record Vec3(double x, double y, double z) {
     public static final Vec3 ZERO = new Vec3(0, 0, 0);
     public static final Vec3 MAX = new Vec3(Double.MAX_VALUE, Double.MAX_VALUE, Double.MAX_VALUE);
@@ -16,63 +14,26 @@ public record Vec3(double x, double y, double z) {
     public static final Vec3 UNIT_Z = new Vec3(0, 0, 1);
 
     public Vec3 {
-        if (DEBUG) {
+        assert Double.isFinite(x) && Double.isFinite(y) && Double.isFinite(z) : "x, y and z must be finite";
-            if (!Double.isFinite(x) || !Double.isFinite(y) || !Double.isFinite(z)) {
-                throw new IllegalArgumentException("x, y and z must be finite");
-            }
-        }
     }
 
-    /**
-     * {@return a uniformly random unit vector}
-     */
     public static @NotNull Vec3 random(@NotNull RandomGenerator random) {
-        double x, y, z;
+        return random(random, false);
-        double squared;
-        do {
-            x = Math.fma(2, random.nextDouble(), -1);
-            y = Math.fma(2, random.nextDouble(), -1);
-            z = Math.fma(2, random.nextDouble(), -1);
-            squared = x * x + y * y + z * z;
-        } while (squared > 1);
-        var factor = 1 / Math.sqrt(squared);
-        return new Vec3(x * factor, y * factor, z * factor);
     }
 
-    /**
+    public static @NotNull Vec3 random(@NotNull RandomGenerator random, boolean unit) {
-     * {@return a uniformly random unit vector on the opposite hemisphere of the given <code>direction</code>}
+        var vec = new Vec3(
-     */
+                2 * random.nextDouble() - 1,
-    public static @NotNull Vec3 randomOppositeHemisphere(@NotNull RandomGenerator random, @NotNull Vec3 direction) {
+                2 * random.nextDouble() - 1,
-        double x, y, z;
+                2 * random.nextDouble() - 1
-        double squared;
+        );
-        do {
+        return unit ? vec.unit() : vec;
-            x = Math.fma(2, random.nextDouble(), -1);
-            y = Math.fma(2, random.nextDouble(), -1);
-            z = Math.fma(2, random.nextDouble(), -1);
-            squared = x * x + y * y + z * z;
-        } while (squared > 1 || direction.x() * x + direction.y() * y + direction.z() * z >= 0);
-        var factor = 1 / Math.sqrt(squared);
-        return new Vec3(x * factor, y * factor, z * factor);
     }
 
-    /**
-     * Reflects a vector on the given {@code normal} vector.
-     * @param vec a vector
-     * @param normal the surface normal (must be a unit vector)
-     * @return the reflected vector
-     */
     public static @NotNull Vec3 reflect(@NotNull Vec3 vec, @NotNull Vec3 normal) {
-        var factor = - 2 * normal.times(vec);
+        return vec.minus(normal.times(2 * normal.times(vec)));
-        return Vec3.fma(factor, normal, vec);
     }
 
-    /**
-     * Refracts a vector on the given {@code normal} vector.
-     * @param vec a vector
-     * @param normal the surface normal (must be a unit vector)
-     * @param ri the refractive index
-     * @return the refracted vector
-     */
     public static @NotNull Optional<Vec3> refract(@NotNull Vec3 vec, @NotNull Vec3 normal, double ri) {
         vec = vec.unit();
         var cosTheta = Math.min(- vec.times(normal), 1.0);
@@ -84,49 +45,24 @@ public record Vec3(double x, double y, double z) {
         return Optional.of(rOutPerp.plus(rOutParallel));
     }
 
-    /**
-     * Rotates a vector around an {@code axis}.
-     * @param vec a vector
-     * @param axis the rotation axis
-     * @param angle the angle in radians
-     * @return the rotated vector
-     */
     public static @NotNull Vec3 rotate(@NotNull Vec3 vec, @NotNull Vec3 axis, double angle) {
         Vec3 vxp = axis.cross(vec);
         Vec3 vxvxp = axis.cross(vxp);
         return vec.plus(vxp.times(Math.sin(angle))).plus(vxvxp.times(1 - Math.cos(angle)));
     }
 
-    /**
-     * {@return the euclidean distance between two vectors}
-     * @param a a vector
-     * @param b another vector
-     */
     public static double distance(@NotNull Vec3 a, @NotNull Vec3 b) {
         return a.minus(b).length();
     }
 
-    /**
-     * Computes a running average of vectors.
-     * @param current the current running average
-     * @param next the next vector
-     * @param index the one-based index of the next vector
-     * @return the new running average
-     */
     public static @NotNull Vec3 average(@NotNull Vec3 current, @NotNull Vec3 next, int index) {
-        var factor = 1d / index;
         return new Vec3(
-                Math.fma(factor, next.x() - current.x(), current.x()),
+                current.x() + (next.x() - current.x()) / index,
-                Math.fma(factor, next.y() - current.y(), current.y()),
+                current.y() + (next.y() - current.y()) / index,
-                Math.fma(factor, next.z() - current.z(), current.z())
+                current.z() + (next.z() - current.z()) / index
         );
     }
 
-    /**
-     * {@return a component-wise maximum vector}
-     * @param a a vector
-     * @param b another vector
-     */
     public static @NotNull Vec3 max(@NotNull Vec3 a, @NotNull Vec3 b) {
         return new Vec3(
                 Math.max(a.x(), b.x()),
@@ -135,11 +71,6 @@ public record Vec3(double x, double y, double z) {
         );
     }
 
-    /**
-     * {@return a component-wise minimum vector}
-     * @param a a vector
-     * @param b another vector
-     */
     public static @NotNull Vec3 min(@NotNull Vec3 a, @NotNull Vec3 b) {
         return new Vec3(
                 Math.min(a.x(), b.x()),
@@ -148,24 +79,6 @@ public record Vec3(double x, double y, double z) {
         );
     }
 
-    /**
-     * {@return <code>a * b + c</code>}
-     * @param a scalar
-     * @param b a vector
-     * @param c another vector
-     */
-    public static @NotNull Vec3 fma(double a, @NotNull Vec3 b, @NotNull Vec3 c) {
-        return new Vec3(
-                Math.fma(a, b.x(), c.x()),
-                Math.fma(a, b.y(), c.y()),
-                Math.fma(a, b.z(), c.z())
-        );
-    }
-
-    public static double tripleProduct(@NotNull Vec3 a, @NotNull Vec3 b, @NotNull Vec3 c) {
-        return a.x * b.y * c.z + a.y * b.z * c.x + a.z * b.x * c.y - c.x * b.y * a.z - c.y * b.z * a.x - c.z * b.x * a.y;
-    }
-
     public @NotNull Vec3 plus(double x, double y, double z) {
         return new Vec3(this.x + x, this.y + y, this.z + z);
     }
@@ -174,122 +87,57 @@ public record Vec3(double x, double y, double z) {
         return new Vec3(this.x - x, this.y - y, this.z - z);
     }
 
-    /**
+    public @NotNull Vec3 plus(@NotNull Vec3 b) {
-     * Adds a vector to this vector
+        return new Vec3(this.x + b.x, this.y + b.y, this.z + b.z);
-     * @param other a vector
+    }
-     * @return the sum of this and the other vector
+    
-     */
+    public @NotNull Vec3 minus(@NotNull Vec3 b) {
-    public @NotNull Vec3 plus(@NotNull Vec3 other) {
+        return new Vec3(this.x - b.x, this.y - b.y, this.z - b.z);
-        return new Vec3(this.x + other.x, this.y + other.y, this.z + other.z);
+    }
+    
+    public double times(@NotNull Vec3 b) {
+        return this.x * b.x + this.y * b.y + this.z * b.z;
+    }
+    
+    public @NotNull Vec3 times(double b) {
+        return new Vec3(this.x * b, this.y * b, this.z * b);
     }
 
-    /**
-     * Subtracts a vector from this vector
-     * @param other a vector
-     * @return the difference of this and the other vector
-     */
-    public @NotNull Vec3 minus(@NotNull Vec3 other) {
-        return new Vec3(this.x - other.x, this.y - other.y, this.z - other.z);
-    }
-
-    /**
-     * Computes the scalar product of this and another vector
-     * @param other a vector
-     * @return the scalar product
-     */
-    public double times(@NotNull Vec3 other) {
-        return this.x * other.x + this.y * other.y + this.z * other.z;
-    }
-
-    /**
-     * Multiplies this vector with a scalar
-     * @param t a scalar
-     * @return the product of this vector and the scalar
-     */
-    public @NotNull Vec3 times(double t) {
-        return new Vec3(this.x * t, this.y * t, this.z * t);
-    }
-
-    /**
-     * Negates this vector.
-     * {@return the negated vector}
-     */
     public @NotNull Vec3 neg() {
         return new Vec3(-x, -y, -z);
     }
 
-    /**
-     * Inverts each component of this vector.
-     * @return the inverted vector.
-     */
     public @NotNull Vec3 inv() {
         return new Vec3(1 / x, 1 / y, 1 / z);
     }
 
-    /**
+    public @NotNull Vec3 cross(@NotNull Vec3 b) {
-     * Computes the cross-product of this and another vector
-     * @param other a vector
-     * @return the cross-product
-     */
-    public @NotNull Vec3 cross(@NotNull Vec3 other) {
         return new Vec3(
-                Math.fma(this.y, other.z, - other.y * this.z),
+                this.y() * b.z() - b.y() * this.z(),
-                Math.fma(this.z, other.x, - other.z * this.x),
+                this.z() * b.x() - b.z() * this.x(),
-                Math.fma(this.x, other.y, - other.x * this.y)
+                this.x() * b.y() - b.x() * this.y()
         );
     }
 
-    /**
+    public @NotNull Vec3 div(double b) {
-     * Divides this vector by a scalar
+        return new Vec3(this.x / b, this.y / b, this.z / b);
-     * @param t a scalar
-     * @return this vector divided by the scalar
-     */
-    public @NotNull Vec3 div(double t) {
-        return new Vec3(this.x / t, this.y / t, this.z / t);
     }
 
-    /**
-     * {@return the squared length of this vector}
-     */
     public double squared() {
         return this.x * this.x + this.y * this.y + this.z * this.z;
     }
-
+    
-    /**
-     * {@return the length of this vector}
-     */
     public double length() {
         return Math.sqrt(squared());
     }
 
-    /**
-     * {@return whether this vector is near zero}
-     */
     public boolean isNearZero() {
         var s = 1e-8;
         return Math.abs(x) < s && Math.abs(y) < s && Math.abs(z) < s;
     }
-
+    
-    /**
-     * {@return a unit vector with the same direction as this vector}
-     */
     public @NotNull Vec3 unit() {
-        var squared = squared();
+        return div(length());
-        if (squared == 1) return this;
-        return div(Math.sqrt(squared));
-    }
-
-    /**
-     * {@return the n-th component of this vector}
-     * @param axis the component index
-     */
-    public double get(int axis) {
-        return switch (axis) {
-            case 0 -> x;
-            case 1 -> y;
-            case 2 -> z;
-            default -> throw new IndexOutOfBoundsException(axis);
-        };
     }
 
     public @NotNull Vec3 withX(double x) {
@@ -303,9 +151,4 @@ public record Vec3(double x, double y, double z) {
     public @NotNull Vec3 withZ(double z) {
         return new Vec3(x, y, z);
     }
-
-    @Override
-    public @NotNull String toString() {
-        return "(" + x + "," + y + "," + z + ")";
-    }
 }

src/main/java/eu/jonahbauer/raytracing/render/Color.java

@@ -1,15 +1,10 @@
-package eu.jonahbauer.raytracing.render.texture;
+package eu.jonahbauer.raytracing.render;
 
-import eu.jonahbauer.raytracing.math.Ray;
-import eu.jonahbauer.raytracing.math.Vec3;
-import eu.jonahbauer.raytracing.scene.SkyBox;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.Random;
 
-import static eu.jonahbauer.raytracing.Main.DEBUG;
+public record Color(double r, double g, double b) {
-
-public record Color(double r, double g, double b) implements Texture, SkyBox {
     public static final @NotNull Color BLACK = new Color(0.0, 0.0, 0.0);
     public static final @NotNull Color WHITE = new Color(1.0, 1.0, 1.0);
     public static final @NotNull Color RED = new Color(1.0, 0.0, 0.0);
@@ -30,10 +25,6 @@ public record Color(double r, double g, double b) implements Texture, SkyBox {
         return new Color(a.r() * b.r(), a.g() * b.g(), a.b() * b.b());
     }
 
-    public static @NotNull Color multiply(@NotNull Color a, double b) {
-        return new Color(a.r() * b, a.g() * b, a.b() * b);
-    }
-
     public static @NotNull Color add(@NotNull Color a, @NotNull Color b) {
         return new Color(a.r() + b.r(), a.g() + b.g(), a.b() + b.b());
     }
@@ -52,11 +43,10 @@ public record Color(double r, double g, double b) implements Texture, SkyBox {
     }
 
     public static @NotNull Color average(@NotNull Color current, @NotNull Color next, int index) {
-        var factor = 1d / index;
         return new Color(
-                Math.fma(factor, next.r() - current.r(), current.r()),
+                current.r() + (next.r() - current.r()) / index,
-                Math.fma(factor, next.g() - current.g(), current.g()),
+                current.g() + (next.g() - current.g()) / index,
-                Math.fma(factor, next.b() - current.b(), current.b())
+                current.b() + (next.b() - current.b()) / index
         );
     }
 
@@ -78,25 +68,12 @@ public record Color(double r, double g, double b) implements Texture, SkyBox {
         }
     }
 
-    public Color(int rgb) {
+    public Color {}
-        this((rgb >> 16) & 0xFF, (rgb >> 8) & 0xFF, rgb & 0xFF);
-    }
     
     public Color(int red, int green, int blue) {
         this(red / 255f, green / 255f, blue / 255f);
     }
 
