Create proper demonstration scene of the spectrum effect

.idea/libraries/google_guava.xml

@@ -2,13 +2,13 @@
   <library name="google.guava" type="repository">
     <properties maven-id="com.google.guava:guava:RELEASE" />
     <CLASSES>
-      <root url="jar://$PROJECT_DIR$/lib/guava-31.1-jre.jar!/" />
+      <root url="jar://$PROJECT_DIR$/lib/guava-32.1.2-jre.jar!/" />
       <root url="jar://$PROJECT_DIR$/lib/failureaccess-1.0.1.jar!/" />
       <root url="jar://$PROJECT_DIR$/lib/listenablefuture-9999.0-empty-to-avoid-conflict-with-guava.jar!/" />
       <root url="jar://$PROJECT_DIR$/lib/jsr305-3.0.2.jar!/" />
-      <root url="jar://$PROJECT_DIR$/lib/checker-qual-3.12.0.jar!/" />
-      <root url="jar://$PROJECT_DIR$/lib/error_prone_annotations-2.11.0.jar!/" />
-      <root url="jar://$PROJECT_DIR$/lib/j2objc-annotations-1.3.jar!/" />
+      <root url="jar://$PROJECT_DIR$/lib/checker-qual-3.33.0.jar!/" />
+      <root url="jar://$PROJECT_DIR$/lib/error_prone_annotations-2.18.0.jar!/" />
+      <root url="jar://$PROJECT_DIR$/lib/j2objc-annotations-2.8.jar!/" />
     </CLASSES>
     <JAVADOC />
     <SOURCES />

.idea/misc.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_19" default="true" project-jdk-name="liberica-19" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_20" default="true" project-jdk-name="liberica-20" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/out" />
   </component>
 </project>

.idea/scopes/Raytracing.xml

@@ -0,0 +1,3 @@
+<component name="DependencyValidationManager">
+  <scope name="Raytracing" pattern="(!lib:*..*&amp;&amp;!test:*..*&amp;&amp;!src:*..*&amp;&amp;!file[GfxLab]:*/&amp;&amp;!ext:*/||src:xyz.marsavic.gfxlab.graphics3d..*||src:xyz.marsavic.gfxlab.playground..*)&amp;&amp;!src:xyz.marsavic.gfxlab.playground.colorfunctions..*" />
+</component>

.idea/vcs.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$" vcs="Git" />
+  </component>
+</project>

README.md

@@ -9,6 +9,7 @@
     - Ako koristite IntelliJ, ovo je lako namestiti: File > Project Structure... > Project > SDK > Add SDK > Download JDK... > Vendor: BellSoft Liberica JDK 19.0.1.
     - Alternativno, sami preuzmite JDK sa [https://bell-sw.com/pages/downloads/](https://bell-sw.com/pages/downloads/#/java-19-current). Izaberite vaš OS, poslednju verziju, i Full JDK (jedino Full JDK uključuje JavaFX). Kada instalirate/raspakujete JDK, namestite u IDE-u da projekat koristi baš taj JDK.
   - Ako nećete da koristite BellSoft Liberica JDK, snađite se da preuzmete odgovarajuće biblioteke na neki način (direktni download svih potrebnih jar-fajlova, Maven, ...). Potrebni su vam javafx-base, javafx-controls, javafx-graphics, i javafx-swing.
+  - U nekim slučajevima JavaFX neće koristiti GPU za iscrtavanje interfejsa i sve će biti pomalo laggy (meni se to dešava uz Linux i integrisani GPU). U tom slučaju (a ni inače verovatno ne može da škodi), dodajte system property `prism.forceGPU = true`, npr. kroz VM argument `-Dprism.forceGPU=true`.
   
 
 ## Šta-gde

src/xyz/marsavic/gfxlab/Color.java

@@ -56,7 +56,7 @@ public class Color {
 			default -> null;
 		};
 	}
-	
+
 	
 	public static Color hsb(Vec3 v) {
 		return hsb(v.x(), v.y(), v.z());
@@ -75,7 +75,7 @@ public class Color {
 		double cr =  4.0767245293f * cl - 3.3072168827f * cm + 0.2307590544f * cs;
 		double cg = -1.2681437731f * cl + 2.6093323231f * cm - 0.3411344290f * cs;
 		double cb = -0.0041119885f * cl - 0.7034763098f * cm + 1.7068625689f * cs;
-		
+
 		return
 			(
 				cr < 0 || cr > 1 ||
@@ -103,7 +103,24 @@ public class Color {
 	public static Color oklabPolar(Vec3 v) {
 		return oklabPolar(v.x(), v.y(), v.z());
 	}
-	
+
+	static double clipDoubleXyz(double x) {
+		if (x < 0.0)
+			return 0.0;
+		return x;
+	}
+
+	public static Color xyz(double x, double y, double z) {
+		double r =  3.2404542 * x - 1.5371385 * y - 0.4985314 * z;
+		double g = -0.9692660 * x + 1.8760108 * y + 0.0415560 * z;
+		double b =  0.0556434 * x - 0.2040259 * y + 1.0572252 * z;
+
+		r = clipDoubleXyz(r);
+		g = clipDoubleXyz(g);
+		b = clipDoubleXyz(b);
+
+		return Color.rgb(r,g,b);
+	}
 	
 	public static Color code(int code) {
 		return rgb(

src/xyz/marsavic/gfxlab/Spectrum.java

@@ -0,0 +1,14 @@
+package xyz.marsavic.gfxlab;
+
+import javafx.util.Pair;
+import java.util.Arrays;
+import java.util.Comparator;
+
+@FunctionalInterface
+public interface Spectrum {
+    public double at(double wavelength);
+
+    public final Spectrum WHITE = w -> 1.0;
+    public final Spectrum BLACK = w -> 0.0;
+}
+

src/xyz/marsavic/gfxlab/SplineSpectrum.java

@@ -0,0 +1,85 @@
+package xyz.marsavic.gfxlab;
+
+import javafx.util.Pair;
+
+import java.util.Arrays;
+import java.util.Comparator;
+
+public class SplineSpectrum implements Spectrum {
+    Pair<Double, Double>[] samples;
+    double[] m;
+
+    public SplineSpectrum(Pair<Double, Double>[] samples) {
+        if (samples == null) {
+            throw new NullPointerException();
+        }
+        this.samples = samples;
+        int n = samples.length;
+
+        double[] d = new double[n - 1];
+        m = new double[n];
+
+
+        for (int i = 1; i < samples.length; i++) {
+            double h = samples[i].getKey() - samples[i - 1].getKey();
+            if (h <= 0.0)
+                throw new IllegalArgumentException("Samples must have strictly increasing x coordinates.");
+            d[i - 1] = (samples[i].getValue() - samples[i - 1].getValue());
+        }
+
+        m[0] = d[0];
+        for (int i = 1; i < n - 1; i++) {
+            if (d[i] == 0.0) {
+                m[i] = 0.0;
+                m[i + 1] = 0.0;
+            } else {
+                double a = m[i] / d[i];
+                double b = m[i + 1] / d[i];
+                double h = a*a+b*b;
+                if (h > 9.0) {
+                    double t = 3.0 / h;
+                    m[i] = t * a * d[i];
+                    m[i + 1] = t * b * d[i];
+                }
+            }
+        }
+    }
+
+    @Override
+    public double at(double wavelength) {
+        final int n = samples.length;
+
+        if (wavelength <= samples[0].getKey()) {
+            return  samples[0].getValue();
+        }
+        if (wavelength >= samples[n-1].getKey()) {
+            return samples[n-1].getValue();
+        }
+
+        int i = Arrays.binarySearch(samples,
+                new Pair<Double, Double>(Double.valueOf(wavelength), null),
+                new DoublePairKeyComparator());
+        if (i >= 0) {
+            return samples[i].getValue();
+        }
+        i = -(i+2); // Invert negative result and get index of previous element
+        double h = samples[i+1].getKey() - samples[i].getKey();
+        double t = (wavelength - samples[i].getKey()) / h;
+        return (samples[i].getValue() * (1 + 2*t) + h*m[i]*t) * (1 - t) * (1 - t)
+                + (samples[i+1].getValue() * (3 - 2*t) + h * m[i+1] * (t - 1)) * t * t;
+    }
+}
+
+class DoublePairKeyComparator implements Comparator<Pair<Double, Double>> {
+    @Override
+    public int compare(Pair<Double, Double> o1, Pair<Double, Double> o2) {
+        double k1 = o1.getKey(), k2 = o2.getKey();
+        if (k1 > k2)
+            return 1;
+        else if (k1 < k2) {
+            return -1;
+        } else {
+            return 0;
+        }
+    }
+}

