playcanvas/build/playcanvas/src/scene/shader-lib/glsl/chunks/gsplat/vert/formats/sog.d.ts

Open-source WebGL/WebGPU 3D engine for the web

declare const _default: "\n// means dequantization (both V1 and V2)\nuniform vec3 means_mins;\nuniform vec3 means_maxs;\n\n#ifndef SOG_V2\n    // V1: linear min/max dequantization (no codebooks)\n    uniform vec3 scales_mins;\n    uniform vec3 scales_maxs;\n    uniform vec4 sh0_mins;\n    uniform vec4 sh0_maxs;\n#endif\n\n// SH_C0 coefficient for 0th degree spherical harmonic\nconst float SH_C0 = 0.28209479177387814;\nconst float norm = sqrt(2.0);\n\n#ifdef SOG_V2\n    // 256x1 RGBA32F LUT:\n    //   .r = scales codebook, .g = sh0 codebook, .b = shN codebook, .a unused\n    float lutScales(int b) { return texelFetch(sogCodebook, ivec2(b, 0), 0).r; }\n    float lutSh0(int b)    { return texelFetch(sogCodebook, ivec2(b, 0), 0).g; }\n    float lutShN(int b)    { return texelFetch(sogCodebook, ivec2(b, 0), 0).b; }\n#endif\n\n// read the model-space center of the gaussian (16-bit per-axis, low + high byte)\nvec3 getCenter() {\n    vec3 l = texelFetch(means_l, splat.uv, 0).xyz;\n    vec3 u = texelFetch(means_u, splat.uv, 0).xyz;\n    vec3 n = (l + u * 256.0) / 257.0;\n    vec3 v = mix(means_mins, means_maxs, n);\n    return sign(v) * (exp(abs(v)) - 1.0);\n}\n\n// decode rotation quaternion (3 components + 2-bit mode selecting the omitted axis)\nvec4 getRotation() {\n    vec4 q = texelFetch(quats, splat.uv, 0);\n    uint qmode = uint(q.w * 255.0 + 0.5) - 252u;\n    vec3 abc = (q.xyz - 0.5) * norm;\n    float d = sqrt(max(0.0, 1.0 - dot(abc, abc)));\n    return (qmode == 0u) ? vec4(d, abc) :\n           ((qmode == 1u) ? vec4(abc.x, d, abc.yz) :\n           ((qmode == 2u) ? vec4(abc.xy, d, abc.z) : vec4(abc, d)));\n}\n\nvec3 getScale() {\n    vec3 s = texelFetch(scales, splat.uv, 0).xyz;\n    #ifdef SOG_V2\n        ivec3 i = ivec3(s * 255.0 + 0.5);\n        vec3 logS = vec3(lutScales(i.x), lutScales(i.y), lutScales(i.z));\n    #else\n        vec3 logS = mix(scales_mins, scales_maxs, s);\n    #endif\n    return exp(logS);\n}\n\nvec4 getColor() {\n    vec4 c = texelFetch(sh0, splat.uv, 0);\n    #ifdef SOG_V2\n        ivec3 i = ivec3(c.xyz * 255.0 + 0.5);\n        vec3 rgb = vec3(lutSh0(i.x), lutSh0(i.y), lutSh0(i.z));\n        float alpha = c.w;\n    #else\n        vec3 rgb = mix(sh0_mins.xyz, sh0_maxs.xyz, c.xyz);\n        float logitAlpha = mix(sh0_mins.w, sh0_maxs.w, c.w);\n        float alpha = 1.0 / (1.0 + exp(-logitAlpha));\n    #endif\n    return vec4(vec3(0.5) + rgb * SH_C0, alpha);\n}\n\n#include \"gsplatSogSHVS\"\n";
export default _default;