Initial commit: Minecraft 光追着色器包（从零实现的 path tracing）

2026-09-19 12:06:22 +08:00
commit 59e30822f8
314 changed files with 9259 additions and 0 deletions
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+#include "/Lib/Settings.glsl"
+#include "/Lib/Utilities.glsl"
+// MinecraftPT — Diffuse Spatial Filter
+// Edge-avoiding A-trous wavelet spatial filter. Multi-pass (detail levels).
+
+#ifndef DIFFUSE_SPATIAL_FILTER_GLSL
+#define DIFFUSE_SPATIAL_FILTER_GLSL
+
+#include "/Lib/Utilities.glsl"
+
+// Single A-trous pass at the given step size
+vec3 DiffuseSpatialPass(vec3 center, vec2 texelCoord, int step){
+	vec3 result = center * 0.25;
+
+	// Center depth and normal for edge detection
+	float depth = texelFetch(depthtex0, texelCoord * 2.0, 0).r;
+	vec3 normal = DecodeNormal(texelFetch(colortex1, texelCoord * 2.0, 0).xy);
+	vec3 centerAlbedo = texelFetch(colortex0, texelCoord * 2.0, 0).rgb;
+
+	// Reconstruct view position for depth edge weight
+	vec4 viewPos = gbufferProjectionInverse * vec4(texelCoord * 2.0 / screenSize * 2.0 - 1.0, depth * 2.0 - 1.0, 1.0);
+	viewPos.xyz /= viewPos.w;
+
+	float weightSum = 0.25;
+
+	vec2 offsets[4] = vec2[4](vec2(1.0, 0.0), vec2(-1.0, 0.0), vec2(0.0, 1.0), vec2(0.0, -1.0));
+
+	for (int i = 0; i < 4; i++){
+		vec2 coord = texelCoord + offsets[i] * float(step);
+		vec3 sampleColor = texelFetch(colortex7, ivec2(coord), 0).rgb;
+
+		float sampleDepth = texelFetch(depthtex0, coord * 2.0, 0).r;
+		vec3 sampleNormal = DecodeNormal(texelFetch(colortex1, coord * 2.0, 0).xy);
+
+		// Edge-avoiding weights
+		float depthWeight = exp(-abs(depth - sampleDepth) * PT_DIFFUSE_SPATIAL_FILTER_DEPTH_WEIGHT * 100.0);
+		float normalWeight = pow(max(dot(normal, sampleNormal), 0.0), 8.0 * PT_DIFFUSE_SPATIAL_FILTER_NORMAL_WEIGHT + 1.0);
+		float luminanceWeight = exp(-abs(luminance(center) - luminance(sampleColor)) * PT_DIFFUSE_SPATIAL_FILTER_LUMINANCE_WEIGHT * 10.0);
+
+		float weight = depthWeight * normalWeight * luminanceWeight;
+
+		result += sampleColor * weight;
+		weightSum += weight;
+	}
+
+	return result / weightSum;
+}
+
+// Run the spatial filter chain (detail levels)
+vec3 DiffuseSpatialFilter(vec2 texelCoord){
+	vec3 color = texelFetch(colortex7, ivec2(texelCoord), 0).rgb;
+
+	int levels = 1 + int(PT_DIFFUSE_SPATIAL_FILTER_DETAIL);
+
+	int step = 1;
+	for (int i = 0; i < levels; i++){
+		color = DiffuseSpatialPass(color, texelCoord, step);
+		step *= 2;
+	}
+
+	return color;
+}
+
+#endif
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+// MinecraftPT — Diffuse Temporal Filter
+// Reprojects the previous frame's denoised diffuse result using motion vectors
+// and accumulates with the current noisy frame.
+
+#ifndef DIFFUSE_TEMPORAL_FILTER_GLSL
+#define DIFFUSE_TEMPORAL_FILTER_GLSL
+
+#include "/Lib/Utilities.glsl"
+
+vec3 DiffuseTemporalAccumulate(vec3 current, vec2 texelCoord, vec3 prevColor){
+	vec2 motionVec = texelFetch(colortex10, ivec2(texelCoord), 0).xy;
+	vec2 prevCoord = (texelCoord + 0.5) - motionVec;
+
+	// Validate reprojection: depth comparison
+	float depth = texelFetch(depthtex0, texelCoord * 2.0, 0).r;
+	float prevDepth = textureLod(prevDepth2D, prevCoord / (screenSize * 0.5), 0.0).r;
+
+	float depthValid = step(abs(depth - prevDepth), 0.05 * depth + 0.001);
+
+	// History confidence based on accumulation count
+	float accum = 1.0 / float(PT_DIFFUSE_TEMPORAL_MAX_ACCUM);
+
+	// Sample previous
+	vec3 history = textureLod(colortex7, prevCoord / (screenSize * 0.5), 0.0).rgb;
+
+	// Neighborhood clamp to reduce ghosting
+	vec3 minColor = history;
+	vec3 maxColor = history;
+	for (int i = -1; i <= 1; i++){
+	for (int j = -1; j <= 1; j++){
+		vec3 c = textureLod(colortex7, (prevCoord + vec2(i, j)) / (screenSize * 0.5), 0.0).rgb;
+		minColor = min(minColor, c);
+		maxColor = max(maxColor, c);
+	}}
+	history = clamp(history, minColor, maxColor);
+
+	float blend = mix(accum, 1.0, depthValid * PT_DIFFUSE_TEMPORAL_HISTORY_FIX * 0.5);
+
+	return mix(current, history, blend * (1.0 - accum));
+}
+
+#endif
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+#include "/Lib/Settings.glsl"
+#include "/Lib/Utilities.glsl"
+// MinecraftPT — Diffuse Variance Estimation
+// Computes luminance moments to drive temporal accumulation and firefly rejection.