src/xyz/marsavic/gfxlab/graphics3d/Camera.java

@@ -0,0 +1,8 @@
+package xyz.marsavic.gfxlab.graphics3d;
+
+import xyz.marsavic.geometry.Vector;
+
+
+public interface Camera {
+	Ray exitingRay(Vector sensorPosition);
+}

src/xyz/marsavic/gfxlab/graphics3d/GeometryUtils.java

@@ -2,8 +2,6 @@ package xyz.marsavic.gfxlab.graphics3d;
 
 
 import xyz.marsavic.gfxlab.Vec3;
-import xyz.marsavic.random.sampling.Sampler;
-import xyz.marsavic.utils.Numeric;
 
 public class GeometryUtils {
 	
@@ -26,4 +24,12 @@ public class GeometryUtils {
 	}
 */
 
+	public static Vec3 reflected(Vec3 n, Vec3 d) {
+		return n.mul(2 * d.dot(n) / n.lengthSquared()).sub(d);
+	}
+	
+	public static Vec3 reflectedN(Vec3 n_, Vec3 d) {
+		return n_.mul(2 * d.dot(n_)).sub(d);
+	}
+	
 }

src/xyz/marsavic/gfxlab/graphics3d/Hit.java

@@ -7,12 +7,18 @@ import xyz.marsavic.gfxlab.Vec3;
 /** Interaction of a ray with a solid.*/
 public interface Hit {
 	
-	/** The time of the hit */
+	/** The time of the hit. */
 	double t();
 	
-	/** The normal at the point of the hit */
+	/** The normal at the hit point. */
 	Vec3 n();
 	
+	/** Surface material at the hit point. */
+	Material material();
+	
+	/** 2D coordinates in the internal coordinate system of the surface. */
+	Vector uv();
+	
 	/** The normalized normal at the point of the hit */
 	default Vec3 n_() {
 		return n().normalized_();

src/xyz/marsavic/gfxlab/graphics3d/Light.java

@@ -0,0 +1,20 @@
+package xyz.marsavic.gfxlab.graphics3d;
+
+import xyz.marsavic.gfxlab.Spectrum;
+import xyz.marsavic.gfxlab.Vec3;
+
+/** Point light. */
+public record Light(
+		Vec3 p,
+		Spectrum s
+) {
+	
+	public static Light ps(Vec3 p, Spectrum s) {
+		return new Light(p, s);
+	}
+	
+	public static Light p(Vec3 p) {
+		return ps(p, wavelength -> 1.0);
+	}
+	
+}

src/xyz/marsavic/gfxlab/graphics3d/Material.java

@@ -0,0 +1,46 @@
+package xyz.marsavic.gfxlab.graphics3d;
+
+import javafx.util.Pair;
+import xyz.marsavic.gfxlab.Color;
+import xyz.marsavic.gfxlab.Spectrum;
+import xyz.marsavic.gfxlab.SplineSpectrum;
+
+public record Material(
+		Spectrum diffuse,
+		Spectrum specular,
+		Spectrum emissive,
+		double shininess,
+		Spectrum reflective,
+		Spectrum refractive,
+		Spectrum refractiveIndex
+
+) {
+	public Material diffuse        (Spectrum diffuse        ) { return new Material(diffuse, specular, emissive, shininess, reflective, refractive, refractiveIndex); }
+	public Material specular       (Spectrum  specular      ) { return new Material(diffuse, specular, emissive, shininess, reflective, refractive, refractiveIndex); }
+	public Material emissive       (Spectrum emissive       ) { return new Material(diffuse, specular, emissive, shininess, reflective, refractive, refractiveIndex); }
+	public Material shininess      (double shininess        ) { return new Material(diffuse, specular, emissive, shininess, reflective, refractive, refractiveIndex); }
+	public Material reflective     (Spectrum  reflective    ) { return new Material(diffuse, specular, emissive, shininess, reflective, refractive, refractiveIndex); }
+	public Material refractive     (Spectrum  refractive    ) { return new Material(diffuse, specular, emissive, shininess, reflective, refractive, refractiveIndex); }
+	public Material refractiveIndex(Spectrum refractiveIndex) { return new Material(diffuse, specular, emissive, shininess, reflective, refractive, refractiveIndex); }
+	// Since refractive index is a function from wavelength to a real number, it can be viewed as a spectrum
+
+	public static final Material BLACK   = new Material(w -> 0, w -> 0, w -> 0, 32, w -> 0, w -> 0, w -> 1.5);
+	
+	public static Material matte (Spectrum s) { return BLACK.diffuse(s); }
+	public static Material matte (double k) { return matte(w -> k); }
+	public static Material matte (        ) { return matte(w -> 1.0); } // TODO: potentially have to replace with D65
+	public static final Material MATTE = matte();
+	
+	public static final Material MIRROR = BLACK.reflective(new SplineSpectrum(new Pair[]{
+		new Pair<Double, Double>(248.0, 0.926),
+		new Pair<Double, Double>(400.0, 0.920),
+		new Pair<Double, Double>(532.0, 0.916),
+		new Pair<Double, Double>(633.0, 0.907),
+		new Pair<Double, Double>(800.0, 0.868)
+	}));
+	public static final Material GLASS = BLACK.refractive(w -> 1.0)
+			.refractiveIndex(w -> 1.6 + (w-400)/(800-400) * (1.55 - 1.6)); /* Made to roughly resemble refractive index
+			                                                                  of BaK4 crown glass*/
+
+	public static Material light (Spectrum s) { return BLACK.emissive(s); }
+}

src/xyz/marsavic/gfxlab/graphics3d/Scene.java

@@ -0,0 +1,39 @@
+package xyz.marsavic.gfxlab.graphics3d;
+
+import xyz.marsavic.gfxlab.Color;
+import xyz.marsavic.gfxlab.Spectrum;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+
+
+public interface Scene {
+	Solid solid();
+	
+	Collection<Light> lights();
+	
+	Spectrum backgroundSpectrum = wavelength -> 0;
+
+
+	class Base implements Scene {
+		
+		protected Solid solid;
+		protected final List<Light> lights = new ArrayList<>();
+		
+		@Override
+		public Solid solid() {
+			return solid;
+		}
+		
+		@Override
+		public Collection<Light> lights() {
+			return lights;
+		}
+		
+		public final Spectrum backgroundSpectrum = wavelength -> 0;
+		
+	}
+	
+	
+}

src/xyz/marsavic/gfxlab/graphics3d/Solid.java

@@ -1,8 +1,5 @@
 package xyz.marsavic.gfxlab.graphics3d;
 