-    public Color {
-        if (DEBUG) {
-            if (!Double.isFinite(r) || !Double.isFinite(g) || !Double.isFinite(b)) {
-                throw new IllegalArgumentException("r, g and b must be finite");
-            }
-            if (r < 0 || g < 0 || b < 0) {
-                throw new IllegalArgumentException("r, g and b must be non-negative");
-            }
-        }
-    }
-
     public int red() {
         return toInt(r);
     }
@@ -109,22 +86,7 @@ public record Color(double r, double g, double b) implements Texture, SkyBox {
         return toInt(b);
     }
 
-    @Override
-    public @NotNull Color get(double u, double v, @NotNull Vec3 p) {
-        return this;
-    }
-
-    @Override
-    public @NotNull Color getColor(@NotNull Ray ray) {
-        return this;
-    }
-
-    @Override
-    public boolean isUVRequired() {
-        return false;
-    }
-
     private static int toInt(double value) {
-        return Math.clamp((int) (255.99 * value), 0, 255);
+        return Math.max(0, Math.min(255, (int) (255.99 * value)));
     }
 }

src/main/java/eu/jonahbauer/raytracing/render/ImageFormat.java

@@ -43,7 +43,7 @@ public enum ImageFormat {
         private static final int IHDR_TYPE = 0x49484452;
         private static final int IDAT_TYPE = 0x49444154;
         private static final int IEND_TYPE = 0x49454E44;
-        private static final int IEND_CRC = 0xAE426082;
+        private static final int IEND_CRC = -1371381630;
 
         @Override
         public void write(@NotNull Canvas image, @NotNull OutputStream out) throws IOException {

src/main/java/eu/jonahbauer/raytracing/render/camera/Camera.java

@@ -18,13 +18,7 @@ public interface Camera {
 
     /**
      * Casts a ray through the given pixel.
-     * @param x the pixel x coordinate
-     * @param y the pixel y coordinate
-     * @param i the subpixel x coordinate
-     * @param j the subpixel y coordinate
-     * @param n the subpixel count (per side)
-     * @param random a random number generator
      * @return a new ray
      */
-    @NotNull Ray cast(int x, int y, int i, int j, int n, @NotNull RandomGenerator random);
+    @NotNull Ray cast(int x, int y, @NotNull RandomGenerator random);
 }

src/main/java/eu/jonahbauer/raytracing/render/camera/SimpleCamera.java

@@ -60,7 +60,7 @@ public final class SimpleCamera implements Camera {
 
         this.pixel00 = origin.plus(direction.times(builder.focusDistance))
                 .minus(u.times(0.5 * viewportWidth)).minus(v.times(0.5 * viewportHeight))
-                .plus(pixelU.times(.5)).plus(pixelV.times(.5));
+                .plus(pixelU.div(2)).plus(pixelV.div(2));
     }
 
     /**
@@ -79,20 +79,13 @@ public final class SimpleCamera implements Camera {
 
     /**
      * {@inheritDoc}
-     * @param x {@inheritDoc}
-     * @param y {@inheritDoc}
-     * @param i {@inheritDoc}
-     * @param j {@inheritDoc}
-     * @param n {@inheritDoc}
-     * @param random {@inheritDoc}
      */
-    @Override
+    public @NotNull Ray cast(int x, int y, @NotNull RandomGenerator random) {
-    public @NotNull Ray cast(int x, int y, int i, int j, int n, @NotNull RandomGenerator random) {
         Objects.checkIndex(x, width);
         Objects.checkIndex(y, height);
 
         var origin = getRayOrigin(random);
-        var target = getRayTarget(x, y, i, j, n, random);
+        var target = getRayTarget(x, y, random);
         return new Ray(origin, target.minus(origin));
     }
 
@@ -105,8 +98,8 @@ public final class SimpleCamera implements Camera {
         if (blurRadius <= 0) return origin;
 
         while (true) {
-            var du = Math.fma(2, random.nextDouble(), -1);
+            var du = 2 * random.nextDouble() - 1;
-            var dv = Math.fma(2, random.nextDouble(), -1);
+            var dv = 2 * random.nextDouble() - 1;
             if (du * du + dv * dv >= 1) continue;
 
             var ru = blurRadius * du;
@@ -123,10 +116,9 @@ public final class SimpleCamera implements Camera {
     /**
      * {@return the target vector for a ray through the given pixel} The position is randomized within the pixel.
      */
-    private @NotNull Vec3 getRayTarget(int x, int y, int i, int j, int n, @NotNull RandomGenerator random) {
+    private @NotNull Vec3 getRayTarget(int x, int y, @NotNull RandomGenerator random) {
-        var factor = 1d / n;
+        double dx = x + random.nextDouble() - 0.5;
-        var dx = x + Math.fma(factor, i + random.nextDouble(), -0.5);
+        double dy = y + random.nextDouble() - 0.5;
-        var dy = y + Math.fma(factor, j + random.nextDouble(), -0.5);
         return pixel00.plus(pixelU.times(dx)).plus(pixelV.times(dy));
     }
 

src/main/java/eu/jonahbauer/raytracing/render/canvas/Canvas.java

@@ -1,6 +1,6 @@
 package eu.jonahbauer.raytracing.render.canvas;
 
-import eu.jonahbauer.raytracing.render.texture.Color;
+import eu.jonahbauer.raytracing.render.Color;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.function.Function;

src/main/java/eu/jonahbauer/raytracing/render/canvas/Image.java

@@ -1,9 +1,8 @@
 package eu.jonahbauer.raytracing.render.canvas;
 
-import eu.jonahbauer.raytracing.render.texture.Color;
+import eu.jonahbauer.raytracing.render.Color;
 import org.jetbrains.annotations.NotNull;
 
-import java.awt.image.BufferedImage;
 import java.util.Objects;
 
 public final class Image implements Canvas {
@@ -22,16 +21,6 @@ public final class Image implements Canvas {
         this.data = new Color[height][width];
     }
 
-    public Image(@NotNull BufferedImage image) {
-        this(image.getWidth(), image.getHeight());
-
-        for (int y = 0; y < height; y++) {
-            for (int x = 0; x < width; x++) {
-                this.data[y][x] = new Color(image.getRGB(x, y));
-            }
-        }
-    }
-
     @Override
     public int getWidth() {
         return width;

src/main/java/eu/jonahbauer/raytracing/render/canvas/LiveCanvas.java

@@ -1,6 +1,6 @@
 package eu.jonahbauer.raytracing.render.canvas;
 
-import eu.jonahbauer.raytracing.render.texture.Color;
+import eu.jonahbauer.raytracing.render.Color;
 import org.jetbrains.annotations.NotNull;
 
 import javax.swing.*;

src/main/java/eu/jonahbauer/raytracing/render/material/DielectricMaterial.java

@@ -2,8 +2,7 @@ package eu.jonahbauer.raytracing.render.material;
 
 import eu.jonahbauer.raytracing.math.Ray;
 import eu.jonahbauer.raytracing.math.Vec3;
-import eu.jonahbauer.raytracing.render.texture.Color;
+import eu.jonahbauer.raytracing.render.Color;
-import eu.jonahbauer.raytracing.render.texture.Texture;
 import eu.jonahbauer.raytracing.scene.HitResult;
 import org.jetbrains.annotations.NotNull;
 
@@ -11,18 +10,18 @@ import java.util.Objects;
 import java.util.Optional;
 import java.util.random.RandomGenerator;
 
-public record DielectricMaterial(double refractionIndex, @NotNull Texture texture) implements Material {
+public record DielectricMaterial(double refractionIndex, @NotNull Color albedo) implements Material {
     public DielectricMaterial(double refractionIndex) {
         this(refractionIndex, Color.WHITE);
     }
 
     public DielectricMaterial {
-        Objects.requireNonNull(texture, "texture");
+        Objects.requireNonNull(albedo, "albedo");
     }
 
     @Override
     public @NotNull Optional<ScatterResult> scatter(@NotNull Ray ray, @NotNull HitResult hit, @NotNull RandomGenerator random) {
-        var ri = hit.isFrontFace() ? (1 / refractionIndex) : refractionIndex;
+        var ri = hit.frontFace() ? (1 / refractionIndex) : refractionIndex;
 
         var cosTheta = Math.min(- ray.direction().unit().times(hit.normal()), 1.0);
         var reflectance = reflectance(cosTheta);
@@ -31,8 +30,7 @@ public record DielectricMaterial(double refractionIndex, @NotNull Texture textur
         var newDirection = (reflect ? Optional.<Vec3>empty() : Vec3.refract(ray.direction(), hit.normal(), ri))
                 .orElseGet(() -> Vec3.reflect(ray.direction(), hit.normal()));
 
-        var attenuation = texture.get(hit);
+        return Optional.of(new ScatterResult(new Ray(hit.position(), newDirection), albedo));
-        return Optional.of(new SpecularScatterResult(attenuation, new Ray(hit.position(), newDirection)));
     }
 
     private double reflectance(double cos) {

src/main/java/eu/jonahbauer/raytracing/render/material/DiffuseLight.java

@@ -1,15 +1,14 @@
 package eu.jonahbauer.raytracing.render.material;
 
 import eu.jonahbauer.raytracing.math.Ray;
-import eu.jonahbauer.raytracing.render.texture.Color;
+import eu.jonahbauer.raytracing.render.Color;
-import eu.jonahbauer.raytracing.render.texture.Texture;
 import eu.jonahbauer.raytracing.scene.HitResult;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.Optional;
 import java.util.random.RandomGenerator;
 
-public record DiffuseLight(@NotNull Texture texture) implements Material {
+public record DiffuseLight(@NotNull Color emit) implements Material {
     @Override
     public @NotNull Optional<ScatterResult> scatter(@NotNull Ray ray, @NotNull HitResult hit, @NotNull RandomGenerator random) {
         return Optional.empty();
@@ -17,6 +16,6 @@ public record DiffuseLight(@NotNull Texture texture) implements Material {
 
     @Override
     public @NotNull Color emitted(@NotNull HitResult hit) {
-        return texture.get(hit);
+        return emit;
     }
 }

src/main/java/eu/jonahbauer/raytracing/render/material/DirectionalMaterial.java

@@ -1,68 +0,0 @@
-package eu.jonahbauer.raytracing.render.material;
-
-import eu.jonahbauer.raytracing.math.Ray;
-import eu.jonahbauer.raytracing.math.Vec3;
-import eu.jonahbauer.raytracing.render.texture.Color;
-import eu.jonahbauer.raytracing.render.texture.Texture;
-import eu.jonahbauer.raytracing.scene.HitResult;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-
-import java.util.Optional;
-import java.util.random.RandomGenerator;
-
-public final class DirectionalMaterial implements Material {
-    private final @Nullable Material front;
-    private final @Nullable Material back;
-
-    private final @NotNull Texture texture;
-
-    public DirectionalMaterial(@Nullable Material front, @Nullable Material back) {
-        if (front == null && back == null) throw new IllegalArgumentException("front and back must not both be null");
-        this.front = front;
-        this.back = back;
-        this.texture = new DirectionalTexture(
-                front != null ? front.texture() : null,
-                back != null ? back.texture() : null
-        );
-    }
-
-    @Override
-    public @NotNull Texture texture() {
-        return texture;
-    }
-
-    @Override
-    public @NotNull Optional<ScatterResult> scatter(@NotNull Ray ray, @NotNull HitResult hit, @NotNull RandomGenerator random) {
-        if (hit.isFrontFace()) {
-            if (front != null) return front.scatter(ray, hit, random);
-        } else {
-            if (back != null) return back.scatter(ray, hit, random);
-        }
-        // let the ray pass through without obstruction
-        return Optional.of(new SpecularScatterResult(Color.WHITE, new Ray(ray.at(hit.t()), ray.direction())));
-    }
-
-    @Override
-    public @NotNull Color emitted(@NotNull HitResult hit) {
-        if (hit.isFrontFace()) {
-            if (front != null) return front.emitted(hit);
-        } else {
-            if (back != null) return back.emitted(hit);
-        }
-        return Material.super.emitted(hit);
-    }
-
-    private record DirectionalTexture(@Nullable Texture front, @Nullable Texture back) implements Texture {
-
-        @Override
-        public @NotNull Color get(double u, double v, @NotNull Vec3 p) {
-            throw new UnsupportedOperationException();
-        }
-
-        @Override
-        public boolean isUVRequired() {
-            return front() != null && front().isUVRequired() || back() != null && back().isUVRequired();
-        }
-    }
-}

src/main/java/eu/jonahbauer/raytracing/render/material/IsotropicMaterial.java

@@ -1,23 +1,17 @@
 package eu.jonahbauer.raytracing.render.material;
 
 import eu.jonahbauer.raytracing.math.Ray;
-import eu.jonahbauer.raytracing.render.renderer.pdf.SphereProbabilityDensityFunction;
+import eu.jonahbauer.raytracing.math.Vec3;
-import eu.jonahbauer.raytracing.render.texture.Color;
+import eu.jonahbauer.raytracing.render.Color;
-import eu.jonahbauer.raytracing.render.texture.Texture;
 import eu.jonahbauer.raytracing.scene.HitResult;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.Optional;
 import java.util.random.RandomGenerator;
 
-public record IsotropicMaterial(@NotNull Color albedo) implements Material {
+public record IsotropicMaterial(@NotNull Color albedo) implements Material{
     @Override
     public @NotNull Optional<ScatterResult> scatter(@NotNull Ray ray, @NotNull HitResult hit, @NotNull RandomGenerator random) {
-        return Optional.of(new PdfScatterResult(albedo(), new SphereProbabilityDensityFunction()));
+        return Optional.of(new ScatterResult(new Ray(hit.position(), Vec3.random(random, true)), albedo()));
-    }
-
-    @Override
-    public @NotNull Texture texture() {
-        return albedo();
     }
 }

src/main/java/eu/jonahbauer/raytracing/render/material/LambertianMaterial.java

@@ -1,8 +1,8 @@
 package eu.jonahbauer.raytracing.render.material;
 
 import eu.jonahbauer.raytracing.math.Ray;
-import eu.jonahbauer.raytracing.render.renderer.pdf.CosineProbabilityDensityFunction;
+import eu.jonahbauer.raytracing.math.Vec3;
-import eu.jonahbauer.raytracing.render.texture.Texture;
+import eu.jonahbauer.raytracing.render.Color;
 import eu.jonahbauer.raytracing.scene.HitResult;
 import org.jetbrains.annotations.NotNull;
 
