Variable particlePhysicsFragShader
particlePhysicsFragShader: "\nvarying vec2 vUV;\nvarying vec4 vColor;\nvarying vec3 vNormal;\nvarying vec3 vWorldPos;\n\nuniform vec3 lightDirection;\nuniform vec3 lightColor;\nuniform vec3 ambientColor;\n\n#ifdef TILE_BLEND\nvarying vec2 vUV2;\nvarying float vTileBlend;\n#endif\n\n#ifdef USE_MAP\nuniform sampler2D map;\n#endif\n\n// One 3×2 atlas (px py pz / nx ny nz). Avoids samplerCube and multi-face\n// sampler bindings that raise GL_INVALID_OPERATION on iOS WebKit.\n#ifdef USE_ENVMAP_ATLAS\nuniform sampler2D envAtlas;\nuniform vec3 eyePosition;\nuniform float reflectionLevel;\n\nvec3 sampleEnvAtlas(vec3 r) {\n vec3 a = abs(r);\n vec2 localUV;\n float cellX;\n float cellY;\n // Atlas layout: +X +Y +Z on row 0, -X -Y -Z on row 1.\n if (a.x >= a.y && a.x >= a.z) {\n cellX = 0.0;\n if (r.x >= 0.0) {\n cellY = 0.0;\n localUV = vec2(-r.z, -r.y) / a.x * 0.5 + 0.5;\n } else {\n cellY = 1.0;\n localUV = vec2(r.z, -r.y) / a.x * 0.5 + 0.5;\n }\n } else if (a.y >= a.z) {\n cellX = 1.0;\n if (r.y >= 0.0) {\n cellY = 0.0;\n localUV = vec2(r.x, r.z) / a.y * 0.5 + 0.5;\n } else {\n cellY = 1.0;\n localUV = vec2(r.x, -r.z) / a.y * 0.5 + 0.5;\n }\n } else {\n cellX = 2.0;\n if (r.z >= 0.0) {\n cellY = 0.0;\n localUV = vec2(r.x, -r.y) / a.z * 0.5 + 0.5;\n } else {\n cellY = 1.0;\n localUV = vec2(-r.x, -r.y) / a.z * 0.5 + 0.5;\n }\n }\n vec2 uv = (vec2(cellX, cellY) + clamp(localUV, 0.0, 1.0)) / vec2(3.0, 2.0);\n return texture2D(envAtlas, uv).rgb;\n}\n#endif\n\n#ifdef SOFT_PARTICLES\nuniform sampler2D depthTexture;\nuniform vec2 softParams;\nuniform vec4 projParams;\nvarying vec4 projPosition;\nvarying float linearDepth;\n#endif\n\n#ifdef USE_ALPHATEST\nuniform float alphaTest;\n#endif\n\nvoid main() {\n vec4 baseColor = vColor;\n\n#ifdef USE_MAP\n vec4 texColor = texture2D(map, vUV);\n #ifdef TILE_BLEND\n vec4 texColor2 = texture2D(map, vUV2);\n texColor = mix(texColor, texColor2, vTileBlend);\n #endif\n baseColor *= texColor;\n#endif\n\n#ifdef USE_ALPHATEST\n if (baseColor.a < alphaTest) discard;\n#else\n if (baseColor.a < 0.01) discard;\n#endif\n\n vec3 N = normalize(vNormal);\n vec3 L = normalize(-lightDirection);\n float NdotL = max(dot(N, L), 0.0);\n vec3 litColor = ambientColor + lightColor * NdotL;\n\n vec3 color = baseColor.rgb * litColor;\n\n#ifdef USE_ENVMAP_ATLAS\n vec3 viewDir = normalize(vWorldPos - eyePosition);\n vec3 reflectionCoords = reflect(viewDir, N);\n color += sampleEnvAtlas(reflectionCoords) * reflectionLevel;\n#endif\n\n gl_FragColor = vec4(color, baseColor.a);\n\n#ifdef SOFT_PARTICLES\n vec2 p2 = projPosition.xy / projPosition.w;\n p2 = 0.5 * p2 + 0.5;\n float readDepth = texture2D(depthTexture, p2.xy).r;\n float zNear = projParams.x;\n float zFar = projParams.y;\n float viewDepth = (zFar * zNear) / (zFar - readDepth * (zFar - zNear));\n float fade = clamp(softParams.y * ((viewDepth - softParams.x) - linearDepth), 0.0, 1.0);\n gl_FragColor *= fade;\n#endif\n}\n"