-import java.util.ArrayList;
-import java.util.List;
-
 
 public interface Solid {
 	
@@ -19,4 +16,12 @@ public interface Solid {
 		return firstHit(ray, 0);
 	}
 	
+	
+	default boolean hitBetween(Ray ray, double afterTime, double beforeTime) {
+		Hit hit = firstHit(ray);
+		if (hit == null) return false;
+		double t = hit.t();
+		return (afterTime < t) && (t < beforeTime);
+	}
+	
 }

src/xyz/marsavic/gfxlab/graphics3d/cameras/Orthographic.java

@@ -0,0 +1,14 @@
+package xyz.marsavic.gfxlab.graphics3d.cameras;
+
+import xyz.marsavic.geometry.Vector;
+import xyz.marsavic.gfxlab.Vec3;
+import xyz.marsavic.gfxlab.graphics3d.Camera;
+import xyz.marsavic.gfxlab.graphics3d.Ray;
+
+public class Orthographic implements Camera {
+
+    @Override
+    public Ray exitingRay(Vector p) {
+        return Ray.pd(Vec3.zp(0, p), Vec3.xyz(0, 0, 1));
+    }
+}

src/xyz/marsavic/gfxlab/graphics3d/cameras/Perspective.java

@@ -0,0 +1,23 @@
+package xyz.marsavic.gfxlab.graphics3d.cameras;
+
+import xyz.marsavic.geometry.Vector;
+import xyz.marsavic.gfxlab.Vec3;
+import xyz.marsavic.gfxlab.graphics3d.Camera;
+import xyz.marsavic.gfxlab.graphics3d.Ray;
+import xyz.marsavic.utils.Numeric;
+
+
+public record Perspective(
+	double k
+) implements Camera {
+	
+	public static Perspective fov(double angle) {
+		return new Perspective(Numeric.tanT(angle / 2));
+	}
+
+	
+	@Override
+	public Ray exitingRay(Vector p) {
+		return Ray.pd(Vec3.ZERO, Vec3.zp(1/k, p));
+	}
+}

src/xyz/marsavic/gfxlab/graphics3d/cameras/TransformedCamera.java

@@ -0,0 +1,20 @@
+package xyz.marsavic.gfxlab.graphics3d.cameras;
+
+import xyz.marsavic.geometry.Vector;
+import xyz.marsavic.gfxlab.Transformation;
+import xyz.marsavic.gfxlab.graphics3d.Camera;
+import xyz.marsavic.gfxlab.graphics3d.Ray;
+
+
+public record TransformedCamera (
+		Camera source,
+		Transformation transformation
+) implements Camera {
+	
+	@Override
+	public Ray exitingRay(Vector sensorPosition) {
+		Ray ray = source.exitingRay(sensorPosition);
+		return transformation.at(ray);
+	}
+	
+}

src/xyz/marsavic/gfxlab/graphics3d/raytracers/RayTracer.java

@@ -0,0 +1,31 @@
+package xyz.marsavic.gfxlab.graphics3d.raytracers;
+
+import xyz.marsavic.geometry.Vector;
+import xyz.marsavic.gfxlab.Color;
+import xyz.marsavic.gfxlab.ColorFunctionT;
+import xyz.marsavic.gfxlab.graphics3d.Camera;
+import xyz.marsavic.gfxlab.graphics3d.Ray;
+import xyz.marsavic.gfxlab.graphics3d.Scene;
+
+
+public abstract class RayTracer implements ColorFunctionT {
+	
+	protected final Scene scene;
+	protected final Camera camera;
+
+	
+	public RayTracer(Scene scene, Camera camera) {
+		this.scene = scene;
+		this.camera = camera;
+	}
+	
+	
+	protected abstract Color sample(Ray r);
+	
+	@Override
+	public Color at(double t, Vector p) {
+		Ray ray = camera.exitingRay(p);
+		return sample(ray);
+	}
+	
+}

src/xyz/marsavic/gfxlab/graphics3d/raytracers/RayTracerSimple.java

@@ -0,0 +1,123 @@
+package xyz.marsavic.gfxlab.graphics3d.raytracers;
+
+import xyz.marsavic.geometry.Vec;
+import xyz.marsavic.gfxlab.Color;
+import xyz.marsavic.gfxlab.Vec3;
+import xyz.marsavic.gfxlab.graphics3d.*;
+import xyz.marsavic.random.RNG;
+import xyz.marsavic.utils.Numeric;
+
+public class RayTracerSimple extends RayTracer {
+
+	private static final int spectrumSamples = 20;
+	private static final double minWavelength = 380;
+	private static final double maxWavelength = 780;
+	private static final double EPSILON = 1e-9;
+	private static final int sampleNumber = 4;
+	private static final double stopProbability = 1.0;
+
+	public RayTracerSimple(Scene scene, Camera camera) {
+		super(scene, camera);
+	}
+
+	public static RNG rng = new RNG();
+
+	@Override
+	protected Color sample(Ray ray) {
+		Color result = Color.BLACK;
+		for (int i = 0; i < sampleNumber; i++) {
+			double x = 0.0, y = 0.0, z = 0.0;
+			for (int j = 0; j < spectrumSamples; j++) {
+				double wavelength = minWavelength + (((double) j + rng.nextDouble()) / spectrumSamples) * (maxWavelength - minWavelength);
+				double intensity = sample(ray, wavelength, 7);
+
+				x += intensity * Xyz.x[(int) wavelength];
+				y += intensity * Xyz.y[(int) wavelength];
+				z += intensity * Xyz.z[(int) wavelength];
+			}
+
+			result = result.add(Color.xyz(x, y, z));
+		}
+		return result.div(sampleNumber);
+	}
+
+	protected double sample(Ray ray, double wavelength, int depthRemaining) {
+		double returnFactor = 1.0;
+		if (depthRemaining <= 0) {
+			if (rng.nextDouble(1.0) <= stopProbability) {
+				return 0.0;
+			} else {
+				returnFactor = 1/(1-stopProbability);
+			}
+		}
+		
+		Hit hit = scene.solid().firstHit(ray, EPSILON);
+		if (hit == null) {
+			return scene.backgroundSpectrum.at(wavelength);
+		}
+
+		Vec3 p = ray.at(hit.t());                 // The hit point
+		Vec3 n_ = hit.n_();                       // Normalized normal to the body surface at the hit point
+		Vec3 i = ray.d().inverse();               // Incoming direction
+		double lI = i.length();
+		Vec3 r = GeometryUtils.reflectedN(n_, i); // Reflected ray (i reflected over n)
+		Vec3 r_ = r.div(lI);                      // Reflected ray (i reflected over n)
+
+		Material material = hit.material();
+
+		double lightDiffuse  = 0.0;        // The diffuse contribution of the generated path
+		double lightSpecular = 0.0;        // The specular contribution of the generated path
+		double lightReflected = 0.0;      // The reflective contribution of the generated path
+		double lightRefracted = 0.0;      // The refractive contribution of the generated path
+		double lightEmissive = material.emissive().at(wavelength); // The contribution of the light surface itself
+
+		double result = lightEmissive;
+
+		double diffuse = material.diffuse().at(wavelength);
+		if (diffuse != 0.0) {
+			double r1 = rng.nextDouble(1.0); // Angle of projected random vector in the plain normal to n_
+			double r2 = rng.nextDouble(0.25); // Angle of vector compared to n_
+			Vec3 u_ = GeometryUtils.normal(n_).normalized_(); // One of the normalized vectors normal to n
+			Vec3 v_ = n_.cross(u_); // Doesn't need to be normalized because n_ and u_ are normalized and normal
+			Vec3 o = u_.mul(Numeric.sinT(r1)).add(v_.mul(Numeric.cosT(r1)))
+					.mul(Numeric.cosT(r2)).add(n_.mul(Numeric.sinT(r2))); // Outgoing sample vector
+			lightDiffuse = diffuse * sample(Ray.pd(p, o), wavelength, depthRemaining - 1);
+		}
+
+		result += lightDiffuse;
+		double reflective = material.reflective().at(wavelength);
+		if (reflective != 0.0) {
+			lightReflected = sample(Ray.pd(p, r), wavelength, depthRemaining - 1);
+			result += reflective * lightReflected;
+		}
+
+		double refractive = material.refractive().at(wavelength);
+		if (refractive != 0.0) {
+			Vec3 b; // refracted light vector
+			double rInd = 1/material.refractiveIndex().at(wavelength);
+
+			double iCosN = i.dot(n_);
+			if (iCosN < 0) {
+				rInd = 1/rInd;
+			}
+			Vec3 iProjection = n_.mul(iCosN);
+			Vec3 iRejection = i.sub(iProjection);
+			double iSinSqr = iRejection.lengthSquared()/i.lengthSquared();
+			double bSinSqr = iSinSqr*rInd*rInd;
+			if (bSinSqr > 1) {
+				b = r;
+			} else {
+				Vec3 bRejection = iRejection.inverse();
+				Vec3 bProjection = n_.mul(Math.sqrt(bRejection.lengthSquared()*(1-bSinSqr)/bSinSqr));
+				if (iCosN > 0) {
+					bProjection = bProjection.inverse();
+				}
+				b = bRejection.add(bProjection);
+			}
+			lightRefracted = sample(Ray.pd(p, b), wavelength, depthRemaining - 1);
+			result += refractive * lightRefracted;
+		}
+
+		return returnFactor * result;
+	}
+}