@@ -10,14 +10,17 @@ import java.util.Objects;
 import java.util.Optional;
 import java.util.random.RandomGenerator;
 
-public record LambertianMaterial(@NotNull Texture texture) implements Material {
+public record LambertianMaterial(@NotNull Color albedo) implements Material {
     public LambertianMaterial {
-        Objects.requireNonNull(texture, "texture");
+        Objects.requireNonNull(albedo, "albedo");
     }
 
     @Override
     public @NotNull Optional<ScatterResult> scatter(@NotNull Ray ray, @NotNull HitResult hit, @NotNull RandomGenerator random) {
-        var attenuation = texture.get(hit);
+        var newDirection = hit.normal().plus(Vec3.random(random, true));
-        return Optional.of(new PdfScatterResult(attenuation, new CosineProbabilityDensityFunction(hit.normal())));
+        if (newDirection.isNearZero()) newDirection = hit.normal();
+
+        var scattered = new Ray(hit.position(), newDirection);
+        return Optional.of(new ScatterResult(scattered, albedo));
     }
 }

src/main/java/eu/jonahbauer/raytracing/render/material/Material.java

@@ -1,9 +1,7 @@
 package eu.jonahbauer.raytracing.render.material;
 
 import eu.jonahbauer.raytracing.math.Ray;
-import eu.jonahbauer.raytracing.render.renderer.pdf.ProbabilityDensityFunction;
+import eu.jonahbauer.raytracing.render.Color;
-import eu.jonahbauer.raytracing.render.texture.Color;
-import eu.jonahbauer.raytracing.render.texture.Texture;
 import eu.jonahbauer.raytracing.scene.HitResult;
 import org.jetbrains.annotations.NotNull;
 
@@ -13,59 +11,16 @@ import java.util.random.RandomGenerator;
 
 public interface Material {
 
-    /**
-     * {@return the texture associated with this material}
-     */
-    @NotNull Texture texture();
-
-    /**
-     * Scatters a light ray after it hit a surface.
-     * @param ray the incoming light ray
-     * @param hit information about the light ray hitting some object
-     * @param random a random number generator
-     * @return a {@code ScatterResult} if the ray is scattered or an {@linkplain Optional#empty() empty optional} if the
-     * ray is absorbed.
-     */
     @NotNull Optional<ScatterResult> scatter(@NotNull Ray ray, @NotNull HitResult hit, @NotNull RandomGenerator random);
 
-    /**
-     * {@return the color emitted for a given hit}
-     * @implSpec the default implementation returns {@linkplain Color#BLACK black}, i.e. no emission
-     */
     default @NotNull Color emitted(@NotNull HitResult hit) {
         return Color.BLACK;
     }
 
-    /**
+    record ScatterResult(@NotNull Ray ray, @NotNull Color attenuation) {
-     * The result of a {@linkplain Material#scatter(Ray, HitResult, RandomGenerator) scattering operation}.
+        public ScatterResult {
-     */
-    sealed interface ScatterResult {}
-
-    /**
-     * The result of a specular {@linkplain #scatter(Ray, HitResult, RandomGenerator) scattering operation}. A
-     * specular is a scattering operation with a very small number of possible scattered rays (like a
-     * perfect reflection which only has one possible scattered ray).
-     * @param attenuation the attenuation of the scattered light ray
-     * @param ray the scattered light ray
-     */
-    record SpecularScatterResult(@NotNull Color attenuation, @NotNull Ray ray) implements ScatterResult {
-        public SpecularScatterResult {
-            Objects.requireNonNull(attenuation, "attenuation");
             Objects.requireNonNull(ray, "ray");
-        }
-    }
-
-    /**
-     * The result of a probability density function based
-     * {@linkplain #scatter(Ray, HitResult, RandomGenerator) scattering operation}. A probability density function
-     * based scattering operation uses a probability density function to determine the scatter direction.
-     * @param attenuation the attenuation of the scattered light ray
-     * @param pdf the probability density function
-     */
-    record PdfScatterResult(@NotNull Color attenuation, @NotNull ProbabilityDensityFunction pdf) implements ScatterResult {
-        public PdfScatterResult {
             Objects.requireNonNull(attenuation, "attenuation");
-            Objects.requireNonNull(pdf, "pdf");
         }
     }
 }

src/main/java/eu/jonahbauer/raytracing/render/material/MetallicMaterial.java

@@ -2,7 +2,7 @@ package eu.jonahbauer.raytracing.render.material;
 
 import eu.jonahbauer.raytracing.math.Ray;
 import eu.jonahbauer.raytracing.math.Vec3;
-import eu.jonahbauer.raytracing.render.texture.Texture;
+import eu.jonahbauer.raytracing.render.Color;
 import eu.jonahbauer.raytracing.scene.HitResult;
 import org.jetbrains.annotations.NotNull;
 
@@ -10,14 +10,14 @@ import java.util.Objects;
 import java.util.Optional;
 import java.util.random.RandomGenerator;
 
-public record MetallicMaterial(@NotNull Texture texture, double fuzz) implements Material {
+public record MetallicMaterial(@NotNull Color albedo, double fuzz) implements Material {
 
-    public MetallicMaterial(@NotNull Texture texture) {
+    public MetallicMaterial(@NotNull Color albedo) {
-        this(texture, 0);
+        this(albedo, 0);
     }
 
     public MetallicMaterial {
-        Objects.requireNonNull(texture, "texture");
+        Objects.requireNonNull(albedo, "albedo");
         if (fuzz < 0 || !Double.isFinite(fuzz)) throw new IllegalArgumentException("fuzz must be non-negative");
     }
 
@@ -25,9 +25,8 @@ public record MetallicMaterial(@NotNull Texture texture, double fuzz) implements
     public @NotNull Optional<ScatterResult> scatter(@NotNull Ray ray, @NotNull HitResult hit, @NotNull RandomGenerator random) {
         var newDirection = Vec3.reflect(ray.direction(), hit.normal());
         if (fuzz > 0) {
-            newDirection = Vec3.fma(fuzz, Vec3.random(random), newDirection.unit());
+            newDirection = newDirection.unit().plus(Vec3.random(random, true).times(fuzz));
         }
-        var attenuation = texture.get(hit);
+        return Optional.of(new ScatterResult(new Ray(hit.position(), newDirection), albedo));
-        return Optional.of(new SpecularScatterResult(attenuation, new Ray(hit.position(), newDirection)));
     }
 }

src/main/java/eu/jonahbauer/raytracing/render/renderer/SimpleRenderer.java

@@ -2,10 +2,7 @@ package eu.jonahbauer.raytracing.render.renderer;
 
 import eu.jonahbauer.raytracing.math.Range;
 import eu.jonahbauer.raytracing.math.Ray;
-import eu.jonahbauer.raytracing.render.material.Material;
+import eu.jonahbauer.raytracing.render.Color;
-import eu.jonahbauer.raytracing.render.renderer.pdf.TargetingProbabilityDensityFunction;
-import eu.jonahbauer.raytracing.render.renderer.pdf.MixtureProbabilityDensityFunction;
-import eu.jonahbauer.raytracing.render.texture.Color;
 import eu.jonahbauer.raytracing.render.camera.Camera;
 import eu.jonahbauer.raytracing.render.canvas.Canvas;
 import eu.jonahbauer.raytracing.scene.Scene;
@@ -16,10 +13,8 @@ import java.util.SplittableRandom;
 import java.util.random.RandomGenerator;
 import java.util.stream.IntStream;
 
-import static eu.jonahbauer.raytracing.Main.DEBUG;
-
 public final class SimpleRenderer implements Renderer {
-    private final int sqrtSamplesPerPixel;
+    private final int samplesPerPixel;
     private final int maxDepth;
     private final double gamma;
 
@@ -35,7 +30,7 @@ public final class SimpleRenderer implements Renderer {
     }
 
     private SimpleRenderer(@NotNull Builder builder) {
-        this.sqrtSamplesPerPixel = (int) Math.sqrt(builder.samplesPerPixel);
+        this.samplesPerPixel = builder.samplesPerPixel;
         this.maxDepth = builder.maxDepth;
         this.gamma = builder.gamma;
 
@@ -43,9 +38,6 @@ public final class SimpleRenderer implements Renderer {
         this.iterative = builder.iterative;
     }
 
-    /**
-     * {@inheritDoc}
-     */
     @Override
     public void render(@NotNull Camera camera, @NotNull Scene scene, @NotNull Canvas canvas) {
         if (canvas.getWidth() != camera.getWidth() || canvas.getHeight() != camera.getHeight()) {
@@ -53,69 +45,42 @@ public final class SimpleRenderer implements Renderer {
         }
 
         if (iterative) {
-            renderIterative(camera, scene, canvas);
+            var random = new Random();
-        } else {
-            renderNonIterative(camera, scene, canvas);
-        }
-    }
 
-    /**
+            // render one sample after the other
-     * Renders the {@code scene} as seen by the {@code camera} to the {@code canvas}, taking one sample per pixel at
+            for (int i = 1 ; i <= samplesPerPixel; i++) {
-     * a time and updating the canvas after each sample.
+                var sample = i;
-     */
-    private void renderIterative(@NotNull Camera camera, @NotNull Scene scene, @NotNull Canvas canvas) {
-        var random = new Random(0);
-
-        // render one sample after the other
-        int i = 0;
-        for (int sj = 0; sj < sqrtSamplesPerPixel; sj++) {
-            for (int si = 0; si < sqrtSamplesPerPixel; si++) {
-                var sample = ++i;
-                var sif = si;
-                var sjf = sj;
                 getScanlineStream(camera.getHeight(), parallel).forEach(y -> {
                     for (int x = 0; x < camera.getWidth(); x++) {
-                        var ray = camera.cast(x, y, sif, sjf, sqrtSamplesPerPixel, random);
+                        var ray = camera.cast(x, y, random);
                         var c = getColor(scene, ray, random);
                         canvas.set(x, y, Color.average(canvas.get(x, y), c, sample));
                     }
                 });
             }
-        }
 
-        // apply gamma correction
+            // apply gamma correction
-        getScanlineStream(camera.getHeight(), parallel).forEach(y -> {
+            getScanlineStream(camera.getHeight(), parallel).forEach(y -> {
-            for (int x = 0; x < camera.getWidth(); x++) {
+                for (int x = 0; x < camera.getWidth(); x++) {
-                canvas.set(x, y, Color.gamma(canvas.get(x, y), gamma));
+                    canvas.set(x, y, Color.gamma(canvas.get(x, y), gamma));
-            }
-        });
-    }
-
-    /**
-     * Renders the {@code scene} as seen by the {@code camera} to the {@code canvas}, taking some amount of samples
-     * per pixel and updating the canvas after each pixel.
-     */
-    private void renderNonIterative(@NotNull Camera camera, @NotNull Scene scene, @NotNull Canvas canvas) {
-        var splittable = new SplittableRandom(0);
-        // render one pixel after the other
-        getScanlineStream(camera.getHeight(), parallel).forEach(y -> {
-            var random = splittable.split();
-            for (int x = 0; x < camera.getWidth(); x++) {
-                var color = Color.BLACK;
-                int i = 0;
-                for (int sj = 0; sj < sqrtSamplesPerPixel; sj++) {
-                    for (int si = 0; si < sqrtSamplesPerPixel; si++) {
-                        var ray = camera.cast(x, y, si, sj, sqrtSamplesPerPixel, random);
-                        if (DEBUG) {
-                            System.out.println("Casting ray " + ray + " through pixel (" + x + "," + y + ") at subpixel (" + si + "," + sj + ")...");
-                        }
-                        var c = getColor(scene, ray, random);
-                        color = Color.average(color, c, ++i);
-                    }
                 }
-                canvas.set(x, y, Color.gamma(color, gamma));
+            });
-            }
+        } else {
-        });
+            var splittable = new SplittableRandom();
+            // render one pixel after the other
+            getScanlineStream(camera.getHeight(), parallel).forEach(y -> {
+                var random = splittable.split();
+                for (int x = 0; x < camera.getWidth(); x++) {
+                    var color = Color.BLACK;
+                    for (int i = 1; i <= samplesPerPixel; i++) {
+                        var ray = camera.cast(x, y, random);
+                        var c = getColor(scene, ray, random);
+                        color = Color.average(color, c, i);
+                    }
+                    canvas.set(x, y, Color.gamma(color, gamma));
+                }
+            });
+        }
     }
 
     /**
@@ -130,82 +95,21 @@ public final class SimpleRenderer implements Renderer {
         var attenuation = Color.WHITE;
 
         while (depth-- > 0) {
-            var optional = scene.hit(ray);
+            var optional = scene.hit(ray, new Range(0.001, Double.POSITIVE_INFINITY));
             if (optional.isEmpty()) {
-                var background = scene.getBackgroundColor(ray);
+                color = Color.add(color, Color.multiply(attenuation, scene.getBackgroundColor(ray)));
-                color = Color.add(color, Color.multiply(attenuation, background));
-                if (DEBUG) {
-                    System.out.println("  Hit background: " + background);
-                }
                 break;
             }
 
             var hit = optional.get();
-            if (DEBUG) {
-                System.out.println("  Hit " + hit.target() + " at t=" + hit.t() + " (" + hit.position() + ")");
-            }
             var material = hit.material();
             var emitted = material.emitted(hit);
-            if (DEBUG && !Color.BLACK.equals(emitted)) {
+            var scatter = material.scatter(ray, hit, random);
-                System.out.println("  Emitted: " + emitted);
-            }
-
-            var result = material.scatter(ray, hit, random);
             color = Color.add(color, Color.multiply(attenuation, emitted));
 
