| 67312b79 |
1 | // This file has been automatically generated from resource file src/Shaders/PBREnvBaking.fs |
| 2 | |
| 3 | static const char Shaders_PBREnvBaking_fs[] = |
| 4 | "THE_SHADER_IN vec3 ViewDirection; //!< direction of fetching from environment cubemap\n" |
| 5 | "\n" |
| 6 | "uniform int uSamplesNum; //!< number of samples in Monte-Carlo integration\n" |
| 7 | "uniform int uCurrentLevel; //!< current level of specular IBL map (ignored in case of diffuse map's processing)\n" |
| 8 | "uniform int uEnvMapSize; //!< one edge's size of source environtment map's zero mipmap level\n" |
| 9 | "uniform int uYCoeff; //!< coefficient of Y controlling horizontal flip of cubemap\n" |
| 10 | "uniform int uZCoeff; //!< coefficient of Z controlling vertical flip of cubemap\n" |
| 11 | "uniform samplerCube uEnvMap; //!< source of baking (environment cubemap)\n" |
| 12 | "\n" |
| 13 | "//! Returns coordinates of point theNumber from Hammersley point set having size theSize.\n" |
| 14 | "vec2 hammersley (in int theNumber,\n" |
| 15 | " in int theSize)\n" |
| 16 | "{\n" |
| 17 | " int aDenominator = 2;\n" |
| 18 | " int aNumber = theNumber;\n" |
| 19 | " float aVanDerCorput = 0.0;\n" |
| 20 | " for (int i = 0; i < 32; ++i)\n" |
| 21 | " {\n" |
| 22 | " if (aNumber > 0)\n" |
| 23 | " {\n" |
| 24 | " aVanDerCorput += float(aNumber % 2) / float(aDenominator);\n" |
| 25 | " aNumber /= 2;\n" |
| 26 | " aDenominator *= 2;\n" |
| 27 | " }\n" |
| 28 | " }\n" |
| 29 | " return vec2(float(theNumber) / float(theSize), aVanDerCorput);\n" |
| 30 | "}\n" |
| 31 | "\n" |
| 32 | "//! This function does importance sampling on hemisphere surface using GGX normal distribution function\n" |
| 33 | "//! in tangent space (positive z axis is surface normal direction).\n" |
| 34 | "vec3 importanceSample (in vec2 theHammersleyPoint,\n" |
| 35 | " in float theRoughness)\n" |
| 36 | "{\n" |
| 37 | " float aPhi = PI_2 * theHammersleyPoint.x;\n" |
| 38 | " theRoughness *= theRoughness;\n" |
| 39 | " theRoughness *= theRoughness;\n" |
| 40 | " float aCosTheta = sqrt((1.0 - theHammersleyPoint.y) / (1.0 + (theRoughness - 1.0) * theHammersleyPoint.y));\n" |
| 41 | " float aSinTheta = sqrt(1.0 - aCosTheta * aCosTheta);\n" |
| 42 | " return vec3(aSinTheta * cos(aPhi),\n" |
| 43 | " aSinTheta * sin(aPhi),\n" |
| 44 | " aCosTheta);\n" |
| 45 | "}\n" |
| 46 | "\n" |
| 47 | "//! This function uniformly generates samples on whole sphere.\n" |
| 48 | "vec3 sphereUniformSample (in vec2 theHammersleyPoint)\n" |
| 49 | "{\n" |
| 50 | " float aPhi = PI_2 * theHammersleyPoint.x;\n" |
| 51 | " float aCosTheta = 2.0 * theHammersleyPoint.y - 1.0;\n" |
| 52 | " float aSinTheta = sqrt(1.0 - aCosTheta * aCosTheta);\n" |
| 53 | " return vec3(aSinTheta * cos(aPhi),\n" |
| 54 | " aSinTheta * sin(aPhi),\n" |
| 55 | " aCosTheta);\n" |
| 56 | "}\n" |
| 57 | "\n" |
| 58 | "//! Transforms resulted sampled direction from tangent space to world space considering the surface normal.\n" |
| 59 | "vec3 fromTangentSpace (in vec3 theVector,\n" |
| 60 | " in vec3 theNormal)\n" |
| 61 | "{\n" |
| 62 | " vec3 anUp = (abs(theNormal.z) < 0.999) ? vec3(0.0, 0.0, 1.0) : vec3(1.0, 0.0, 0.0);\n" |
| 63 | " vec3 anX = normalize(cross(anUp, theNormal));\n" |
| 64 | " vec3 anY = cross(theNormal, anX);\n" |
| 65 | " return anX * theVector.x + anY * theVector.y + theNormal * theVector.z;\n" |
| 66 | "}\n" |
| 67 | "\n" |
| 68 | "const float aSHBasisFuncCoeffs[9] = float[9]\n" |
| 69 | "(\n" |
| 70 | " 0.282095 * 0.282095,\n" |
| 71 | " 0.488603 * 0.488603,\n" |
| 72 | " 0.488603 * 0.488603,\n" |
| 73 | " 0.488603 * 0.488603,\n" |
| 74 | " 1.092548 * 1.092548,\n" |
| 75 | " 1.092548 * 1.092548,\n" |
| 76 | " 1.092548 * 1.092548,\n" |
| 77 | " 0.315392 * 0.315392,\n" |
