From 6ca3b84847334c34865a7ed567a811ec4764ed2c Mon Sep 17 00:00:00 2001
From: kappa <petarkapris@firemail.cc>
Date: Tue, 3 Oct 2023 20:13:40 +0200
Subject: [PATCH] Randomize and average sample wavelengths

---
 .../graphics3d/raytracers/RayTracerSimple.java    | 15 ++++++++++++---
 .../gfxlab/graphics3d/scene/SpectrumTest.java     | 14 +++++++-------
 2 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/src/xyz/marsavic/gfxlab/graphics3d/raytracers/RayTracerSimple.java b/src/xyz/marsavic/gfxlab/graphics3d/raytracers/RayTracerSimple.java
index 3d06e4b..e391fce 100644
--- a/src/xyz/marsavic/gfxlab/graphics3d/raytracers/RayTracerSimple.java
+++ b/src/xyz/marsavic/gfxlab/graphics3d/raytracers/RayTracerSimple.java
@@ -3,6 +3,7 @@ package xyz.marsavic.gfxlab.graphics3d.raytracers;
 import xyz.marsavic.gfxlab.Color;
 import xyz.marsavic.gfxlab.Vec3;
 import xyz.marsavic.gfxlab.graphics3d.*;
+import xyz.marsavic.random.RNG;
 
 public class RayTracerSimple extends RayTracer {
 
@@ -14,16 +15,24 @@ public class RayTracerSimple extends RayTracer {
 	public RayTracerSimple(Scene scene, Camera camera) {
 		super(scene, camera);
 	}
-	
+
+	public static RNG rng = new RNG();
+
 	@Override
 	protected Color sample(Ray ray) {
-		return sample(ray, 64);
+		Color s = Color.BLACK;
+		int n = 5;
+		for (int i = 0; i < n; i++) {
+			s = s.add(sample(ray, 64));
+		}
+		return s.div(n);
+
 	}
 
 	protected Color sample(Ray ray, int depthRemaining) {
 		double x = 0.0, y = 0.0, z = 0.0;
 		for (int i = 0; i < spectrumSamples; i++) {
-			double wavelength = minWavelength + (((double) i)/spectrumSamples)*(maxWavelength - minWavelength);
+			double wavelength = minWavelength + (((double) i + rng.nextDouble())/spectrumSamples)*(maxWavelength - minWavelength);
 			double intensity = sample(ray, depthRemaining, wavelength);
 
 			x += intensity * Xyz.x[(int) wavelength];
diff --git a/src/xyz/marsavic/gfxlab/graphics3d/scene/SpectrumTest.java b/src/xyz/marsavic/gfxlab/graphics3d/scene/SpectrumTest.java
index 2cf53ba..f10bfbe 100644
--- a/src/xyz/marsavic/gfxlab/graphics3d/scene/SpectrumTest.java
+++ b/src/xyz/marsavic/gfxlab/graphics3d/scene/SpectrumTest.java
@@ -4,6 +4,7 @@ package xyz.marsavic.gfxlab.graphics3d.scene;
 import javafx.util.Pair;
 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.SplineSpectrum;
 import xyz.marsavic.gfxlab.Vec3;
@@ -32,21 +33,20 @@ public class SpectrumTest extends Scene.Base {
         Collection<Solid> solids = new ArrayList<>();
         Collections.addAll(solids,
                 HalfSpace.pn(Vec3.xyz(1,  0,  10), Vec3.xyz( 1,  0,  -1), materialUVWallsL),
-                HalfSpace.pn(Vec3.xyz( -1,  0,  10), Vec3.xyz(-1,  0,  -1), materialUVWallsR),
+                HalfSpace.pn(Vec3.xyz( 0,  0,  10), Vec3.xyz(-1,  0,  -1), materialUVWallsR),
                 HalfSpace.pn(Vec3.xyz(0,  2,  0), Vec3.xyz( 0,  -1,  0), materialUVWallsL),
                 HalfSpace.pn(Vec3.xyz(0,  -2,  10), Vec3.xyz( 0,  1,  0), materialUVWallsL),
 
-                HalfSpace.pn(Vec3.xyz( 0,  0,  8), Vec3.xyz(0,  1,  -1), uv -> Material.GLASS.refractiveIndex(
-//                        w -> 1.6 + (w-400)/(800-400) * (1.55 - 1.6)
-                        w -> 1.5
+                HalfSpace.pn(Vec3.xyz( 0,  0,  8), Vec3.xyz(0.3,  1,  -1), uv -> Material.GLASS.refractiveIndex(
+                        w -> 5.6 + (w-400)/(800-400) * (1.55 - 5.6)
+
                 )),
                 HalfSpace.pn(Vec3.xyz( 0, 0,  -6), Vec3.xyz( 0,  0,  1), materialUVWallsR)
         );
 
         Collections.addAll(lights,
-                Light.ps(Vec3.xyz(0, 1.0, -1.0), w -> 1.0),
-                Light.ps(Vec3.xyz(0, -1.0, 9.0), w -> 1.0)
-
+                Light.ps(Vec3.xyz(0, 1.0, -1.0), Spectrum.WHITE),
+                Light.ps(Vec3.xyz(0, -1.0, 8.0), Spectrum.WHITE)
         );
 
         solid = Group.of(solids);