-            if (result.isEmpty()) {
+            if (scatter.isEmpty()) break;
-                if (DEBUG) {
+            attenuation = Color.multiply(attenuation, scatter.get().attenuation());
-                    System.out.println("  Absorbed");
+            ray = scatter.get().ray();
-                }
-                break;
-            }
-
-            switch (result.get()) {
-                case Material.SpecularScatterResult(var a, var scattered) -> {
-                    attenuation = Color.multiply(attenuation, a);
-                    ray = scattered;
-
-                    if (DEBUG) {
-                        System.out.println("  Specular scattering with albedo " + a);
-                    }
-                }
-                case Material.PdfScatterResult(var a, var pdf) -> {
-                    if (scene.getTargets() == null) {
-                        attenuation = Color.multiply(attenuation, a);
-                        ray = new Ray(hit.position(), pdf.generate(random));
-
-                        if (DEBUG) {
-                            System.out.println("  Pdf scattering with albedo " + a);
-                        }
-                    } else {
-                        var mixed = new MixtureProbabilityDensityFunction(new TargetingProbabilityDensityFunction(hit.position(), scene.getTargets()), pdf, 0.5);
-                        var direction = mixed.generate(random).unit();
-
-                        var idealPdf = pdf.value(direction);
-                        var actualPdf = mixed.value(direction);
-                        if (actualPdf == 0) break; // when actualPdf is 0, the ray should have never been generated by mixed.generate
-
-                        var factor =  idealPdf / actualPdf;
-
-                        attenuation = Color.multiply(attenuation, Color.multiply(a, factor));
-                        ray = new Ray(hit.position(), direction);
-
-                        if (DEBUG) {
-                            System.out.println("  Pdf scattering with albedo " + a + " and factor " + factor);
-                        }
-                    }
-                }
-            }
-
-            if (DEBUG) {
-                System.out.println("  Combined color is " + color);
-                System.out.println("  Combined attenuation is " + attenuation);
-                System.out.println("  New ray is " + ray);
-            }
-        }
-
-        if (DEBUG) {
-            System.out.println("  Final color is " + color);
         }
 
         return color;

src/main/java/eu/jonahbauer/raytracing/render/renderer/pdf/CosineProbabilityDensityFunction.java

@@ -1,27 +0,0 @@
-package eu.jonahbauer.raytracing.render.renderer.pdf;
-
-import eu.jonahbauer.raytracing.math.Vec3;
-import org.jetbrains.annotations.NotNull;
-
-import java.util.Objects;
-import java.util.random.RandomGenerator;
-
-public record CosineProbabilityDensityFunction(@NotNull Vec3 normal) implements ProbabilityDensityFunction {
-
-    public CosineProbabilityDensityFunction {
-        Objects.requireNonNull(normal, "normal");
-        normal = normal.unit();
-    }
-
-    @Override
-    public double value(@NotNull Vec3 direction) {
-        var cos = normal.times(direction);
-        return Math.max(0, cos / Math.PI);
-    }
-
-    @Override
-    public @NotNull Vec3 generate(@NotNull RandomGenerator random) {
-        var out = normal().plus(Vec3.random(random));
-        return out.isNearZero() ? normal() : out;
-    }
-}

src/main/java/eu/jonahbauer/raytracing/render/renderer/pdf/MixtureProbabilityDensityFunction.java

@@ -1,46 +0,0 @@
-package eu.jonahbauer.raytracing.render.renderer.pdf;
-
-import eu.jonahbauer.raytracing.math.Vec3;
-import org.jetbrains.annotations.NotNull;
-
-import java.util.Objects;
-import java.util.random.RandomGenerator;
-
-/**
- * Mixes between two probability density functions (pdf) using a weight. When the weight is closer to zero, the
- * influence of the second pdf is stronger. When the weight is closer to one, the influence of the first pdf is stronger.
- * @param a the first probability density function
- * @param b the second probability density function
- * @param weight a weight in the range [0, 1]
- */
-public record MixtureProbabilityDensityFunction(
-        @NotNull ProbabilityDensityFunction a,
-        @NotNull ProbabilityDensityFunction b,
-        double weight
-) implements ProbabilityDensityFunction {
-    public MixtureProbabilityDensityFunction(@NotNull ProbabilityDensityFunction a, @NotNull ProbabilityDensityFunction b) {
-        this(a, b, 0.5);
-    }
-
-    public MixtureProbabilityDensityFunction {
-        Objects.requireNonNull(a);
-        Objects.requireNonNull(b);
-        weight = Math.clamp(weight, 0, 1);
-    }
-
-    @Override
-    public double value(@NotNull Vec3 direction) {
-        var v = a.value(direction);
-        var w = b.value(direction);
-        return Math.fma(weight, v, Math.fma(-weight, w, w));
-    }
-
-    @Override
-    public @NotNull Vec3 generate(@NotNull RandomGenerator random) {
-        if (random.nextDouble() < weight) {
-            return a.generate(random);
-        } else {
-            return b.generate(random);
-        }
-    }
-}

src/main/java/eu/jonahbauer/raytracing/render/renderer/pdf/ProbabilityDensityFunction.java

@@ -1,25 +0,0 @@
-package eu.jonahbauer.raytracing.render.renderer.pdf;
-
-import eu.jonahbauer.raytracing.math.Vec3;
-import org.jetbrains.annotations.NotNull;
-
-import java.util.random.RandomGenerator;
-
-/**
- * A probability density function used for sampling random directions when scattering a ray.
- */
-public interface ProbabilityDensityFunction {
-
-    /**
-     * {@return the value of this probability density function at the given point}
-     * @param direction the direction
-     */
-    double value(@NotNull Vec3 direction);
-
-    /**
-     * Generates a random direction based on this probability density function.
-     * @param random a random number generator
-     * @return the random direction
-     */
-    @NotNull Vec3 generate(@NotNull RandomGenerator random);
-}

src/main/java/eu/jonahbauer/raytracing/render/renderer/pdf/SphereProbabilityDensityFunction.java

@@ -1,22 +0,0 @@
-package eu.jonahbauer.raytracing.render.renderer.pdf;
-
-import eu.jonahbauer.raytracing.math.Vec3;
-import org.jetbrains.annotations.NotNull;
-
-import java.util.random.RandomGenerator;
-
-/**
- * A probability density function sampling the sphere uniformly.
- */
-public record SphereProbabilityDensityFunction() implements ProbabilityDensityFunction {
-
-    @Override
-    public double value(@NotNull Vec3 direction) {
-        return 1 / (4 * Math.PI);
-    }
-
-    @Override
-    public @NotNull Vec3 generate(@NotNull RandomGenerator random) {
-        return Vec3.random(random);
-    }
-}

src/main/java/eu/jonahbauer/raytracing/render/renderer/pdf/TargetingProbabilityDensityFunction.java

@@ -1,41 +0,0 @@
-package eu.jonahbauer.raytracing.render.renderer.pdf;
-
-import eu.jonahbauer.raytracing.math.Vec3;
-import eu.jonahbauer.raytracing.scene.Target;
-import org.jetbrains.annotations.NotNull;
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Objects;
-import java.util.random.RandomGenerator;
-
-/**
- * A probability density function targeting a target.
- * @see Target
- */
-public final class TargetingProbabilityDensityFunction implements ProbabilityDensityFunction {
-    private final @NotNull Vec3 origin;
-    private final @NotNull List<@NotNull Target> targets;
-
-    public TargetingProbabilityDensityFunction(@NotNull Vec3 origin, @NotNull List<@NotNull Target> targets) {
-        this.origin = Objects.requireNonNull(origin, "origin");
-        this.targets = new ArrayList<>(targets);
-    }
-
-    @Override
-    public double value(@NotNull Vec3 direction) {
-        var weight = 1d / targets.size();
-        var sum = 0.0;
-
-        for (var target : targets) {
-            sum = Math.fma(weight, target.getProbabilityDensity(origin, direction), sum);
-        }
-
-        return sum;
-    }
-
-    @Override
-    public @NotNull Vec3 generate(@NotNull RandomGenerator random) {
-        return targets.get(random.nextInt(targets.size())).getTargetingDirection(origin, random);
-    }
-}

src/main/java/eu/jonahbauer/raytracing/render/texture/CheckerTexture.java

@@ -1,21 +0,0 @@
-package eu.jonahbauer.raytracing.render.texture;
-
-import eu.jonahbauer.raytracing.math.Vec3;
-import org.jetbrains.annotations.NotNull;
-
-public record CheckerTexture(double scale, @NotNull Texture even, @NotNull Texture odd) implements Texture {
-
-    @Override
-    public @NotNull Color get(double u, double v, @NotNull Vec3 p) {
-        var x = (int) Math.floor(p.x() / scale);
-        var y = (int) Math.floor(p.y() / scale);
-        var z = (int) Math.floor(p.z() / scale);
-        var even = (x + y + z) % 2 == 0;
-        return even ? even().get(u, v, p) : odd().get(u, v, p);
-    }
-
-    @Override
-    public boolean isUVRequired() {
-        return even.isUVRequired() || odd.isUVRequired();
-    }
-}

src/main/java/eu/jonahbauer/raytracing/render/texture/ImageTexture.java

@@ -1,43 +0,0 @@
-package eu.jonahbauer.raytracing.render.texture;
-
-import eu.jonahbauer.raytracing.math.Vec3;
-import eu.jonahbauer.raytracing.render.canvas.Image;
-import org.jetbrains.annotations.NotNull;
-
-import javax.imageio.ImageIO;
-import java.awt.image.BufferedImage;
-import java.io.IOException;
-import java.io.UncheckedIOException;
-import java.util.Objects;
-
-public record ImageTexture(@NotNull Image image) implements Texture {
-
-    public ImageTexture {
-        Objects.requireNonNull(image, "image");
-    }
-
-    public ImageTexture(@NotNull BufferedImage image) {
-        this(new Image(image));
-    }
-
-    public ImageTexture(@NotNull String path) {
-        this(read(path));
-    }
-
-    private static @NotNull BufferedImage read(@NotNull String path) {
-        try (var in = Objects.requireNonNull(ImageTexture.class.getResourceAsStream(path))) {
-            return ImageIO.read(in);
-        } catch (IOException ex) {
-            throw new UncheckedIOException(ex);
-        }
-    }
-
-    @Override
-    public @NotNull Color get(double u, double v, @NotNull Vec3 p) {
-        u = Math.clamp(u, 0, 1);
-        v = 1 - Math.clamp(v, 0, 1);
-        int x = (int) (u * (image.getWidth() - 1));
-        int y = (int) (v * (image.getHeight() - 1));
-        return image.get(x, y);
-    }
-}

src/main/java/eu/jonahbauer/raytracing/render/texture/PerlinTexture.java

@@ -1,152 +0,0 @@
-package eu.jonahbauer.raytracing.render.texture;
-
-import eu.jonahbauer.raytracing.math.Vec3;
-import org.jetbrains.annotations.NotNull;
-
-import java.util.Objects;
-import java.util.Random;
-import java.util.function.DoubleFunction;
-import java.util.random.RandomGenerator;
-
-public final class PerlinTexture implements Texture {
-    private static final int POINT_COUNT = 256;
-    private static final @NotNull Random RANDOM = new Random();
-    private static final @NotNull DoubleFunction<Color> GREYSCALE = t -> new Color(t, t, t);
-
-    private final double scale;
-    private final int turbulence;
-    private final @NotNull DoubleFunction<Color> color;
-
-    private final int mask;
-    private final Vec3[] randvec;
-    private final int[] permX;
-    private final int[] permY;
-    private final int[] permZ;
-
-    public PerlinTexture() {
-        this(1.0);
-    }
-
-    public PerlinTexture(double scale) {
-        this(scale, 7);
-    }
-
-    public PerlinTexture(double scale, int turbulence) {
-        this(scale, turbulence, GREYSCALE);
-    }
-
-    public PerlinTexture(double scale, int turbulence, @NotNull DoubleFunction<Color> color) {
-        this(scale, turbulence, color, POINT_COUNT, RANDOM);
-    }
-
-    public PerlinTexture(
-            double scale, int turbulence, @NotNull DoubleFunction<Color> color,
-            int count, @NotNull RandomGenerator random
-    ) {
-        if ((count & (count - 1)) != 0) throw new IllegalArgumentException("count must be a power of two");
-        if (turbulence <= 0) throw new IllegalArgumentException("turbulence must be positive");
-
-        this.scale = scale;
-        this.turbulence = turbulence;
-        this.color = Objects.requireNonNull(color, "color");
-
-        this.mask = count - 1;
-        this.randvec = new Vec3[count];
-        for (int i = 0; i < count; i++) {
-            this.randvec[i] = Vec3.random(random);
-        }
-        this.permX = generatePerm(count, random);
-        this.permY = generatePerm(count, random);
-        this.permZ = generatePerm(count, random);
-    }
-
-    private static int @NotNull[] generatePerm(int count, @NotNull RandomGenerator random) {
-        int[] p = new int[count];
-        for (int i = 0; i < count; i++) {
-            p[i] = i;
-        }
-        permutate(p, random);
-        return p;
-    }
-
-    private static void permutate(int @NotNull[] p, @NotNull RandomGenerator random) {
-        for (int i = p.length - 1; i > 0; i--) {
-            int target = random.nextInt(i);
-            int tmp = p[i];
-            p[i] = p[target];
-            p[target] = tmp;
-        }
-    }
-
-    public double getNoise(@NotNull Vec3 p) {
-        var x = p.x() * scale;
-        var y = p.y() * scale;
-        var z = p.z() * scale;
-
-        var u = x - Math.floor(x);
-        var v = y - Math.floor(y);
-        var w = z - Math.floor(z);
-
-        int i = (int) Math.floor(x);
-        int j = (int) Math.floor(y);
-        int k = (int) Math.floor(z);
-
-        var c = new Vec3[8];
-        for (int di = 0; di < 2; di++) {
-            for (int dj = 0; dj < 2; dj++) {
-                for (int dk = 0; dk < 2; dk++) {
-                    c[di << 2 | dj << 1 | dk] = randvec[permX[(i + di) & mask] ^ permY[(j + dj) & mask] ^ permZ[(k + dk) & mask]];
-                }
-            }
-        }
-
-        return interpolate(c, u, v, w);
-    }
-
-    public double getNoise(@NotNull Vec3 p, int depth) {
-        var accum = 0.0;
-        var temp = p;
-        var weight = 1.0;
-
-        for (int i = 0; i < depth; i++) {
-            accum = Math.fma(weight, getNoise(temp), accum);
-            weight *= 0.5;
-            temp = temp.times(2);
-        }
-
-        return accum;
-    }
-
-    @Override
-    public @NotNull Color get(double u, double v, @NotNull Vec3 p) {
-        var noise = getNoise(p, turbulence);
-        var t = Math.fma(0.5, Math.sin(Math.PI * noise), 0.5);
-        return color.apply(t);
-    }
-
-    private static double interpolate(Vec3[] c, double u, double v, double w) {
-        var uu = u * u * Math.fma(-2, u, 3);
-        var vv = v * v * Math.fma(-2, v, 3);
-        var ww = w * w * Math.fma(-2, w, 3);
-
-        var accum = 0.0;
-        for (int i = 0; i < 2; i++) {
-            for (int j = 0; j < 2; j++) {
-                for (int k = 0; k < 2; k++) {
-                    var vec = c[i << 2 | j << 1 | k];
-                    var dot = (u - i) * vec.x() + (v - j) * vec.y() + (w - k) * vec.z();
-                    accum += Math.fma(i, uu, (1 - i) * (1 - uu))
-                             * Math.fma(j, vv, (1 - j) * (1 - vv))
-                             * Math.fma(k, ww, (1 - k) * (1 - ww))
-                             * dot;
-                }
-            }
-        }
-        return accum;
-    }
-
-    @Override
-    public boolean isUVRequired() {
-        return false;
-    }
-}

