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
@@ -0,0 +1,81 @@
+// MinecraftPT — Volumetric_FS
+// Volumetric fog + volumetric clouds ray marched per-pixel and composited.
+
+#include "/Lib/Settings.glsl"
+#include "/Lib/Utilities.glsl"
+#include "/Lib/BasicFunctions/LightingConstants.glsl"
+#include "/Lib/BasicFunctions/TemporalNoise.glsl"
+#include "/Lib/IndividualFunctions/VolumetricFog.glsl"
+#include "/Lib/IndividualFunctions/WaterFog.glsl"
+#include "/Lib/IndividualFunctions/PlanarClouds.glsl"
+#include "/Lib/IndividualFunctions/CloudShadow.glsl"
+
+uniform sampler2D colortex12; // HDR scene
+
+layout(location = 0) out vec4 colorOut;
+
+void main(){
+	vec2 texelCoord = gl_FragCoord.xy;
+	vec3 sceneColor = texelFetch(colortex12, ivec2(texelCoord), 0).rgb;
+
+	float depth = texelFetch(depthtex0, ivec2(texelCoord), 0).r;
+
+	// Reconstruct view position
+	vec4 viewPos = gbufferProjectionInverse * vec4(texelCoord / screenSize * 2.0 - 1.0, depth * 2.0 - 1.0, 1.0);
+	viewPos.xyz /= viewPos.w;
+
+	vec3 worldPos = gbufferModelViewInverse[3].xyz + viewPos.xyz;
+
+	// Dithering for the ray march
+	float dither = BlueNoiseTemporal();
+
+	// Volumetric fog accumulation
+	vec3 fogColor = vec3(0.0);
+	float transmittance = 1.0;
+
+	// Ray march toward the surface
+	int steps = VFOG_QUALITY;
+	float dist = length(viewPos.xyz);
+	float stepSize = dist / float(steps);
+
+	vec3 rayDir = normalize(viewPos.xyz);
+	vec3 marchPos = worldPos;
+
+	float time = frameTimeCounter * 0.05;
+
+	for (int i = 0; i < steps; i++){
+		float t = (float(i) + dither) * stepSize;
+		vec3 samplePos = marchPos - rayDir * t;
+
+		float density = GetVolumetricFogDensity(samplePos, time);
+		density *= stepSize;
+
+		// Sun scattering
+		float phase = 0.5 + 0.5 * dot(normalize(GetSunDirWorld()), -rayDir);
+
+		vec3 inscatter = GetFogColor(samplePos, GetSunDirWorld()) * density * phase;
+
+		fogColor += transmittance * inscatter;
+		transmittance *= exp(-density);
+	}
+
+	// Cloud shadow on fog
+	#ifdef VFOG_CLOUD_SHADOW
+		float cloudShadow = GetCloudShadow(worldPos);
+		fogColor *= cloudShadow;
+	#endif
+
+	// Combine
+	vec3 finalColor = sceneColor * transmittance + fogColor;
+
+	// Water fog (underwater)
+	#ifdef UNDERWATER_VFOG
+		if (isEyeInWater > 0){
+			vec3 waterColor = GetWaterFogColor(worldPos);
+			float waterFog = 1.0 - exp(-dist * GetWaterFogDensity(worldPos) * UNDERWATER_VFOG_DENSITY);
+			finalColor = mix(finalColor, waterColor * 3.0, waterFog);
+		}
+	#endif
+
+	colorOut = vec4(finalColor, 1.0);
+}