| 78 | " 0.546274 * 0.546274\n" |
| 79 | ");\n" |
| 80 | "\n" |
| 81 | "const float aSHCosCoeffs[9] = float[9]\n" |
| 82 | "(\n" |
| 83 | " 3.141593,\n" |
| 84 | " 2.094395,\n" |
| 85 | " 2.094395,\n" |
| 86 | " 2.094395,\n" |
| 87 | " 0.785398,\n" |
| 88 | " 0.785398,\n" |
| 89 | " 0.785398,\n" |
| 90 | " 0.785398,\n" |
| 91 | " 0.785398\n" |
| 92 | ");\n" |
| 93 | "\n" |
| 94 | "//! Bakes diffuse IBL map's spherical harmonics coefficients.\n" |
| 95 | "vec3 bakeDiffuseSH()\n" |
| 96 | "{\n" |
| 97 | " int anIndex = int(gl_FragCoord.x);\n" |
| 98 | " vec3 aResult = vec3 (0.0);\n" |
| 99 | " for (int aSampleIter = 0; aSampleIter < uSamplesNum; ++aSampleIter)\n" |
| 100 | " {\n" |
| 101 | " vec2 aHammersleyPoint = hammersley (aSampleIter, uSamplesNum);\n" |
| 102 | " vec3 aDirection = sphereUniformSample (aHammersleyPoint);\n" |
| 103 | "\n" |
| 104 | " vec3 aValue = occTextureCube (uEnvMap, cubemapVectorTransform (aDirection, uYCoeff, uZCoeff)).rgb;\n" |
| 105 | "\n" |
| 106 | " float aBasisFunc[9];\n" |
| 107 | " aBasisFunc[0] = 1.0;\n" |
| 108 | "\n" |
| 109 | " aBasisFunc[1] = aDirection.x;\n" |
| 110 | " aBasisFunc[2] = aDirection.y;\n" |
| 111 | " aBasisFunc[3] = aDirection.z;\n" |
| 112 | "\n" |
| 113 | " aBasisFunc[4] = aDirection.x * aDirection.z;\n" |
| 114 | " aBasisFunc[5] = aDirection.y * aDirection.z;\n" |
| 115 | " aBasisFunc[6] = aDirection.x * aDirection.y;\n" |
| 116 | "\n" |
| 117 | " aBasisFunc[7] = 3.0 * aDirection.z * aDirection.z - 1.0;\n" |
| 118 | " aBasisFunc[8] = aDirection.x * aDirection.x - aDirection.y * aDirection.y;\n" |
| 119 | "\n" |
| 120 | " aResult += aValue * aBasisFunc[anIndex];\n" |
| 121 | " }\n" |
| 122 | "\n" |
| 123 | " aResult *= 4.0 * aSHCosCoeffs[anIndex] * aSHBasisFuncCoeffs[anIndex] / float(uSamplesNum);\n" |
| 124 | " return aResult;\n" |
| 125 | "}\n" |
| 126 | "\n" |
| 127 | "//! Bakes specular IBL map.\n" |
| 128 | "vec3 bakeSpecularMap (in vec3 theNormal,\n" |
| 129 | " in float theRoughness)\n" |
| 130 | "{\n" |
| 131 | " vec3 aResult = vec3(0.0);\n" |
| 132 | " float aWeightSum = 0.0;\n" |
| 133 | " int aSamplesNum = (theRoughness == 0.0) ? 1 : uSamplesNum;\n" |
| 134 | " float aSolidAngleSource = 4.0 * PI / (6.0 * float(uEnvMapSize * uEnvMapSize));\n" |
| 135 | " for (int aSampleIter = 0; aSampleIter < aSamplesNum; ++aSampleIter)\n" |
| 136 | " {\n" |
| 137 | " vec2 aHammersleyPoint = hammersley (aSampleIter, aSamplesNum);\n" |
| 138 | " vec3 aHalf = importanceSample (aHammersleyPoint, occRoughness (theRoughness));\n" |
| 139 | " float aHdotV = aHalf.z;\n" |
| 140 | " aHalf = fromTangentSpace (aHalf, theNormal);\n" |
| 141 | " vec3 aLight = -reflect (theNormal, aHalf);\n" |
| 142 | " float aNdotL = dot (aLight, theNormal);\n" |
| 143 | " if (aNdotL > 0.0)\n" |
| 144 | " {\n" |
| 145 | " float aSolidAngleSample = 1.0 / (float(aSamplesNum) * (occPBRDistribution (aHdotV, theRoughness) * 0.25 + 0.0001) + 0.0001);\n" |
| 146 | " float aLod = (theRoughness == 0.0) ? 0.0 : 0.5 * log2 (aSolidAngleSample / aSolidAngleSource);\n" |
| 147 | " aResult += occTextureCubeLod (uEnvMap, aLight, aLod).rgb * aNdotL;\n" |
| 148 | " aWeightSum += aNdotL;\n" |
| 149 | " }\n" |
| 150 | " }\n" |
| 151 | " return aResult / aWeightSum;\n" |
| 152 | "}\n" |
| 153 | "\n" |
| 154 | "void main()\n" |
| 155 | "{\n" |
| 156 | " vec3 aViewDirection = normalize (ViewDirection);\n" |
| 157 | " if (occNbSpecIBLLevels == 0)\n" |
| 158 | " {\n" |
| 159 | " occSetFragColor (vec4 (bakeDiffuseSH (), 1.0));\n" |
| 160 | " }\n" |
| 161 | " else\n" |
| 162 | " {\n" |
| 163 | " occSetFragColor (vec4 (bakeSpecularMap (aViewDirection, float(uCurrentLevel) / float(occNbSpecIBLLevels - 1)), 1.0));\n" |
| 164 | " }\n" |
| 165 | "}\n"; |
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