src/xyz/marsavic/gfxlab/graphics3d/raytracers/RayTracingTest.java

@@ -1,30 +0,0 @@
-package xyz.marsavic.gfxlab.graphics3d.raytracers;
-
-import xyz.marsavic.geometry.Vector;
-import xyz.marsavic.gfxlab.Color;
-import xyz.marsavic.gfxlab.ColorFunctionT;
-import xyz.marsavic.gfxlab.Vec3;
-import xyz.marsavic.gfxlab.graphics3d.Hit;
-import xyz.marsavic.gfxlab.graphics3d.Ray;
-import xyz.marsavic.gfxlab.graphics3d.solids.Ball;
-import xyz.marsavic.gfxlab.graphics3d.solids.HalfSpace;
-
-
-public class RayTracingTest implements ColorFunctionT {
-
-	Ball ball = Ball.cr(Vec3.xyz(0, 0, 2), 1);
-	HalfSpace halfSpace = HalfSpace.pn(Vec3.xyz(0, -1, 0), Vec3.xyz(0, 1, 0));
-	
-	@Override
-	public Color at(double t, Vector p) {
-		Ray ray = Ray.pq(Vec3.ZERO, Vec3.zp(1, p));
-		
-		Hit hit1 = ball.firstHit(ray);
-		Hit hit2 = halfSpace.firstHit(ray);
-		
-		double tMin = Math.min(Hit.t(hit1), Hit.t(hit2));
-		
-		return Color.gray(1.0 / (1.0 + tMin));
-	}
-	
-}

src/xyz/marsavic/gfxlab/graphics3d/scene/DiscoRoom.java

@@ -0,0 +1,61 @@
+/*
+package xyz.marsavic.gfxlab.graphics3d.scene;
+
+
+import xyz.marsavic.gfxlab.Color;
+import xyz.marsavic.gfxlab.Vec3;
+import xyz.marsavic.gfxlab.graphics3d.Light;
+import xyz.marsavic.gfxlab.graphics3d.Material;
+import xyz.marsavic.gfxlab.graphics3d.Scene;
+import xyz.marsavic.gfxlab.graphics3d.Solid;
+import xyz.marsavic.gfxlab.graphics3d.solids.Ball;
+import xyz.marsavic.gfxlab.graphics3d.solids.Group;
+import xyz.marsavic.gfxlab.graphics3d.solids.HalfSpace;
+import xyz.marsavic.gfxlab.graphics3d.textures.Grid;
+import xyz.marsavic.random.RNG;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+
+
+public class DiscoRoom extends Scene.Base {
+	
+	public DiscoRoom(int nBalls, int nLights, long seed) {
+		RNG rngBalls  = new RNG(2*seed);
+		
+		var materialUVWalls = Grid.standard(Color.WHITE);
+		
+		Collection<Solid> solids = new ArrayList<>();
+		Collections.addAll(solids,
+				HalfSpace.pn(Vec3.xyz(-1,  0,  0), Vec3.xyz( 1,  0,  0), materialUVWalls),
+				HalfSpace.pn(Vec3.xyz( 1,  0,  0), Vec3.xyz(-1,  0,  0), materialUVWalls),
+				HalfSpace.pn(Vec3.xyz( 0, -1,  0), Vec3.xyz( 0,  1,  0), materialUVWalls),
+				HalfSpace.pn(Vec3.xyz( 0,  1,  0), Vec3.xyz( 0, -1,  0), materialUVWalls),
+				HalfSpace.pn(Vec3.xyz( 0,  0,  1), Vec3.xyz( 0,  0, -1), materialUVWalls)
+		);
+		
+		for (int i = 0; i < nBalls; i++) {
+			double hue = rngBalls.nextDouble();
+			Material material = rngBalls.nextDouble() < 0.8 ?
+					Material.matte(Color.hsb(hue, 0.9, 0.9)).specular(Color.WHITE).shininess(16) :
+					Material.MIRROR;
+			
+			solids.add(Ball.cr(Vec3.random(rngBalls).ZOtoMP(), 0.2, uv -> material));
+		}
+		
+		solid = Group.of(solids);
+		
+		
+		RNG rngLights = new RNG(2*seed + 1);
+		
+		for (int i = 0; i < nLights; i++) {
+			lights.add(Light.pc(
+					Vec3.random(rngLights).ZOtoMP(),
+					Color.hsb(rngLights.nextDouble(), 0.75, 1))
+			);
+		}
+	}
+	
+}
+*/

src/xyz/marsavic/gfxlab/graphics3d/scene/Mirrors.java

@@ -0,0 +1,54 @@
+/*
+package xyz.marsavic.gfxlab.graphics3d.scene;
+
+import xyz.marsavic.geometry.Vector;
+import xyz.marsavic.gfxlab.Color;
+import xyz.marsavic.gfxlab.Vec3;
+import xyz.marsavic.gfxlab.graphics3d.Light;
+import xyz.marsavic.gfxlab.graphics3d.Material;
+import xyz.marsavic.gfxlab.graphics3d.Scene;
+import xyz.marsavic.gfxlab.graphics3d.Solid;
+import xyz.marsavic.gfxlab.graphics3d.solids.Ball;
+import xyz.marsavic.gfxlab.graphics3d.solids.Group;
+import xyz.marsavic.gfxlab.graphics3d.solids.HalfSpace;
+import xyz.marsavic.gfxlab.graphics3d.textures.Grid;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+
+
+public class Mirrors extends Scene.Base {
+	
+	public Mirrors(int nBalls) {
+		var materialUVWalls  = Grid.standard(Color.WHITE);
+		var materialUVWallsL = Grid.standard(Color.hsb(0.00, 0.5, 1.0));
+		var materialUVWallsR = Grid.standard(Color.hsb(0.33, 0.5, 1.0));
+		
+		Collection<Solid> solids = new ArrayList<>();
+		Collections.addAll(solids,
+				HalfSpace.pn(Vec3.xyz(-1,  0,  0), Vec3.xyz( 1,  0,  0), materialUVWallsL),
+				HalfSpace.pn(Vec3.xyz( 1,  0,  0), Vec3.xyz(-1,  0,  0), materialUVWallsR),
+				HalfSpace.pn(Vec3.xyz( 0, -1,  0), Vec3.xyz( 0,  1,  0), materialUVWalls),
+				HalfSpace.pn(Vec3.xyz( 0,  1,  0), Vec3.xyz( 0, -1,  0), materialUVWalls),
+				HalfSpace.pn(Vec3.xyz( 0,  0,  1), Vec3.xyz( 0,  0, -1), materialUVWalls)
+		);
+		
+		Collections.addAll(lights,
+				Light.pc(Vec3.xyz(-0.8, 0.8, -0.8), Color.WHITE),
+				Light.pc(Vec3.xyz(-0.8, 0.8,  0.8), Color.WHITE),
+				Light.pc(Vec3.xyz( 0.8, 0.8, -0.8), Color.WHITE),
+				Light.pc(Vec3.xyz( 0.8, 0.8,  0.8), Color.WHITE)
+		);
+		
+		for (int i = 0; i < nBalls; i++) {
+			Vector c = Vector.polar(0.5, 1.0 * i / nBalls);
+			Ball ball = Ball.cr(Vec3.zp(0, c), 0.4, uv -> Material.MIRROR);
+			solids.add(ball);
+		}
+		
+		solid = Group.of(solids);
+	}
+	
+}
+*/