src/main/java/eu/jonahbauer/raytracing/render/texture/Texture.java

@@ -1,32 +0,0 @@
-package eu.jonahbauer.raytracing.render.texture;
-
-import eu.jonahbauer.raytracing.math.Vec3;
-import eu.jonahbauer.raytracing.scene.HitResult;
-import org.jetbrains.annotations.NotNull;
-
-public interface Texture {
-    /**
-     * {@return the color of <code>this</code> texture for a hit}
-     */
-    default @NotNull Color get(@NotNull HitResult hit) {
-        return get(hit.u(), hit.v(), hit.position());
-    }
-
-    /**
-     * {@return the color of <code>this</code> texture at the specified position}
-     * @param u the texture u coordinate
-     * @param v the texture v coordinate
-     * @param p the position
-     */
-    @NotNull Color get(double u, double v, @NotNull Vec3 p);
-
-    /**
-     * Returns whether {@link #get(double, double, Vec3)} uses the {@code u} and/or {@code v} parameters.
-     * When a texture indicates that the {@code u} and {@code v} coordinates are not required, the calculation may be
-     * skipped and {@link Double#NaN} will be passed.
-     * @return whether {@link #get(double, double, Vec3)} uses the {@code u} and/or {@code v} parameters
-     */
-    default boolean isUVRequired() {
-        return true;
-    }
-}

src/main/java/eu/jonahbauer/raytracing/scene/HitResult.java

@@ -1,38 +1,23 @@
 package eu.jonahbauer.raytracing.scene;
 
-import eu.jonahbauer.raytracing.math.Range;
-import eu.jonahbauer.raytracing.math.Ray;
 import eu.jonahbauer.raytracing.math.Vec3;
 import eu.jonahbauer.raytracing.render.material.Material;
-import eu.jonahbauer.raytracing.render.texture.Texture;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.Objects;
 
-/**
- * The result of a {@linkplain Hittable#hit(Ray, Range) hit}.
- * @param t the {@code t} value at which the hit occurs
- * @param position the position of the hit
- * @param normal the surface normal at the hit position
- * @param target the hit target (for debug purposes only)
- * @param material the material of the surface
- * @param u the texture u coordinate (or {@code Double.NaN} if the {@linkplain Material#texture() material's texture} does {@linkplain Texture#isUVRequired() not depend} on the uv-coordinates)
- * @param v the texture v coordinate (or {@code Double.NaN} if the {@linkplain Material#texture() material's texture} does {@linkplain Texture#isUVRequired() not depend} on the uv-coordinates)
- * @param isFrontFace whether the front or the back of the surface was it
- */
 public record HitResult(
-        double t, @NotNull Vec3 position, @NotNull Vec3 normal, @NotNull Hittable target,
+        double t,
-        @NotNull Material material, double u, double v, boolean isFrontFace
+        @NotNull Vec3 position,
+        @NotNull Vec3 normal,
+        @NotNull Material material,
+        boolean frontFace
 ) implements Comparable<HitResult> {
     public HitResult {
         Objects.requireNonNull(position, "position");
         normal = normal.unit();
     }
 
-    public @NotNull HitResult withPositionAndNormal(@NotNull Vec3 position, @NotNull Vec3 normal) {
-        return new HitResult(t, position, normal, target, material, u, v, isFrontFace);
-    }
-
     @Override
     public int compareTo(@NotNull HitResult o) {
         return Double.compare(t, o.t);

src/main/java/eu/jonahbauer/raytracing/scene/Hittable.java

@@ -11,38 +11,21 @@ import org.jetbrains.annotations.NotNull;
 import java.util.Optional;
 
 public interface Hittable {
-    @NotNull Range FORWARD = new Range(0.001, Double.POSITIVE_INFINITY);
 
     /**
-     * @see #hit(Ray, Range)
+     * {@return the value <code>t</code> such that <code>ray.at(t)</code> is the intersection of this shaped closest to
-     */
+     * the ray origin, or <code>Double.NaN</code> if the ray does not intersect this shape}
-    default @NotNull Optional<HitResult> hit(@NotNull Ray ray) {
-        return hit(ray, FORWARD);
-    }
-
-    /**
-     * Tests whether the {@code ray} intersects {@code this} hittable.
-     * <p>
-     * The second parameter {@code range} allows the implementation to skip unnecessary calculations if it can
-     * determine that a hit (if any) will fall outside the valid range of {@code t}s. The returned hit may still be
-     * outside the valid range and has to be checked by the caller.
      * @param ray a ray
-     * @param range the range of valid {@code t}s
-     * @return the result of the hit test, containing (among others) the value {@code t} such that {@code ray.at(t)} is
-     *         a point on {@code this} hittable
      */
     @NotNull Optional<HitResult> hit(@NotNull Ray ray, @NotNull Range range);
 
-    /**
-     * {@return the axis-aligned bounding box of this hittable}
-     */
     @NotNull AABB getBoundingBox();
 
     default @NotNull Hittable translate(@NotNull Vec3 offset) {
-        return Translate.create(this, offset);
+        return new Translate(this, offset);
     }
 
     default @NotNull Hittable rotateY(double angle) {
-        return RotateY.create(this, angle);
+        return new RotateY(this, angle);
     }
 }

src/main/java/eu/jonahbauer/raytracing/scene/Scene.java

@@ -2,13 +2,11 @@ package eu.jonahbauer.raytracing.scene;
 
 import eu.jonahbauer.raytracing.math.AABB;
 import eu.jonahbauer.raytracing.math.Ray;
-import eu.jonahbauer.raytracing.render.texture.Color;
+import eu.jonahbauer.raytracing.render.Color;
 import eu.jonahbauer.raytracing.scene.util.HittableBinaryTree;
 import eu.jonahbauer.raytracing.scene.util.HittableCollection;
 import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
 
-import java.util.ArrayList;
 import java.util.List;
 import java.util.Objects;
 
@@ -16,28 +14,29 @@ public final class Scene extends HittableCollection {
     private final @NotNull HittableCollection objects;
     private final @NotNull SkyBox background;
 
-    private final @Nullable List<@NotNull Target> targets;
-
     public Scene(@NotNull List<? extends @NotNull Hittable> objects) {
-        this(objects, null);
+        this(Color.BLACK, objects);
     }
 
-    public Scene(@NotNull List<? extends @NotNull Hittable> objects, @Nullable List<? extends @NotNull Target> targets) {
+    public Scene(@NotNull Color background, @NotNull List<? extends @NotNull Hittable> objects) {
-        this(Color.BLACK, objects, targets);
+        this(SkyBox.solid(background), objects);
     }
 
     public Scene(@NotNull SkyBox background, @NotNull List<? extends @NotNull Hittable> objects) {
-        this(background, objects, null);
+        this.objects = new HittableBinaryTree(objects);
+        this.background = Objects.requireNonNull(background);
     }
 
-    public Scene(@NotNull SkyBox background, @NotNull List<? extends @NotNull Hittable> objects, @Nullable List<? extends @NotNull Target> targets) {
+    public Scene(@NotNull Hittable @NotNull... objects) {
-        var list = new ArrayList<Hittable>(objects.size() + (targets != null ? targets.size() : 0));
+        this(List.of(objects));
-        list.addAll(objects);
+    }
-        if (targets != null) list.addAll(targets);
-        this.objects = new HittableBinaryTree(list);
-        this.background = Objects.requireNonNull(background);
 
-        this.targets = targets != null ? List.copyOf(targets) : null;
+    public Scene(@NotNull Color background, @NotNull Hittable @NotNull... objects) {
+        this(background, List.of(objects));
+    }
+
+    public Scene(@NotNull SkyBox background, @NotNull Hittable @NotNull... objects) {
+        this(background, List.of(objects));
     }
 
     @Override
@@ -50,10 +49,6 @@ public final class Scene extends HittableCollection {
         return objects.getBoundingBox();
     }
 
-    public @Nullable List<@NotNull Target> getTargets() {
-        return targets;
-    }
-
     public @NotNull Color getBackgroundColor(@NotNull Ray ray) {
         return background.getColor(ray);
     }

src/main/java/eu/jonahbauer/raytracing/scene/SkyBox.java

@@ -1,7 +1,7 @@
 package eu.jonahbauer.raytracing.scene;
 
 import eu.jonahbauer.raytracing.math.Ray;
-import eu.jonahbauer.raytracing.render.texture.Color;
+import eu.jonahbauer.raytracing.render.Color;
 import org.jetbrains.annotations.NotNull;
 
 @FunctionalInterface
@@ -18,4 +18,8 @@ public interface SkyBox {
             return Color.lerp(bottom, top, alt / Math.PI + 0.5);
         };
     }
+
+    static @NotNull SkyBox solid(@NotNull Color color) {
+        return _ -> color;
+    }
 }

src/main/java/eu/jonahbauer/raytracing/scene/Target.java

@@ -1,39 +0,0 @@
-package eu.jonahbauer.raytracing.scene;
-
-import eu.jonahbauer.raytracing.math.Vec3;
-import eu.jonahbauer.raytracing.render.renderer.pdf.TargetingProbabilityDensityFunction;
-import org.jetbrains.annotations.NotNull;
-
-import java.util.random.RandomGenerator;
-
-/**
- * An interface for objects that can be targeted. A target can construct randomly distributed directions in which
- * it will be hit from a given origin.
- * @see TargetingProbabilityDensityFunction
- */
-public interface Target extends Hittable {
-    /**
-     * Returns the probability density for a direction as sampled by {@link #getTargetingDirection(Vec3, RandomGenerator)}.
-     * @param origin the origin
-     * @param direction the direction
-     * @return the probability density for a direction as sampled by {@link #getTargetingDirection(Vec3, RandomGenerator)}
-     */
-    double getProbabilityDensity(@NotNull Vec3 origin, @NotNull Vec3 direction);
-
-    /**
-     * {@return a vector targeting this hittable from the <code>origin</code>} The vector is chosen randomly.
-     * @param origin the origin
-     * @param random a random number generator
-     */
-    @NotNull Vec3 getTargetingDirection(@NotNull Vec3 origin, @NotNull RandomGenerator random);
-
-    @Override
-    default @NotNull Target translate(@NotNull Vec3 offset) {
-        return (Target) Hittable.super.translate(offset);
-    }
-
-    @Override
-    default @NotNull Target rotateY(double angle) {
-        return (Target) Hittable.super.rotateY(angle);
-    }
-}

src/main/java/eu/jonahbauer/raytracing/scene/hittable2d/Hittable2D.java

@@ -51,41 +51,8 @@ public abstract class Hittable2D implements Hittable {
         if (!isInterior(alpha, beta)) return Optional.empty();
 
         var frontFace = denominator < 0;
-        return Optional.of(new HitResult(
+        return Optional.of(new HitResult(t, position, frontFace ? normal : normal.neg(), material, frontFace));
-                t, position, frontFace ? normal : normal.neg(), this,
-                material, alpha, beta, frontFace
-        ));
-    }
-
-    protected double hit0(@NotNull Ray ray, @NotNull Range range) {
-        var denominator = ray.direction().times(normal);
-        if (Math.abs(denominator) < 1e-8) return Double.NaN; // parallel
-
-        var t = (d - ray.origin().times(normal)) / denominator;
-        if (!range.surrounds(t)) return Double.NaN;
-
-        var position = ray.at(t);
-        var p = position.minus(origin);
-
-        var alpha = Vec3.tripleProduct(w, p, v);
-        var beta = Vec3.tripleProduct(w, u, p);
-        if (!isInterior(alpha, beta)) return Double.NaN;
-
-        return t;
-    }
-
-    protected @NotNull Vec3 get(double alpha, double beta) {
-        return new Vec3(
-                Math.fma(beta, v.x(), Math.fma(alpha, u.x(), origin.x())),
-                Math.fma(beta, v.y(), Math.fma(alpha, u.y(), origin.y())),
-                Math.fma(beta, v.z(), Math.fma(alpha, u.z(), origin.z()))
-        );
     }
 
     protected abstract boolean isInterior(double alpha, double beta);
-
-    @Override
-    public @NotNull String toString() {
-        return this.getClass().getSimpleName() + "(origin=" + origin + ", u=" + u + ", v=" + v + ")";
-    }
 }

src/main/java/eu/jonahbauer/raytracing/scene/hittable2d/Parallelogram.java

@@ -1,16 +1,11 @@
 package eu.jonahbauer.raytracing.scene.hittable2d;
 
 import eu.jonahbauer.raytracing.math.AABB;
-import eu.jonahbauer.raytracing.math.Ray;
 import eu.jonahbauer.raytracing.math.Vec3;
 import eu.jonahbauer.raytracing.render.material.Material;
-import eu.jonahbauer.raytracing.scene.Target;
-import eu.jonahbauer.raytracing.scene.util.PdfUtil;
 import org.jetbrains.annotations.NotNull;
 