+
+#ifndef DIFFUSE_VARIANCE_ESTIMATION_GLSL
+#define DIFFUSE_VARIANCE_ESTIMATION_GLSL
+
+#include "/Lib/Utilities.glsl"
+
+vec2 DiffuseEstimateVariance(vec3 color, vec2 texelCoord){
+	float lum = luminance(color);
+	float lum2 = lum * lum;
+
+	// Local variance from neighbors (5-tap)
+	float variance = 0.0;
+	for (int i = -1; i <= 1; i++){
+	for (int j = -1; j <= 1; j++){
+		if (i == 0 && j == 0) continue;
+		vec3 c = texelFetch(colortex7, ivec2(texelCoord) + ivec2(i, j), 0).rgb;
+		float l = luminance(c);
+		variance += (l - lum) * (l - lum);
+	}}
+	variance /= 8.0;
+
+	// Clamp fireflies
+	float firefly = step(1.0, lum / max(variance * 4.0, 0.001));
+
+	return vec2(lum, firefly);
+}
+
+#endif
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+#include "/Lib/Settings.glsl"
+#include "/Lib/Utilities.glsl"
+// MinecraftPT — Specular Spatial Filter
+// Edge-avoiding spatial filter for specular reflections (fewer passes than diffuse).
+
+#ifndef SPECULAR_SPATIAL_FILTER_GLSL
+#define SPECULAR_SPATIAL_FILTER_GLSL
+
+#include "/Lib/Utilities.glsl"
+
+vec3 SpecularSpatialPass(vec3 center, vec2 texelCoord, int step){
+	vec3 result = center * 0.25;
+
+	float depth = texelFetch(depthtex0, texelCoord * 2.0, 0).r;
+	vec3 normal = DecodeNormal(texelFetch(colortex1, texelCoord * 2.0, 0).xy);
+
+	float weightSum = 0.25;
+
+	vec2 offsets[4] = vec2[4](vec2(1.0, 0.0), vec2(-1.0, 0.0), vec2(0.0, 1.0), vec2(0.0, -1.0));
+
+	for (int i = 0; i < 4; i++){
+		vec2 coord = texelCoord + offsets[i] * float(step);
+		vec3 sampleColor = texelFetch(colortex11, ivec2(coord), 0).rgb;
+
+		float sampleDepth = texelFetch(depthtex0, coord * 2.0, 0).r;
+		vec3 sampleNormal = DecodeNormal(texelFetch(colortex1, coord * 2.0, 0).xy);
+
+		float depthWeight = exp(-abs(depth - sampleDepth) * PT_DIFFUSE_SPATIAL_FILTER_DEPTH_WEIGHT * 100.0);
+		float normalWeight = pow(max(dot(normal, sampleNormal), 0.0), 8.0 * PT_DIFFUSE_SPATIAL_FILTER_NORMAL_WEIGHT + 1.0);
+		float luminanceWeight = exp(-abs(luminance(center) - luminance(sampleColor)) * PT_DIFFUSE_SPATIAL_FILTER_LUMINANCE_WEIGHT * 10.0);
+
+		float weight = depthWeight * normalWeight * luminanceWeight;
+
+		result += sampleColor * weight;
+		weightSum += weight;
+	}
+
+	return result / weightSum;
+}
+
+vec3 SpecularSpatialFilter(vec2 texelCoord){
+	vec3 color = texelFetch(colortex11, ivec2(texelCoord), 0).rgb;
+
+	int levels = 1 + int(PT_DIFFUSE_SPATIAL_FILTER_DETAIL) / 2;
+
+	int step = 1;
+	for (int i = 0; i < levels; i++){
+		color = SpecularSpatialPass(color, texelCoord, step);
+		step *= 2;
+	}
+
+	return color;
+}
+
+#endif
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+// MinecraftPT — Specular Temporal Filter
+// Temporal accumulation for specular reflections with reprojection.
+
+#ifndef SPECULAR_TEMPORAL_FILTER_GLSL
+#define SPECULAR_TEMPORAL_FILTER_GLSL
+
+#include "/Lib/Utilities.glsl"
+
+vec3 SpecularTemporalAccumulate(vec3 current, vec2 texelCoord){
+	vec2 motionVec = texelFetch(colortex10, ivec2(texelCoord), 0).xy;
+	vec2 prevCoord = (texelCoord + 0.5) - motionVec;
+
+	float depth = texelFetch(depthtex0, texelCoord * 2.0, 0).r;
+	float prevDepth = textureLod(prevDepth2D, prevCoord / (screenSize * 0.5), 0.0).r;
+
+	float depthValid = step(abs(depth - prevDepth), 0.05 * depth + 0.001);
+
+	float accum = 1.0 / float(PT_DIFFUSE_TEMPORAL_MAX_ACCUM);
+
+	vec3 history = textureLod(colortex11, prevCoord / (screenSize * 0.5), 0.0).rgb;
+
+	// Neighborhood clamp
+	vec3 minColor = history;
+	vec3 maxColor = history;
+	for (int i = -1; i <= 1; i++){
+	for (int j = -1; j <= 1; j++){
+		vec3 c = textureLod(colortex11, (prevCoord + vec2(i, j)) / (screenSize * 0.5), 0.0).rgb;
+		minColor = min(minColor, c);
+		maxColor = max(maxColor, c);
+	}}
+	history = clamp(history, minColor, maxColor);
+
+	float blend = mix(accum, 1.0, depthValid * PT_DIFFUSE_TEMPORAL_HISTORY_FIX * 0.5);
+
+	return mix(current, history, blend * (1.0 - accum));
+}
+
+#endif