src/xyz/marsavic/gfxlab/graphics3d/scene/RefractionTest.java

@@ -0,0 +1,53 @@
+/*
+package xyz.marsavic.gfxlab.graphics3d.scene;
+
+
+import xyz.marsavic.gfxlab.Color;
+import xyz.marsavic.gfxlab.Vec3;
+import xyz.marsavic.gfxlab.graphics3d.Light;
+import xyz.marsavic.gfxlab.graphics3d.Material;
+import xyz.marsavic.gfxlab.graphics3d.Scene;
+import xyz.marsavic.gfxlab.graphics3d.Solid;
+import xyz.marsavic.gfxlab.graphics3d.solids.Ball;
+import xyz.marsavic.gfxlab.graphics3d.solids.Group;
+import xyz.marsavic.gfxlab.graphics3d.solids.HalfSpace;
+import xyz.marsavic.gfxlab.graphics3d.textures.Grid;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+
+
+public class RefractionTest extends Scene.Base {
+	
+	public RefractionTest() {
+		var materialUVWalls  = Grid.standard(Color.WHITE);
+		var materialUVWallsL = Grid.standard(Color.hsb(0.00, 0.5, 1.0));
+		var materialUVWallsR = Grid.standard(Color.hsb(0.33, 0.5, 1.0));
+		
+		Collection<Solid> solids = new ArrayList<>();
+		Collections.addAll(solids,
+				HalfSpace.pn(Vec3.xyz(-1,  0,  0), Vec3.xyz( 1,  0,  0), materialUVWallsL),
+				HalfSpace.pn(Vec3.xyz( 1,  0,  0), Vec3.xyz(-1,  0,  0), materialUVWallsR),
+				HalfSpace.pn(Vec3.xyz( 0, -1,  0), Vec3.xyz( 0,  1,  0), materialUVWalls),
+				HalfSpace.pn(Vec3.xyz( 0,  1,  0), Vec3.xyz( 0, -1,  0), materialUVWalls),
+				HalfSpace.pn(Vec3.xyz( 0,  0,  1), Vec3.xyz( 0,  0, -1), materialUVWalls),
+				
+				Ball.cr(Vec3.xyz(-0.3,  0.3,  0.0), 0.4, uv -> Material.GLASS.refractive(Color.hsb(0.7, 0.2, 1.0))),
+				Ball.cr(Vec3.xyz( 0.4, -0.4,  0.0), 0.4, uv -> Material.GLASS),
+				Ball.cr(Vec3.xyz(-0.3, -0.4, -0.6), 0.4, uv -> Material.GLASS.refractiveIndex(2.5)),
+				Ball.cr(Vec3.xyz( 0.4,  0.3,  0.6), 0.4, uv -> Material.GLASS.refractiveIndex(0.6))
+		);
+		
+		Collections.addAll(lights,
+				Light.pc(Vec3.xyz(-0.7, 0.7, -0.7), Color.WHITE),
+				Light.pc(Vec3.xyz(-0.7, 0.7,  0.7), Color.WHITE),
+				Light.pc(Vec3.xyz( 0.7, 0.7, -0.7), Color.WHITE),
+				Light.pc(Vec3.xyz( 0.7, 0.7,  0.7), Color.WHITE)
+		);
+		
+		solid = Group.of(solids);
+	}
+	
+}
+*/

src/xyz/marsavic/gfxlab/graphics3d/scene/SceneTest1.java

@@ -0,0 +1,35 @@
+/* package xyz.marsavic.gfxlab.graphics3d.scene;
+
+import xyz.marsavic.gfxlab.Color;
+import xyz.marsavic.gfxlab.Vec3;
+import xyz.marsavic.gfxlab.graphics3d.Light;
+import xyz.marsavic.gfxlab.graphics3d.Material;
+import xyz.marsavic.gfxlab.graphics3d.Scene;
+import xyz.marsavic.gfxlab.graphics3d.solids.Ball;
+import xyz.marsavic.gfxlab.graphics3d.solids.Group;
+import xyz.marsavic.gfxlab.graphics3d.solids.HalfSpace;
+
+import java.util.Collections;
+
+
+public class SceneTest1 extends Scene.Base{
+	
+	public SceneTest1() {
+		solid = Group.of(
+				Ball.cr(Vec3.xyz(0, 0, 0), 1,
+						uv -> Material.matte(Color.hsb(uv.x() * 6, 0.8, uv.y()))
+				),
+				HalfSpace.pn(Vec3.xyz(0, -1, 0), Vec3.xyz(0, 1, 0),
+						uv -> Material.matte(Color.hsb(uv.x(), 0.8, 0.8))
+				)
+		);
+		
+		Collections.addAll(lights,
+				Light.pc(Vec3.xyz(-1, 1, -1), Color.hsb(0.0, 1.0, 0.6)),
+				Light.pc(Vec3.xyz( 2, 0,  0), Color.gray(0.6)),
+				Light.pc(Vec3.xyz( 0, 0,  -2), Color.gray(0.1))
+		);
+	}
+	
+}
+*/