-import java.util.random.RandomGenerator;
+public final class Parallelogram extends Hittable2D {
-
-public final class Parallelogram extends Hittable2D implements Target {
     private final @NotNull AABB bbox;
 
     public Parallelogram(@NotNull Vec3 origin, @NotNull Vec3 u, @NotNull Vec3 v, @NotNull Material material) {
@@ -27,24 +22,4 @@ public final class Parallelogram extends Hittable2D implements Target {
     public @NotNull AABB getBoundingBox() {
         return bbox;
     }
-
-    @Override
-    public double getProbabilityDensity(@NotNull Vec3 origin, @NotNull Vec3 direction) {
-        if (Double.isNaN(hit0(new Ray(origin, direction), FORWARD))) return 0;
-
-        var o = this.origin.minus(origin);
-        var a = o.unit();
-        var b = o.plus(u).unit();
-        var c = o.plus(v).unit();
-        var d = o.plus(u).plus(v).unit();
-        var angle = PdfUtil.getSolidAngle(a, b, d) + PdfUtil.getSolidAngle(c, b, d);
-        return 1 / angle;
-    }
-
-    @Override
-    public @NotNull Vec3 getTargetingDirection(@NotNull Vec3 origin, @NotNull RandomGenerator random) {
-        var alpha = random.nextDouble();
-        var beta = random.nextDouble();
-        return get(alpha, beta).minus(origin);
-    }
 }

src/main/java/eu/jonahbauer/raytracing/scene/hittable3d/Box.java

@@ -1,304 +0,0 @@
-package eu.jonahbauer.raytracing.scene.hittable3d;
-
-import eu.jonahbauer.raytracing.math.AABB;
-import eu.jonahbauer.raytracing.math.Range;
-import eu.jonahbauer.raytracing.math.Ray;
-import eu.jonahbauer.raytracing.math.Vec3;
-import eu.jonahbauer.raytracing.render.material.Material;
-import eu.jonahbauer.raytracing.scene.HitResult;
-import eu.jonahbauer.raytracing.scene.Hittable;
-import eu.jonahbauer.raytracing.scene.Target;
-import eu.jonahbauer.raytracing.scene.util.PdfUtil;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-
-import java.util.Objects;
-import java.util.Optional;
-import java.util.random.RandomGenerator;
-
-public final class Box implements Hittable, Target {
-    private final @NotNull AABB box;
-    private final @Nullable Material @NotNull[] materials;
-
-    public Box(@NotNull Vec3 a, @NotNull Vec3 b, @NotNull Material material) {
-        this(new AABB(a, b), material);
-    }
-
-    public Box(@NotNull AABB box, @NotNull Material material) {
-        this(box, Objects.requireNonNull(material, "material"), material, material, material, material, material);
-    }
-
-    public Box(
-            @NotNull Vec3 a, @NotNull Vec3 b,
-            @Nullable Material top, @Nullable Material bottom,
-            @Nullable Material left, @Nullable Material right,
-            @Nullable Material front, @Nullable Material back
-    ) {
-        this(new AABB(a, b), top, bottom, left, right, front, back);
-    }
-
-    public Box(
-            @NotNull AABB box,
-            @Nullable Material top, @Nullable Material bottom,
-            @Nullable Material left, @Nullable Material right,
-            @Nullable Material front, @Nullable Material back
-    ) {
-        this.box = Objects.requireNonNull(box, "box");
-        this.materials = new Material[] { left, bottom, back, right, top, front };
-    }
-
-    @Override
-    public @NotNull Optional<HitResult> hit(@NotNull Ray ray, @NotNull Range range) {
-        // based on AABB#hit with additional detection of the side hit
-        var origin = ray.origin();
-        var direction = ray.direction();
-        var invDirection = direction.inv();
-
-        var tmin = AABB.intersect(box.min(), origin, invDirection);
-        var tmax = AABB.intersect(box.max(), origin, invDirection);
-
-        double tlmax = Double.NEGATIVE_INFINITY;
-        double tumin = Double.POSITIVE_INFINITY;
-
-        Side entry = null;
-        Side exit = null;
-
-        for (int i = 0; i < 3; i++) {
-            if (direction.get(i) >= 0) {
-                if (tmin[i] > tlmax) {
-                    tlmax = tmin[i];
-                    entry = Side.NEGATIVE[i];
-                }
-                if (tmax[i] < tumin) {
-                    tumin = tmax[i];
-                    exit = Side.POSITIVE[i];
-                }
-            } else {
-                if (tmax[i] > tlmax) {
-                    tlmax = tmax[i];
-                    entry = Side.POSITIVE[i];
-                }
-                if (tmin[i] < tumin) {
-                    tumin = tmin[i];
-                    exit = Side.NEGATIVE[i];
-                }
-            }
-        }
-
-        if (tlmax < tumin && tumin >= range.min() && tlmax <= range.max()) {
-            assert entry != null && exit != null;
-            return hit0(tlmax, tumin, entry, exit, ray, range);
-        } else {
-            return Optional.empty();
-        }
-    }
-
-    private @NotNull Optional<HitResult> hit0(double tmin, double tmax, @NotNull Side entry, @NotNull Side exit, @NotNull Ray ray, @NotNull Range range) {
-        double t;
-        Side side;
-        boolean frontFace;
-        Material material;
-        Vec3 normal;
-        if (range.surrounds(tmin) && materials[entry.ordinal()] != null) {
-            t = tmin;
-            side = entry;
-            frontFace = true;
-            material = materials[side.ordinal()];
-            normal = side.normal;
-        } else if (range.surrounds(tmax) && materials[exit.ordinal()] != null) {
-            t = tmax;
-            side = exit;
-            frontFace = false;
-            material = materials[side.ordinal()];
-            normal = side.normal.neg();
-        } else {
-            return Optional.empty();
-        }
-
-        var position = ray.at(t);
-        var uv = material.texture().isUVRequired();
-        var u = uv ? side.getTextureU(box, position) : Double.NaN;
-        var v = uv ? side.getTextureV(box, position) : Double.NaN;
-        return Optional.of(new HitResult(t, position, normal, this, material, u, v, frontFace));
-    }
-
-    @Override
-    public @NotNull AABB getBoundingBox() {
-        return box;
-    }
-
-    @Override
-    public double getProbabilityDensity(@NotNull Vec3 origin, @NotNull Vec3 direction) {
-        if (contains(origin)) return 1 / (4 * Math.PI);
-        if (hit(new Ray(origin, direction)).isEmpty()) return 0;
-
-        var solidAngle = 0d;
-        for (var s : Side.values()) {
-            if (!s.isExterior(box, origin)) continue;
-            solidAngle += s.getSolidAngle(box, origin);
-        }
-
-        return 1 / solidAngle;
-    }
-
-    @Override
-    public @NotNull Vec3 getTargetingDirection(@NotNull Vec3 origin, @NotNull RandomGenerator random) {
-        if (contains(origin)) return Vec3.random(random);
-
-        // determine sides facing the origin and their solid angles
-        int visible = 0;
-
-        // at most three faces are visible
-        Side[] sides = new Side[3];
-        double[] solidAngle = new double[3];
-
-        double accumSolidAngle = 0;
-        for (var s : Side.values()) {
-            if (!s.isExterior(box, origin)) continue;
-
-            var sa = s.getSolidAngle(box, origin);
-            accumSolidAngle += sa;
-            sides[visible] = s;
-            solidAngle[visible] = accumSolidAngle;
-            visible++;
-        }
-
-        // choose a random side facing the origin based on their relative solid angles
-        var r = random.nextDouble() * solidAngle[visible - 1];
-        for (int j = 0; j < visible; j++) {
-            if (r < solidAngle[j]) {
-                // choose a random point on that side
-                var target = sides[j].random(box, random);
-                return target.minus(origin);
-            }
-        }
-
-        throw new AssertionError();
-    }
-
-    private boolean contains(@NotNull Vec3 point) {
-        return box.min().x() < point.x() && point.x() < box.max().x()
-               && box.min().y() < point.y() && point.y() < box.max().y()
-               && box.min().z() < point.z() && point.z() < box.max().z();
-    }
-
-    @Override
-    public @NotNull String toString() {
-        return "Box(min=" + box.min() + ", max=" + box.max() + ")";
-    }
-
-    private enum Side {
-        NEG_X(Vec3.UNIT_X.neg()),
-        NEG_Y(Vec3.UNIT_Y.neg()),
-        NEG_Z(Vec3.UNIT_Z.neg()),
-        POS_X(Vec3.UNIT_X),
-        POS_Y(Vec3.UNIT_Y),
-        POS_Z(Vec3.UNIT_Z),
-        ;
-
-        private static final Side[] NEGATIVE = new Side[] {Side.NEG_X, Side.NEG_Y, Side.NEG_Z};
-        private static final Side[] POSITIVE = new Side[] {Side.POS_X, Side.POS_Y, Side.POS_Z};
-
-        private final @NotNull Vec3 normal;
-
-        Side(@NotNull Vec3 normal) {
-            this.normal = Objects.requireNonNull(normal, "normal");
-        }
-
-        /**
-         * {@return the texture u coordinate for a position on this side of the box}
-         */
-        public double getTextureU(@NotNull AABB box, @NotNull Vec3 pos) {
-            return switch (this) {
-                case NEG_X -> (pos.z() - box.min().z()) / (box.max().z() - box.min().z());
-                case POS_X -> (box.max().z() - pos.z()) / (box.max().z() - box.min().z());
-                case NEG_Y, POS_Y, POS_Z -> (pos.x() - box.min().x()) / (box.max().x() - box.min().x());
-                case NEG_Z -> (box.max().x() - pos.x()) / (box.max().x() - box.min().x());
-            };
-        }
-
-        /**
-         * {@return the texture v coordinate for a position on this side of the box}
-         */
-        public double getTextureV(@NotNull AABB box, @NotNull Vec3 pos) {
-            return switch (this) {
-                case NEG_X, POS_X, NEG_Z, POS_Z -> (pos.y() - box.min().y()) / (box.max().y() - box.min().y());
-                case NEG_Y -> (pos.z() - box.min().z()) / (box.max().z() - box.min().z());
-                case POS_Y -> (box.max().z() - pos.z()) / (box.max().z() - box.min().z());
-            };
-        }
-
-        /**
-         * {@return whether the given position is outside of the box only considering <code>this</code> side}
-         */
-        public boolean isExterior(@NotNull AABB box, @NotNull Vec3 pos) {
-            return switch (this) {
-                case NEG_X -> pos.x() < box.min().x();
-                case NEG_Y -> pos.y() < box.min().y();
-                case NEG_Z -> pos.z() < box.min().z();
-                case POS_X -> pos.x() > box.max().x();
-                case POS_Y -> pos.y() > box.max().y();
-                case POS_Z -> pos.z() > box.max().z();
-            };
-        }
-
-        /**
-         * {@return the point on <code>this</code> side of the <code>box</code> with the given <code>u</code>-<code>v</code>-coordinates}
-         */
-        public @NotNull Vec3 get(@NotNull AABB box, double u, double v) {
-            return switch (this) {
-                case NEG_X -> new Vec3(
-                        box.min().x(),
-                        Math.fma(v, box.max().y() - box.min().y(), box.min().y()),
-                        Math.fma(u, box.max().z() - box.min().z(), box.min().z())
-                );
-                case NEG_Y -> new Vec3(
-                        Math.fma(u, box.max().x() - box.min().x(), box.min().x()),
-                        box.min().y(),
-                        Math.fma(v, box.max().z() - box.min().z(), box.min().z())
-                );
-                case NEG_Z -> new Vec3(
-                        Math.fma(u, box.min().x() - box.max().x(), box.max().x()),
-                        Math.fma(v, box.max().y() - box.min().y(), box.min().y()),
-                        box.min().z()
-                );
-                case POS_X -> new Vec3(
-                        box.max().x(),
-                        Math.fma(v, box.max().y() - box.min().y(), box.min().y()),
-                        Math.fma(u, box.min().z() - box.max().z(), box.max().z())
-                );
-                case POS_Y -> new Vec3(
-                        Math.fma(u, box.max().x() - box.min().x(), box.min().x()),
-                        box.max().y(),
-                        Math.fma(v, box.min().z() - box.max().z(), box.max().z())
-                );
-                case POS_Z -> new Vec3(
-                        Math.fma(u, box.max().x() - box.min().x(), box.min().x()),
-                        Math.fma(v, box.max().y() - box.min().y(), box.min().y()),
-                        box.max().z()
-                );
-            };
-        }
-
-        /**
-         * {@return a random point on <code>this</code> side of the <code>box</code>}
-         */
-        public @NotNull Vec3 random(@NotNull AABB box, @NotNull RandomGenerator random) {
-            var u = random.nextDouble();
-            var v = random.nextDouble();
-            return get(box, u, v);
-        }
-
-        /**
-         * {@return the solid angle covered by <code>this</code> side of the <code>box</code> when viewed from <code>pos</code>}
-         */
-        public double getSolidAngle(@NotNull AABB box, @NotNull Vec3 pos) {
-            var a = get(box, 0, 0).minus(pos).unit();
-            var b = get(box, 0, 1).minus(pos).unit();
-            var c = get(box, 1, 1).minus(pos).unit();
-            var d = get(box, 1, 0).minus(pos).unit();
-
-            return PdfUtil.getSolidAngle(a, b, d) + PdfUtil.getSolidAngle(c, b, d);
-        }
-    }
-}

src/main/java/eu/jonahbauer/raytracing/scene/hittable3d/ConstantMedium.java

@@ -32,7 +32,7 @@ public record ConstantMedium(@NotNull Hittable boundary, double density, @NotNul
         if (hitDistance > distance) return Optional.empty();
 
         var t = tmin + hitDistance / length;
-        return Optional.of(new HitResult(t, ray.at(t), Vec3.UNIT_X, this, material, 0, 0, true)); // arbitrary normal, u, v and isFrontFace
+        return Optional.of(new HitResult(t, ray.at(t), Vec3.UNIT_X, material, true)); // arbitrary normal and frontFace
     }
 
