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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+// MinecraftPT — SkyImage_CS
+// Precomputes the sky panorama (skyBox2D, 3:2 cubemap cross) using the analytic
+// atmosphere model, for sampling by the path tracer and reflections.
+
+#include "/Lib/Settings.glsl"
+#include "/Lib/Utilities.glsl"
+#include "/Lib/BasicFunctions/LightingConstants.glsl"
+#include "/Lib/BasicFunctions/PrecomputedAtmosphere.glsl"
+#include "/Lib/IndividualFunctions/EndSky.glsl"
+#include "/Lib/IndividualFunctions/PlanarClouds.glsl"
+
+const ivec3 workGroups = ivec3(int(ceil(float(SKYBOX_RESOLUTION_X) / 8.0)), int(ceil(float(SKYBOX_RESOLUTION_Y) / 8.0)), 1);
+layout (local_size_x = 8, local_size_y = 8) in;
+
+layout (rgba16f) uniform writeonly image2D img_skyBox2D;
+
+void main(){
+	ivec2 texel = ivec2(gl_GlobalInvocationID.xy);
+
+	// Panorama layout: 3:2 cross (like a cubemap cross folded)
+	vec2 resolution = vec2(SKYBOX_RESOLUTION_X, SKYBOX_RESOLUTION_Y);
+	vec2 uv = (vec2(texel) + 0.5) / resolution;
+
+	// Determine face and local UV
+	float tileX = SKYBOX_RESOLUTION / resolution.x; // 1/3
+	float tileY = SKYBOX_RESOLUTION / resolution.y; // 1/2
+
+	int face = int(floor(uv.x / tileX));
+	vec2 faceUV = vec2(
+		(uv.x - float(face) * tileX) / tileX,
+		(uv.y - float(face < 3 ? 0 : 1) * tileY) / tileY
+	);
+	faceUV = faceUV * 2.0 - 1.0;
+
+	// Cubemap cross mapping (Standard OpenGL cross layout, 4x3 grid):
+	// faces: 0=+X, 1=-X, 2=+Y, 3=-Y, 4=+Z, 5=-Z (top row: +X -X +Y; bottom row: -Y +Z -Z)
+	// This panorama is a 3x2 layout, so: top row = +X, -X, +Y; bottom row = -Y, +Z, -Z
+	vec3 dir;
+	if (face == 0){       // +X
+		dir = vec3(1.0, -faceUV.y, -faceUV.x);
+	}else if (face == 1){ // -X
+		dir = vec3(-1.0, -faceUV.y, faceUV.x);
+	}else if (face == 2){ // +Y
+		dir = vec3(faceUV.x, 1.0, -faceUV.y);
+	}else if (face == 3){ // -Y
+		dir = vec3(faceUV.x, -1.0, faceUV.y);
+	}else if (face == 4){ // +Z
+		dir = vec3(faceUV.x, -faceUV.y, 1.0);
+	}else{                // -Z
+		dir = vec3(-faceUV.x, -faceUV.y, -1.0);
+	}
+
+	dir = normalize(dir);
+
+	vec3 sunDir = GetSunDirWorld();
+
+	// Sky radiance from analytic atmosphere
+	vec3 color = GetSkyRadiance(dir, sunDir);
+
+	// Stars at night
+	float night = 1.0 - curve(saturate(sunDir.y * 10.0 + 0.5));
+	if (night > 0.5){
+		float stars = 0.0;
+		vec3 starSeed = floor(dir * 64.0);
+		float star = hash1(starSeed);
+		stars = step(0.998, star) * 2.0;
+		color += vec3(1.0, 1.0, 1.0) * stars * night;
+	}
+
+	// End dimension sky
+	#ifdef DIMENSION_END
+		color = GetEndSky(dir, sunDir);
+	#endif
+
+	imageStore(img_skyBox2D, texel, vec4(color, 0.0));
+}