src/xyz/marsavic/gfxlab/graphics3d/scene/SpectrumTest.java

@@ -0,0 +1,75 @@
+package xyz.marsavic.gfxlab.graphics3d.scene;
+
+
+import xyz.marsavic.functions.interfaces.F1;
+import xyz.marsavic.geometry.Vector;
+import xyz.marsavic.gfxlab.SplineSpectrum;
+import xyz.marsavic.gfxlab.Vec3;
+import xyz.marsavic.gfxlab.graphics3d.*;
+import xyz.marsavic.gfxlab.graphics3d.solids.Ball;
+import xyz.marsavic.gfxlab.graphics3d.solids.Group;
+import xyz.marsavic.gfxlab.graphics3d.solids.HalfSpace;
+import xyz.marsavic.gfxlab.graphics3d.solids.Parallelepiped;
+import xyz.marsavic.gfxlab.graphics3d.textures.Grid;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+
+public class SpectrumTest extends Scene.Base {
+
+    public SpectrumTest() {
+        var materialUVWalls  = (F1<Material, Vector>) (uv -> Material.matte(1.0));
+        var materialBlocks = (F1<Material, Vector>) (uv -> Material.matte(0.0));
+        var materialUVWallsL = Grid.standard(w -> 1.0);
+        var materialUVWallsB = Grid.standard(w -> 1.0);
+        var materialCoverBlock = Grid.standard(w -> 0.0);
+
+        var materialUVWallsR = Grid.standard(w -> 1.0);
+
+        var materialGlass = (F1<Material, Vector>) (uv -> Material.GLASS
+                .refractiveIndex(w -> 5.6 + (w-400)/(800-400) * (1.55 - 5.6)));
+        var materialMirror = (F1<Material, Vector>) (uv -> Material.MIRROR);
+
+        var materialLight = (F1<Material, Vector>) (uv -> Material.light(w -> 1.0));
+
+        Collection<Solid> solids = new ArrayList<>();
+        Collections.addAll(solids,
+                HalfSpace.pn(Vec3.xyz(-1,  0,  0), Vec3.xyz( 1,  0,  0), materialUVWallsL),
+                HalfSpace.pn(Vec3.xyz( 1,  0,  0), Vec3.xyz(-1,  0,  0), materialUVWallsR),
+                HalfSpace.pn(Vec3.xyz( 0, -1,  0), Vec3.xyz( 0,  1,  0), materialUVWalls),
+//                HalfSpace.pn(Vec3.xyz( 0,  1,  0), Vec3.xyz( 0, -1,  0), materialUVWalls),
+                HalfSpace.pn(Vec3.xyz( 0,  0,  1), Vec3.xyz( 0,  0, -1), materialUVWallsB),
+                HalfSpace.pn(Vec3.xyz( 0,  0, -6), Vec3.xyz( 0,  0,  1), materialUVWallsB),
+                Ball.cr(Vec3.xyz(0, 6, 0), 0.8, materialLight),
+                Parallelepiped.pabc(Vec3.xyz(-0.25, 0, 0.25),
+                        Vec3.xyz(0.6, 0.8, 0),
+                        Vec3.xyz(-0.2, -0.6, 0),
+                        Vec3.xyz(0, 0, -0.5),
+                        materialGlass),
+
+                Parallelepiped.pabc(Vec3.xyz(-1, 1, 1),
+                        Vec3.xyz(0.75, 0, 0),
+                        Vec3.xyz(0, 0.4, 0),
+                        Vec3.xyz(0, 0, -6),
+                        materialCoverBlock),
+                Parallelepiped.pabc(Vec3.xyz(0.25, 1, 1),
+                        Vec3.xyz(2, 0, 0),
+                        Vec3.xyz(0, 0.4, 0),
+                        Vec3.xyz(0, 0, -6),
+                        materialCoverBlock),
+                Parallelepiped.pabc(Vec3.xyz(-0.25, 1, 1),
+                        Vec3.xyz(0.5, 0, 0),
+                        Vec3.xyz(0, 0.4, 0),
+                        Vec3.xyz(0, 0, -0.75),
+                        materialCoverBlock),
+                Parallelepiped.pabc(Vec3.xyz(-0.25, 1, -0.25),
+                        Vec3.xyz(0.5, 0, 0),
+                        Vec3.xyz(0, 0.4, 0),
+                        Vec3.xyz(0, 0, -6),
+                        materialCoverBlock)
+        );
+
+        solid = Group.of(solids);
+    }
+}

src/xyz/marsavic/gfxlab/graphics3d/solids/Ball.java

@@ -1,8 +1,10 @@
 package xyz.marsavic.gfxlab.graphics3d.solids;
 
+import xyz.marsavic.functions.interfaces.F1;
 import xyz.marsavic.geometry.Vector;
 import xyz.marsavic.gfxlab.Vec3;
 import xyz.marsavic.gfxlab.graphics3d.Hit;
+import xyz.marsavic.gfxlab.graphics3d.Material;
 import xyz.marsavic.gfxlab.graphics3d.Ray;
 import xyz.marsavic.gfxlab.graphics3d.Solid;
 import xyz.marsavic.utils.Numeric;
@@ -12,21 +14,22 @@ public class Ball implements Solid {
 	
 	private final Vec3 c;
 	private final double r;
+	private final F1<Material, Vector> mapMaterial;
 	
 	// transient
 	private final double rSqr;
-
 	
 	
-	private Ball(Vec3 c, double r) {
+	private Ball(Vec3 c, double r, F1<Material, Vector> mapMaterial) {
 		this.c = c;
 		this.r = r;
 		rSqr = r * r;
+		this.mapMaterial = mapMaterial;
 	}
 	
 	
-	public static Ball cr(Vec3 c, double r) {
-		return new Ball(c, r);
+	public static Ball cr(Vec3 c, double r, F1<Material, Vector> mapMaterial) {
+		return new Ball(c, r, mapMaterial);
 	}
 	
 	
@@ -69,6 +72,20 @@ public class Ball implements Solid {
 			return ray().at(t()).sub(c());
 		}
 		
+		@Override
+		public Material material() {
+			return Ball.this.mapMaterial.at(uv());
+		}
+		
+		@Override
+		public Vector uv() {
+			Vec3 n = n();
+			return Vector.xy(
+					Numeric.atan2T(n.z(), n.x()),
+					-2 * Numeric.asinT(n.y() / r) + 0.5
+			);
+		}
+		
 		@Override
 		public Vec3 n_() {
 			return n().div(r);

src/xyz/marsavic/gfxlab/graphics3d/solids/Group.java

@@ -0,0 +1,53 @@
+package xyz.marsavic.gfxlab.graphics3d.solids;
+
+import xyz.marsavic.gfxlab.graphics3d.Hit;
+import xyz.marsavic.gfxlab.graphics3d.Ray;
+import xyz.marsavic.gfxlab.graphics3d.Solid;
+
+import java.util.Collection;
+
+public class Group implements Solid {
+	
+	private final Solid[] solids;
+	
+	
+	private Group(Solid... solids) {
+		this.solids = solids.clone();
+	}
+	
+	public static Group of(Solid... solids) {
+		return new Group(solids);
+	}
+	
+	public static Group of(Collection<Solid> solids) {
+		return new Group(solids.toArray(Solid[]::new));
+	}
+	
+	@Override
+	public Hit firstHit(Ray ray, double afterTime) {
+		double minT = Double.POSITIVE_INFINITY;
+		Hit minHit = null;
+		
+		for (Solid s : solids) {
+			Hit hit = s.firstHit(ray, afterTime);
+			double t = Hit.t(hit);
+			if (t < minT) {
+				minT = t;
+				minHit = hit;
+			}
+		}
+		
+		return minHit;
+	}
+	
+	@Override
+	public boolean hitBetween(Ray ray, double afterTime, double beforeTime) {
+		for (Solid s : solids) {
+			Hit hit = s.firstHit(ray, afterTime);
+			if ((hit != null) && (hit.t() < beforeTime)) {
+				return true;
+			}
+		}
+		return false;
+	}
+}

src/xyz/marsavic/gfxlab/graphics3d/solids/HalfSpace.java

@@ -1,10 +1,9 @@
 package xyz.marsavic.gfxlab.graphics3d.solids;
 
+import xyz.marsavic.functions.interfaces.F1;
+import xyz.marsavic.geometry.Vector;
 import xyz.marsavic.gfxlab.Vec3;
-import xyz.marsavic.gfxlab.graphics3d.GeometryUtils;
-import xyz.marsavic.gfxlab.graphics3d.Hit;
-import xyz.marsavic.gfxlab.graphics3d.Ray;
-import xyz.marsavic.gfxlab.graphics3d.Solid;
+import xyz.marsavic.gfxlab.graphics3d.*;
 
 
 public class HalfSpace implements Solid {
@@ -12,6 +11,7 @@ public class HalfSpace implements Solid {
 	private final Vec3 p; // A point on the boundary plane
 	private final Vec3 e; // A vector parallel to the boundary plane.
 	private final Vec3 f; // A vector parallel to the boundary plane, not parallel to e.
+	private final F1<Material, Vector> mapMaterial;
 	
 	// transient
 	private final Vec3 n; // A normal vector to the boundary plane
@@ -20,10 +20,11 @@ public class HalfSpace implements Solid {
 	
 	
 	
-	private HalfSpace(Vec3 p, Vec3 e, Vec3 f) {
+	private HalfSpace(Vec3 p, Vec3 e, Vec3 f, F1<Material, Vector> mapMaterial) {
 		this.p = p;
 		this.e = e;
 		this.f = f;
+		this.mapMaterial = mapMaterial;
 		this.n = e.cross(f);
 		
 		n_ = n.normalized_();
@@ -37,21 +38,21 @@ public class HalfSpace implements Solid {
 	}
 	