     @Override

src/main/java/eu/jonahbauer/raytracing/scene/hittable3d/Sphere.java

@@ -7,32 +7,24 @@ import eu.jonahbauer.raytracing.math.Ray;
 import eu.jonahbauer.raytracing.math.Vec3;
 import eu.jonahbauer.raytracing.scene.HitResult;
 import eu.jonahbauer.raytracing.scene.Hittable;
-import eu.jonahbauer.raytracing.scene.Target;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.Objects;
 import java.util.Optional;
-import java.util.random.RandomGenerator;
 
-public final class Sphere implements Hittable, Target {
+public final class Sphere implements Hittable {
     private final @NotNull Vec3 center;
     private final double radius;
     private final @NotNull Material material;
 
     private final @NotNull AABB bbox;
 
-    private final @NotNull Vec3 normalizedCenter;
-    private final double invRadius;
-
     public Sphere(@NotNull Vec3 center, double radius, @NotNull Material material) {
         this.center = Objects.requireNonNull(center, "center");
         this.material = Objects.requireNonNull(material, "material");
         if (radius <= 0 || !Double.isFinite(radius)) throw new IllegalArgumentException("radius must be positive");
         this.radius = radius;
 
-        this.invRadius = 1 / radius;
-        this.normalizedCenter = this.center.times(-this.invRadius);
-
         this.bbox = new AABB(
                 center.minus(radius, radius, radius),
                 center.plus(radius, radius, radius)
@@ -41,32 +33,6 @@ public final class Sphere implements Hittable, Target {
 
     @Override
     public @NotNull Optional<HitResult> hit(@NotNull Ray ray, @NotNull Range range) {
-        var t = hit0(ray, range);
-        if (Double.isNaN(t)) return Optional.empty();
-
-        var position = ray.at(t);
-        var normal = Vec3.fma(invRadius, position, normalizedCenter);
-        var frontFace = normal.times(ray.direction()) < 0;
-
-        double u;
-        double v;
-        if (material.texture().isUVRequired()) {
-            var theta = Math.acos(-normal.y());
-            var phi = Math.atan2(-normal.z(), normal.x()) + Math.PI;
-            u = phi / (2 * Math.PI);
-            v = theta / Math.PI;
-        } else {
-            u = Double.NaN;
-            v = Double.NaN;
-        }
-
-        return Optional.of(new HitResult(
-                t, position, frontFace ? normal : normal.neg(), this,
-                material, u, v, frontFace
-        ));
-    }
-
-    private double hit0(@NotNull Ray ray, @NotNull Range range) {
         var oc = ray.origin().minus(center);
 
         var a = ray.direction().squared();
@@ -74,44 +40,22 @@ public final class Sphere implements Hittable, Target {
         var c = oc.squared() - radius * radius;
 
         var discriminant = h * h - a * c;
-        if (discriminant < 0) return Double.NaN;
+        if (discriminant < 0) return Optional.empty();
 
         var sd = Math.sqrt(discriminant);
 
         double t = (- h - sd) / a;
         if (!range.surrounds(t)) t = (- h + sd) / a;
-        if (!range.surrounds(t)) return Double.NaN;
+        if (!range.surrounds(t)) return Optional.empty();
 
-        return t;
+        var position = ray.at(t);
+        var normal = position.minus(center);
+        var frontFace = normal.times(ray.direction()) < 0;
+        return Optional.of(new HitResult(t, position, frontFace ? normal : normal.times(-1), material, frontFace));
     }
 
     @Override
     public @NotNull AABB getBoundingBox() {
         return bbox;
     }
-
-    @Override
-    public double getProbabilityDensity(@NotNull Vec3 origin, @NotNull Vec3 direction) {
-        if (Double.isNaN(hit0(new Ray(origin, direction), FORWARD))) return 0;
-
-        var cos = Math.sqrt(1 - radius * radius / (center.minus(origin).squared()));
-        var solidAngle = 2 * Math.PI * (1 - cos);
-        return 1 / solidAngle;
-    }
-
-    @Override
-    public @NotNull Vec3 getTargetingDirection(@NotNull Vec3 origin, @NotNull RandomGenerator random) {
-        var direction = center.minus(origin);
-        var out = Vec3.randomOppositeHemisphere(random, direction);
-        return new Vec3(
-                Math.fma(radius, out.x(), center.x() - origin.x()),
-                Math.fma(radius, out.y(), center.y() - origin.y()),
-                Math.fma(radius, out.z(), center.z() - origin.z())
-        );
-    }
-
-    @Override
-    public @NotNull String toString() {
-        return "Sphere(center=" + center + ", radius=" + radius + ")";
-    }
 }

src/main/java/eu/jonahbauer/raytracing/scene/transform/RotateY.java

@@ -5,26 +5,15 @@ import eu.jonahbauer.raytracing.math.Ray;
 import eu.jonahbauer.raytracing.math.Vec3;
 import eu.jonahbauer.raytracing.scene.HitResult;
 import eu.jonahbauer.raytracing.scene.Hittable;
-import eu.jonahbauer.raytracing.scene.Target;
 import org.jetbrains.annotations.NotNull;
 
-import java.util.random.RandomGenerator;
+public final class RotateY extends Transform {
-
-public sealed class RotateY extends Transform {
     private final double cos;
     private final double sin;
 
     private final @NotNull AABB bbox;
 
-    public static @NotNull RotateY create(@NotNull Hittable object, double angle) {
+    public RotateY(@NotNull Hittable object, double angle) {
-        if (object instanceof Target) {
-            return new RotateYTarget(object, angle);
-        } else {
-            return new RotateY(object, angle);
-        }
-    }
-
-    private RotateY(@NotNull Hittable object, double angle) {
         super(object);
         this.cos = Math.cos(angle);
         this.sin = Math.sin(angle);
@@ -56,58 +45,45 @@ public sealed class RotateY extends Transform {
     }
 
     @Override
-    protected final @NotNull Ray transform(@NotNull Ray ray) {
+    protected @NotNull Ray transform(@NotNull Ray ray) {
         var origin = ray.origin();
         var direction = ray.direction();
 
-        var newOrigin = transform(origin);
+        var newOrigin = new Vec3(
-        var newDirection = transform(direction);
+                cos * origin.x() - sin * origin.z(),
+                origin.y(),
+                sin * origin.x() + cos * origin.z()
+        );
+        var newDirection = new Vec3(
+                cos * direction.x() - sin * direction.z(),
+                direction.y(),
+                sin * direction.x() + cos * direction.z()
+        );
+
         return new Ray(newOrigin, newDirection);
     }
 
     @Override
-    protected final @NotNull HitResult transform(@NotNull HitResult result) {
+    protected @NotNull HitResult transform(@NotNull HitResult result) {
         var position = result.position();
-        var newPosition = untransform(position);
+        var newPosition = new Vec3(
+                cos * position.x() + sin * position.z(),
+                position.y(),
+                - sin * position.x() + cos * position.z()
+        );
 
         var normal = result.normal();
-        var newNormal = untransform(normal);
+        var newNormal = new Vec3(
+                cos * normal.x() + sin * normal.z(),
+                normal.y(),
+                -sin * normal.x() + cos * normal.z()
+        );
 
-        return result.withPositionAndNormal(newPosition, newNormal);
+        return new HitResult(result.t(), newPosition, newNormal, result.material(), result.frontFace());
-    }
-
-    protected final @NotNull Vec3 transform(@NotNull Vec3 vec) {
-        return new Vec3(cos * vec.x() - sin * vec.z(), vec.y(), sin * vec.x() + cos * vec.z());
-    }
-
-    protected final @NotNull Vec3 untransform(@NotNull Vec3 vec) {
-        return new Vec3(cos * vec.x() + sin * vec.z(), vec.y(), - sin * vec.x() + cos * vec.z());
     }
 
     @Override
     public @NotNull AABB getBoundingBox() {
         return bbox;
     }
-
-    @Override
-    public @NotNull String toString() {
-        return object + " rotated by " + Math.toDegrees(Math.atan2(sin, cos)) + "° around the y axis";
-    }
-
-    private static final class RotateYTarget extends RotateY implements Target {
-
-        private RotateYTarget(@NotNull Hittable object, double angle) {
-            super(object, angle);
-        }
-
-        @Override
-        public double getProbabilityDensity(@NotNull Vec3 origin, @NotNull Vec3 direction) {
-            return ((Target) object).getProbabilityDensity(transform(origin), transform(direction));
-        }
-
-        @Override
-        public @NotNull Vec3 getTargetingDirection(@NotNull Vec3 origin, @NotNull RandomGenerator random) {
-            return untransform(((Target) object).getTargetingDirection(transform(origin), random));
-        }
-    }
 }

src/main/java/eu/jonahbauer/raytracing/scene/transform/Transform.java

@@ -2,15 +2,12 @@ package eu.jonahbauer.raytracing.scene.transform;
 
 import eu.jonahbauer.raytracing.math.Range;
 import eu.jonahbauer.raytracing.math.Ray;
-import eu.jonahbauer.raytracing.math.Vec3;
 import eu.jonahbauer.raytracing.scene.HitResult;
 import eu.jonahbauer.raytracing.scene.Hittable;
-import eu.jonahbauer.raytracing.scene.Target;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.Objects;
 import java.util.Optional;
-import java.util.random.RandomGenerator;
 
 public abstract class Transform implements Hittable {
     protected final @NotNull Hittable object;

src/main/java/eu/jonahbauer/raytracing/scene/transform/Translate.java

@@ -5,24 +5,13 @@ import eu.jonahbauer.raytracing.math.Ray;
 import eu.jonahbauer.raytracing.math.Vec3;
 import eu.jonahbauer.raytracing.scene.HitResult;
 import eu.jonahbauer.raytracing.scene.Hittable;
-import eu.jonahbauer.raytracing.scene.Target;
 import org.jetbrains.annotations.NotNull;
 
-import java.util.random.RandomGenerator;
+public final class Translate extends Transform {
-
+    private final @NotNull Vec3 offset;
-public sealed class Translate extends Transform {
-    protected final @NotNull Vec3 offset;
     private final @NotNull AABB bbox;
 
-    public static @NotNull Translate create(@NotNull Hittable object, @NotNull Vec3 offset) {
+    public Translate(@NotNull Hittable object, @NotNull Vec3 offset) {
-        if (object instanceof Target) {
-            return new TranslateTarget(object, offset);
-        } else {
-            return new Translate(object, offset);
-        }
-    }
-
-    private Translate(@NotNull Hittable object, @NotNull Vec3 offset) {
         super(object);
         this.offset = offset;
 
@@ -34,40 +23,23 @@ public sealed class Translate extends Transform {
     }
 
     @Override
-    protected final @NotNull Ray transform(@NotNull Ray ray) {
+    protected @NotNull Ray transform(@NotNull Ray ray) {
         return new Ray(ray.origin().minus(offset), ray.direction());
     }
 
     @Override
-    protected final @NotNull HitResult transform(@NotNull HitResult result) {
+    protected @NotNull HitResult transform(@NotNull HitResult result) {
-        return result.withPositionAndNormal(result.position().plus(offset), result.normal());
+        return new HitResult(
+                result.t(),
+                result.position().plus(offset),
+                result.normal(),
+                result.material(),
+                result.frontFace()
+        );
     }
 
     @Override
-    public final @NotNull AABB getBoundingBox() {
+    public @NotNull AABB getBoundingBox() {
         return bbox;
     }
-
-    @Override
-    public @NotNull String toString() {
-        return object + " translated by " + offset;
-    }
-
-    private static final class TranslateTarget extends Translate implements Target {
-        private TranslateTarget(@NotNull Hittable object, @NotNull Vec3 offset) {
-            super(object, offset);
-        }
-
-        @Override
-        public double getProbabilityDensity(@NotNull Vec3 origin, @NotNull Vec3 direction) {
-            if (!(object instanceof Target target)) throw new UnsupportedOperationException();
-            return target.getProbabilityDensity(origin.minus(offset), direction);
-        }
-
-        @Override
-        public @NotNull Vec3 getTargetingDirection(@NotNull Vec3 origin, @NotNull RandomGenerator random) {
-            if (!(object instanceof Target target)) throw new UnsupportedOperationException();
-            return target.getTargetingDirection(origin.minus(offset), random);
-        }
-    }
 }

src/main/java/eu/jonahbauer/raytracing/scene/util/HittableBinaryTree.java

@@ -47,7 +47,7 @@ public final class HittableBinaryTree extends HittableCollection {
 
     @Override
     public void hit(@NotNull Ray ray, @NotNull State state) {
-        if (!bbox.hit(ray, state.getRange())) return;
+        if (!bbox.hit(ray)) return;
         if (left instanceof HittableCollection coll) {
             coll.hit(ray, state);
         } else if (left != null) {

src/main/java/eu/jonahbauer/raytracing/scene/util/HittableCollection.java

@@ -41,10 +41,6 @@ public abstract class HittableCollection implements Hittable {
             this.range = Objects.requireNonNull(range);
         }
 
-        public @NotNull Range getRange() {
-            return range;
-        }
-
         private @NotNull Optional<HitResult> getResult() {
             return Optional.ofNullable(result);
         }

src/main/java/eu/jonahbauer/raytracing/scene/util/HittableList.java

@@ -5,7 +5,6 @@ import eu.jonahbauer.raytracing.math.Ray;
 import eu.jonahbauer.raytracing.scene.Hittable;
 import org.jetbrains.annotations.NotNull;
 