 	
-	public static HalfSpace pef(Vec3 p, Vec3 e, Vec3 f) {
-		return new HalfSpace(p, e, f);
+	public static HalfSpace pef(Vec3 p, Vec3 e, Vec3 f, F1<Material, Vector> mapMaterial) {
+		return new HalfSpace(p, e, f, mapMaterial);
 	}
 	
 	
-	public static HalfSpace pqr(Vec3 p, Vec3 q, Vec3 r) {
-		return pef(p, q.sub(p), r.sub(p));
+	public static HalfSpace pqr(Vec3 p, Vec3 q, Vec3 r, F1<Material, Vector> mapMaterial) {
+		return pef(p, q.sub(p), r.sub(p), mapMaterial);
 	}
 	
 	
-	public static HalfSpace pn(Vec3 p, Vec3 n) {
+	public static HalfSpace pn(Vec3 p, Vec3 n, F1<Material, Vector> mapMaterial) {
 		double nl = n.length();
 		Vec3 e = GeometryUtils.normal(n).normalizedTo(nl);
 		Vec3 f = n.cross(e).normalizedTo(nl);
-		return new HalfSpace(p, e, f);
+		return new HalfSpace(p, e, f, mapMaterial);
 	}
 	
 	
@@ -113,11 +114,30 @@ public class HalfSpace implements Solid {
 			return n;
 		}
 		
+		@Override
+		public Material material() {
+			return HalfSpace.this.mapMaterial.at(uv());
+		}
+		
 		@Override
 		public Vec3 n_() {
 			return n_;
 		}
 		
+		@Override
+		public Vector uv() {
+			Vec3 b = ray().at(t()).sub(p);
+			
+			double b_e = b.dot(e) / eLSqr;
+			double b_f = b.dot(f) / fLSqr;
+			
+			return Vector.xy(
+					(b_e - b_f * f_e) / sinSqr,
+					(b_f - b_e * e_f) / sinSqr
+			);
+		}
 	}
 	
+	
 }
+

src/xyz/marsavic/gfxlab/graphics3d/solids/Parallelepiped.java

@@ -0,0 +1,108 @@
+package xyz.marsavic.gfxlab.graphics3d.solids;
+
+import xyz.marsavic.functions.interfaces.F1;
+import xyz.marsavic.geometry.Vector;
+import xyz.marsavic.gfxlab.Vec3;
+import xyz.marsavic.gfxlab.graphics3d.Hit;
+import xyz.marsavic.gfxlab.graphics3d.Material;
+import xyz.marsavic.gfxlab.graphics3d.Ray;
+import xyz.marsavic.gfxlab.graphics3d.Solid;
+
+public class Parallelepiped implements Solid {
+
+    private final Vec3 p; // starting vertex
+
+    private final Vec3[][][] vertices;
+    HalfSpace [] sides;
+
+    private final Vec3 a, b, c;
+
+    private Parallelepiped(Vec3 point, Vec3 aEdge, Vec3 bEdge, Vec3 cEdge, F1<Material, Vector> mapMaterial) {
+        this.p = point;
+        this.a = aEdge;
+        this.b = bEdge;
+        this.c = cEdge;
+
+        vertices = new Vec3[][][]
+                {{{p,       p.add(c)},        {p.add(b),        p.add(b).add(c)}},
+                {{p.add(a), p.add(a).add(c)}, {p.add(a).add(b), p.add(a).add(b).add(c)}}};
+        sides = new HalfSpace[6];
+        sides[0] = HalfSpace.pef(p, b, a, mapMaterial);
+        sides[1] = HalfSpace.pef(p.add(c), a, b, mapMaterial);
+        sides[2] = HalfSpace.pef(p, a, c, mapMaterial);
+        sides[3] = HalfSpace.pef(p.add(b), c, a, mapMaterial);
+        sides[4] = HalfSpace.pef(p, c, b, mapMaterial);
+        sides[5] = HalfSpace.pef(p.add(a), b, c, mapMaterial);
+    }
+
+
+    public static Parallelepiped pabc(Vec3 p, Vec3 a, Vec3 b, Vec3 c, F1<Material, Vector> mapMaterial) {
+        return new Parallelepiped(p, a, b, c, mapMaterial);
+    }
+
+    public Vec3 p() {
+        return p;
+    }
+
+    public Vec3 a() {
+        return a;
+    }
+
+    public Vec3 b() {
+        return b;
+    }
+
+    public Vec3 c() {
+        return c;
+    }
+
+    public Vec3[][][] vertices() {
+        return vertices.clone();
+    }
+
+    private static boolean pointOnParallelogram(Vec3 p, Vec3 e, Vec3 f) {
+        // we solve p as a linear combination of a*e+b*f, then check if this combination is in
+        // 0<=a<=1 and 0<=b<=1
+        double D = e.lengthSquared() * f.lengthSquared() - e.dot(f)*e.dot(f);
+        if (D == 0)
+            return false;
+        // System determinant
+        double Da = p.dot(e)*f.lengthSquared() - p.dot(f)*e.dot(f);
+        // a's determinant
+        double Db = e.lengthSquared()*p.dot(f) - e.dot(f)*p.dot(e);
+        double a = Da/D;
+        // a's determinant
+        double b = Db/D;
+        // b's determinant
+        return a >= 0 && a <= 1 && b >= 0 && b <= 1;
+    }
+
+
+    @Override
+    public Hit firstHit(Ray ray, double afterTime) {
+        Hit[] planeHits = new Hit[6];
+
+        for (int i = 0; i < 6; i++) {
+            planeHits[i] = sides[i].firstHit(ray, afterTime);
+            if (planeHits[i] == null) {
+                continue;
+            }
+            Vec3 rayPlaneIntersect = ray.at(planeHits[i].t());
+            if (!pointOnParallelogram(rayPlaneIntersect.sub(sides[i].p()), sides[i].e(), sides[i].f())) {
+                planeHits[i] = null;
+            }
+        }
+
+        double minT = Hit.t(null); // Positive infinity
+        int minI = 0;
+        for (int i = 0; i < 6; i++) {
+            if (Hit.t(planeHits[i]) < minT) {
+                minT = Hit.t(planeHits[i]);
+                minI = i;
+            }
+        }
+
+        return planeHits[minI];
+    }
+
+}

src/xyz/marsavic/gfxlab/graphics3d/textures/Grid.java

@@ -0,0 +1,55 @@
+package xyz.marsavic.gfxlab.graphics3d.textures;
+
+
+import xyz.marsavic.functions.interfaces.F1;
+import xyz.marsavic.geometry.Vector;
+import xyz.marsavic.gfxlab.Color;
+import xyz.marsavic.gfxlab.Spectrum;
+import xyz.marsavic.gfxlab.graphics3d.Material;
+
+
+public class Grid implements F1<Material, Vector> {
+	
+	private final Vector size, sizeLine;
+	private final Material material, materialLine;
+	
+	// transient
+	private final Vector sizeLineHalf;
+	
+	
+	
+	public Grid(Vector size, Vector sizeLine, Material material, Material materialLine) {
+		this.size = size;
+		this.sizeLine = sizeLine;
+		this.material = material;
+		this.materialLine = materialLine;
+		sizeLineHalf = sizeLine.div(2);
+	}
+	
+	
+	@Override
+	public Material at(Vector uv) {
+		Vector p = uv.add(sizeLineHalf).mod(size);
+		return (p.x() < sizeLine.x()) || (p.y() < sizeLine.y()) ? materialLine : material;
+	}
+	
+	
+	public static Grid standard(Spectrum spectrum) {
+		return new Grid(
+				Vector.xy(0.25, 0.25),
+				Vector.xy(0.01, 0.01),
+				Material.matte(spectrum),
+				Material.matte(w -> spectrum.at(w) * 0.75)
+		);
+	}
+	
+
+	public static Grid standardUnit(Spectrum spectrum) {
+		return new Grid(
+				Vector.UNIT_DIAGONAL,
+				Vector.xy(1.0/64),
+				Material.matte(spectrum),
+				Material.matte(w -> spectrum.at(w) * 0.75)
+		);
+	}
+}