-import java.util.ArrayList;
 import java.util.List;
 
 public final class HittableList extends HittableCollection {
@@ -13,7 +12,7 @@ public final class HittableList extends HittableCollection {
     private final @NotNull AABB bbox;
 
     public HittableList(@NotNull List<? extends @NotNull Hittable> objects) {
-        this.objects = new ArrayList<>(objects);
+        this.objects = List.copyOf(objects);
         this.bbox = AABB.getBoundingBox(this.objects).orElse(AABB.EMPTY);
     }
 

src/main/java/eu/jonahbauer/raytracing/scene/util/HittableOctree.java

@@ -0,0 +1,253 @@
+package eu.jonahbauer.raytracing.scene.util;
+
+import eu.jonahbauer.raytracing.math.AABB;
+import eu.jonahbauer.raytracing.math.Range;
+import eu.jonahbauer.raytracing.math.Ray;
+import eu.jonahbauer.raytracing.math.Vec3;
+import eu.jonahbauer.raytracing.scene.Hittable;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.*;
+import java.util.function.Predicate;
+import java.util.stream.IntStream;
+
+public final class HittableOctree extends HittableCollection {
+    private static final int LIST_SIZE_LIMIT = 16;
+
+    private final @Nullable Storage storage;
+    private final @NotNull AABB bbox;
+
+    public HittableOctree(@NotNull List<? extends @NotNull Hittable> objects) {
+        bbox = AABB.getBoundingBox(objects).orElse(AABB.EMPTY);
+        storage = newStorage(bbox, objects);
+    }
+
+    private static @NotNull AABB[] getBoundingBoxes(@NotNull AABB aabb, @NotNull Vec3 center) {
+        return new AABB[] {
+                new AABB(new Range(aabb.x().min(), center.x()), new Range(aabb.y().min(), center.y()), new Range(aabb.z().min(), center.z())),
+                new AABB(new Range(center.x(), aabb.x().max()), new Range(aabb.y().min(), center.y()), new Range(aabb.z().min(), center.z())),
+                new AABB(new Range(aabb.x().min(), center.x()), new Range(center.y(), aabb.y().max()), new Range(aabb.z().min(), center.z())),
+                new AABB(new Range(center.x(), aabb.x().max()), new Range(center.y(), aabb.y().max()), new Range(aabb.z().min(), center.z())),
+                new AABB(new Range(aabb.x().min(), center.x()), new Range(aabb.y().min(), center.y()), new Range(center.z(), aabb.z().max())),
+                new AABB(new Range(center.x(), aabb.x().max()), new Range(aabb.y().min(), center.y()), new Range(center.z(), aabb.z().max())),
+                new AABB(new Range(aabb.x().min(), center.x()), new Range(center.y(), aabb.y().max()), new Range(center.z(), aabb.z().max())),
+                new AABB(new Range(center.x(), aabb.x().max()), new Range(center.y(), aabb.y().max()), new Range(center.z(), aabb.z().max())),
+        };
+    }
+
+    private static @Nullable Storage newStorage(@NotNull AABB aabb, @NotNull List<? extends @NotNull Hittable> objects) {
+        if (objects.isEmpty()) return null;
+        if (objects.size() < LIST_SIZE_LIMIT) {
+            return new ListStorage(aabb, objects);
+        } else {
+            var center = aabb.center();
+            var octants = (List<Hittable>[]) new List<?>[8];
+            for (int i = 0; i < 8; i++) octants[i] = new ArrayList<>();
+            var bboxes = getBoundingBoxes(aabb, center);
+            var list = new ArrayList<Hittable>();
+
+            for (var object : objects) {
+                var bbox = object.getBoundingBox();
+                var imin = getOctantIndex(center, bbox.min());
+                var imax = getOctantIndex(center, bbox.max());
+                if (imin == imax) {
+                    octants[imin].add(object);
+                } else {
+                    list.add(object);
+                }
+            }
+
+            return new NodeStorage(aabb, center, list, IntStream.range(0, 8).mapToObj(i -> newStorage(bboxes[i], octants[i])).toArray(Storage[]::new));
+        }
+    }
+
+    @Override
+    public void hit(@NotNull Ray ray, @NotNull State state) {
+        hit(ray, object -> hit(state, ray, object));
+    }
+
+    @Override
+    public @NotNull AABB getBoundingBox() {
+        return bbox;
+    }
+
+    /**
+     * Use HERO algorithms to find all elements that could possibly be hit by the given ray.
+     * @see <a href="https://doi.org/10.1007/978-3-642-76298-7_3">
+     *      Agate, M., Grimsdale, R.L., Lister, P.F. (1991).
+     *      The HERO Algorithm for Ray-Tracing Octrees.
+     *      In: Grimsdale, R.L., Straßer, W. (eds) Advances in Computer Graphics Hardware IV. Eurographic Seminars. Springer, Berlin, Heidelberg.</a>
+     */
+    private void hit(@NotNull Ray ray, @NotNull Predicate<? super Hittable> action) {
+        if (storage != null) storage.hit(ray, action);
+    }
+
+    private static int getOctantIndex(@NotNull Vec3 center, @NotNull Vec3 pos) {
+        return (pos.x() < center.x() ? 0 : 1)
+               | (pos.y() < center.y() ? 0 : 2)
+               | (pos.z() < center.z() ? 0 : 4);
+
+    }
+
+    private abstract static sealed class Storage {
+        protected final @NotNull AABB bbox;
+
+        public Storage(@NotNull AABB bbox) {
+            this.bbox = Objects.requireNonNull(bbox);
+        }
+
+        protected boolean hit(@NotNull Ray ray, @NotNull Predicate<? super Hittable> action) {
+            var range = bbox.intersect(ray);
+            if (range.isEmpty()) return false;
+
+            int vmask = ray.vmask();
+            return hit0(ray, vmask, range.get().min(), range.get().max(), action);
+        }
+
+        protected abstract boolean hit0(@NotNull Ray ray, int vmask, double tmin, double tmax, @NotNull Predicate<? super Hittable> action);
+    }
+
+    private static final class ListStorage extends Storage {
+        private final @NotNull List<Hittable> list;
+
+        public ListStorage(@NotNull AABB bbox, @NotNull List<? extends @NotNull Hittable> entries) {
+            super(bbox);
+            this.list = List.copyOf(entries);
+        }
+
+        @Override
+        protected boolean hit0(@NotNull Ray ray, int vmask, double tmin, double tmax, @NotNull Predicate<? super Hittable> action) {
+            var hit = false;
+            for (Hittable hittable : list) {
+                hit |= action.test(hittable);
+            }
+            return hit;
+        }
+    }
+
+    private static final class NodeStorage extends Storage {
+        private final @Nullable Storage @NotNull[] octants;
+        private final @NotNull Vec3 center;
+        private final int degenerate;
+
+        private final @NotNull List<Hittable> list; // track elements spanning multiple octants separately
+
+        public NodeStorage(@NotNull AABB bbox, @NotNull Vec3 center, @NotNull List<? extends @NotNull Hittable> list, @Nullable Storage @NotNull[] octants) {
+            super(bbox);
+            this.octants = octants;
+            this.center = center;
+
+            this.list = List.copyOf(list);
+
+            int count = 0;
+            int degenerate = 0;
+            for (int i = 0; i < octants.length; i++) {
+                if (octants[i] != null) {
+                    count++;
+                    degenerate = i;
+                }
+            }
+            this.degenerate = count == 1 ? degenerate : -1;
+        }
+
+        @Override
+        protected boolean hit(@NotNull Ray ray, @NotNull Predicate<? super Hittable> action) {
+            if (degenerate >= 0 && list.isEmpty()) {
+                return octants[degenerate].hit(ray, action);
+            } else {
+                return super.hit(ray, action);
+            }
+        }
+
+        @Override
+        protected boolean hit0(@NotNull Ray ray, int vmask, double tmin, double tmax, @NotNull Predicate<? super Hittable> action) {
+            if (tmax < 0) return false;
+
+            // check for hit
+            var hit = false;
+
+            // process entries spanning multiple children
+            for (Hittable object : list) {
+                hit |= action.test(object);
+            }
+
+            // t values for intersection points of ray with planes through center
+            var tmid = AABB.intersect(center, ray);
+            // masks of planes in the order of intersection, e.g. [2, 1, 4] for a ray intersection y = center.y() then x = center.x() then z = center.z()
+            var masklist = calculateMasklist(tmid);
+            // the first child to be hit by the ray assuming a ray with positive x, y and z coordinates
+            var childmask = (tmid[0] < tmin ? 1 : 0)
+                            | (tmid[1] < tmin ? 2 : 0)
+                            | (tmid[2] < tmin ? 4 : 0);
+            // the last child to be hit by the ray assuming a ray with positive x, y and z coordinates
+            var lastmask = (tmid[0] < tmax ? 1 : 0)
+                           | (tmid[1] < tmax ? 2 : 0)
+                           | (tmid[2] < tmax ? 4 : 0);
+
+            var childTmin = tmin;
+
+            int i = 0;
+            while (true) {
+                // use vmask to nullify the assumption of a positive ray made for childmask
+                var child = octants[childmask ^ vmask];
+
+                // calculate t value for exit of child
+                double childTmax;
+                if (childmask == lastmask) {
+                    // last child shares tmax
+                    childTmax = tmax;
+                } else {
+                    // determine next child
+                    while ((masklist[i] & childmask) != 0) {
+                        i++;
+                    }
+                    childmask = childmask | masklist[i];
+                    // tmax of current child is the t value for the intersection with the plane dividing the current and next child
+                    childTmax = tmid[Integer.numberOfTrailingZeros(masklist[i])];
+                }
+
+                // process child
+                var childHit = child != null && child.hit0(ray, vmask, childTmin, childTmax, action);
+                hit |= childHit;
+
+                // break after last child has been processed or a hit has been found
+                if (childTmax == tmax || childHit) break;
+
+                // tmin of next child is tmax of current child
+                childTmin = childTmax;
+            }
+
+            return hit;
+        }
+
+        private static final int[][] MASKLISTS = new int[][] {
+                {1, 2, 4},
+                {1, 4, 2},
+                {4, 1, 2},
+                {2, 1, 4},
+                {2, 4, 1},
+                {4, 2, 1}
+        };
+
+        private static int @NotNull [] calculateMasklist(double @NotNull[] tmid) {
+            if (tmid[0] < tmid[1]) {
+                if (tmid[1] < tmid[2]) {
+                    return MASKLISTS[0]; // {1, 2, 4}
+                } else if (tmid[0] < tmid[2]) {
+                    return MASKLISTS[1]; // {1, 4, 2}
+                } else {
+                    return MASKLISTS[2]; // {4, 1, 2}
+                }
+            } else {
+                if (tmid[0] < tmid[2]) {
+                    return MASKLISTS[3]; // {2, 1, 4}
+                } else if (tmid[1] < tmid[2]) {
+                    return MASKLISTS[4]; // {2, 4, 1}
+                } else {
+                    return MASKLISTS[5]; // {4, 2, 1}
+                }
+            }
+        }
+    }
+}

src/main/java/eu/jonahbauer/raytracing/scene/util/Hittables.java

@@ -0,0 +1,35 @@
+package eu.jonahbauer.raytracing.scene.util;
+
+import eu.jonahbauer.raytracing.math.Vec3;
+import eu.jonahbauer.raytracing.render.material.Material;
+import eu.jonahbauer.raytracing.scene.Hittable;
+import eu.jonahbauer.raytracing.scene.hittable2d.Parallelogram;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.ArrayList;
+
+public final class Hittables {
+    private Hittables() {
+        throw new UnsupportedOperationException();
+    }
+
+    public static @NotNull Hittable box(@NotNull Vec3 a, @NotNull Vec3 b, @NotNull Material material) {
+        var sides = new ArrayList<Hittable>();
+
+        var min = Vec3.min(a, b);
+        var max = Vec3.max(a, b);
+
+        var dx = new Vec3(max.x() - min.x(), 0, 0);
+        var dy = new Vec3(0, max.y() - min.y(), 0);
+        var dz = new Vec3(0, 0, max.z() - min.z());
+
+        sides.add(new Parallelogram(new Vec3(min.x(), min.y(), max.z()), dx, dy, material)); // front
+        sides.add(new Parallelogram(new Vec3(max.x(), min.y(), max.z()), dz.neg(), dy, material)); // right
+        sides.add(new Parallelogram(new Vec3(max.x(), min.y(), min.z()), dx.neg(), dy, material)); // back
+        sides.add(new Parallelogram(new Vec3(min.x(), min.y(), min.z()), dz, dy, material)); // left
+        sides.add(new Parallelogram(new Vec3(min.x(), max.y(), max.z()), dx, dz.neg(), material)); // top
+        sides.add(new Parallelogram(new Vec3(min.x(), min.y(), min.z()), dx, dz, material)); // bottom
+
+        return new HittableList(sides);
+    }
+}

src/main/java/eu/jonahbauer/raytracing/scene/util/PdfUtil.java

@@ -1,19 +0,0 @@
-package eu.jonahbauer.raytracing.scene.util;
-
-import eu.jonahbauer.raytracing.math.Vec3;
-import org.jetbrains.annotations.NotNull;
-
-public final class PdfUtil {
-    private PdfUtil() {
-        throw new UnsupportedOperationException();
-    }
-
-    /**
-     * {@return the solid angle of the triangle abc as seen from the origin} The vectors {@code a}, {@code b} and {@code c}
-     * must be unit vectors.
-     */
-    public static double getSolidAngle(@NotNull Vec3 a, @NotNull Vec3 b, @NotNull Vec3 c) {
-        var angle = 2 * Math.atan(Math.abs(Vec3.tripleProduct(a, b, c)) / (1 + a.times(b) + b.times(c) + c.times(a)));
-        return angle < 0 ? 2 * Math.PI + angle : angle;
-    }
-}

src/test/java/eu/jonahbauer/raytracing/render/canvas/ImageTest.java

@@ -1,6 +1,6 @@
 package eu.jonahbauer.raytracing.render.canvas;
 
-import eu.jonahbauer.raytracing.render.texture.Color;
+import eu.jonahbauer.raytracing.render.Color;
 import eu.jonahbauer.raytracing.render.ImageFormat;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;

src/test/java/eu/jonahbauer/raytracing/scene/hittable3d/SphereTest.java

@@ -3,7 +3,7 @@ package eu.jonahbauer.raytracing.scene.hittable3d;
 import eu.jonahbauer.raytracing.math.Range;
 import eu.jonahbauer.raytracing.math.Ray;
 import eu.jonahbauer.raytracing.math.Vec3;
-import eu.jonahbauer.raytracing.render.texture.Color;
+import eu.jonahbauer.raytracing.render.Color;
 import eu.jonahbauer.raytracing.render.material.LambertianMaterial;
 import org.junit.jupiter.api.Test;