src/xyz/marsavic/gfxlab/gui/UtilsGL.java

@@ -15,10 +15,9 @@ import xyz.marsavic.gfxlab.Color;
 import xyz.marsavic.gfxlab.Matrix;
 import xyz.marsavic.gfxlab.MatrixData;
 import xyz.marsavic.gfxlab.MatrixInts;
-import xyz.marsavic.resources.ResourceManagerMap;
 import xyz.marsavic.random.RNG;
+import xyz.marsavic.resources.ResourceManagerMap;
 import xyz.marsavic.time.Profiler;
-import xyz.marsavic.utils.Utils;
 
 import javax.imageio.ImageIO;
 import java.io.File;
@@ -139,13 +138,13 @@ public class UtilsGL {
 	static {
 		int p = ForkJoinPool.getCommonPoolParallelism();
 		try {
-			boolean obsRunning = false;
-			obsRunning |= ProcessHandle.allProcesses().anyMatch(ph -> ph.info().command().orElse("").contains("obs64")); // Windows
-			obsRunning |= !Utils.runCommand("top -b -n 1 | grep \" obs\"").isEmpty(); // Linux
-			obsRunning |= true;
-			if (obsRunning) {
-				p -= 3;
-			}
+//			boolean obsRunning = false;
+//			obsRunning |= ProcessHandle.allProcesses().anyMatch(ph -> ph.info().command().orElse("").contains("obs64")); // Windows
+//			obsRunning |= !Utils.runCommand("top -b -n 1 | grep \" obs\"").isEmpty(); // Linux
+//			obsRunning |= true;
+//			if (obsRunning) {
+				p = 1 + p/2;
+//			}
 		} catch (Exception e) {
 			e.printStackTrace();
 		}

src/xyz/marsavic/gfxlab/playground/GfxLab.java

@@ -4,11 +4,15 @@ import xyz.marsavic.functions.interfaces.A2;
 import xyz.marsavic.functions.interfaces.F1;
 import xyz.marsavic.gfxlab.*;
 import xyz.marsavic.gfxlab.elements.Output;
-import xyz.marsavic.gfxlab.graphics3d.raytracers.RayTracingTest;
+import xyz.marsavic.gfxlab.graphics3d.Affine;
+import xyz.marsavic.gfxlab.graphics3d.cameras.Perspective;
+import xyz.marsavic.gfxlab.graphics3d.cameras.TransformedCamera;
+import xyz.marsavic.gfxlab.graphics3d.raytracers.RayTracerSimple;
+import xyz.marsavic.gfxlab.graphics3d.scene.SpectrumTest;
 import xyz.marsavic.gfxlab.gui.UtilsGL;
 import xyz.marsavic.gfxlab.tonemapping.ColorTransform;
 import xyz.marsavic.gfxlab.tonemapping.ToneMapping;
-import xyz.marsavic.gfxlab.tonemapping.colortransforms.Identity;
+import xyz.marsavic.gfxlab.tonemapping.matrixcolor_to_colortransforms.AutoSoft;
 
 import static xyz.marsavic.gfxlab.elements.ElementF.e;
 import static xyz.marsavic.gfxlab.elements.Output.val;
@@ -28,21 +32,33 @@ public class GfxLab {
 								e(Fs::aFillFrameColor,
 										e(Fs::transformedColorFunction,
 //												e(Blobs::new, val(5), val(0.1), val(0.2)),
-												e(RayTracingTest::new),
+												e(RayTracerSimple::new,
+//														e(RefractionTest::new),
+//														e(DiscoRoom::new, val(16), val(16), val(0x3361EB272FEA4C62L)),
+														e(SpectrumTest::new),
+//														e(Mirrors::new, val(3)),
+														e(TransformedCamera::new,
+															e(Perspective::new, val(1.0/3)),
+//															e(Orthographic::new),
+															e(Affine.IDENTITY
+																	.then(Affine.translation(Vec3.xyz(0, 0, -4)))
+															)
+														)
+												),
 												e(TransformationsFromSize.toGeometric, eSize)
 										)
 								),
 								e(Fs::toneMapping,
-										e(ColorTransform::asColorTransformFromMatrixColor,
-												e(Identity::new)
-										)
+//										e(ColorTransform::asColorTransformFromMatrixColor,
+//												e(Multiply::new, val(0.05))
+//										)
+										e(AutoSoft::new, e(0x1p-5), e(1.0))
 								)
 						)
-				);
+		);
 		
 		outRenderer = eRenderer.out();
 	}
-	
 }
 
 
@@ -70,8 +86,9 @@ class Fs {
 	public static ToneMapping toneMapping(F1<ColorTransform, Matrix<Color>> f_ColorTransform_MatrixColor) {
 		return (input, output) -> {
 			ColorTransform f = f_ColorTransform_MatrixColor.at(input);
-			output.fill(p -> f.at(input.get(p)).code());
+			output.fill(p -> f.at(input.get(p)).codeClamp());
 		};
 	}
+
 	
 }

src/xyz/marsavic/gfxlab/tonemapping/matrixcolor_to_colortransforms/AutoSoft.java

@@ -0,0 +1,71 @@
+package xyz.marsavic.gfxlab.tonemapping.matrixcolor_to_colortransforms;
+
+import xyz.marsavic.functions.interfaces.F1;
+import xyz.marsavic.geometry.Vector;
+import xyz.marsavic.gfxlab.Color;
+import xyz.marsavic.gfxlab.Matrix;
+import xyz.marsavic.gfxlab.gui.UtilsGL;
+import xyz.marsavic.gfxlab.tonemapping.ColorTransform;
+
+
+// TODO
+public class AutoSoft implements F1<ColorTransform, Matrix<Color>> {
+	
+	private final double preFactor;
+	private final double power;
+	private final double postFactor = 1.0;
+	private final boolean autoPostFactor = true;
+	
+	
+	public AutoSoft(double preFactor, double power) {
+		this.preFactor = preFactor;
+		this.power = power;
+	}
+	
+	
+	private double lFactor(double lSrc) {
+		double lPre = lSrc * preFactor;
+		double lDst = 1 - 1 / (1 + Math.pow(lPre, power));
+		
+		double f = lDst / lSrc;
+		if (Double.isNaN(f)) {
+			f = 0;
+		}
+		return f;
+	}
+	
+	
+	@Override
+	public ColorTransform at(Matrix<Color> colorMatrix) {
+		Vector size = colorMatrix.size();
+		
+		double postFactor_;
+		
+		if (autoPostFactor) {
+			double[] maxY = new double[size.xInt()];
+			
+			UtilsGL.parallelY(size, y -> {
+				maxY[y] = Double.NEGATIVE_INFINITY;
+				for (int x = 0; x < size.xInt(); x++) {
+					Color c = colorMatrix.get(x, y);
+					Color result = c.mul(lFactor(c.luminance()));
+					maxY[y] = Math.max(maxY[y], result.max());
+				}
+			});
+			
+			// TODO Replace with fork-join task.
+			
+			double max = Double.NEGATIVE_INFINITY;
+			for (int y = 0; y < size.yInt(); y++) {
+				max = Math.max(max, maxY[y]);
+			}
+			
+			postFactor_ = 1 / max;
+		} else {
+			postFactor_ = postFactor;
+		}
+		
+		return color -> color.mul(lFactor(color.luminance()) * postFactor_);
+	}
+	
+}