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57 行
2.9 KiB
57 行
2.9 KiB
real3 ADD_FUNC_SUFFIX(ADD_NORMAL_FUNC_SUFFIX(SampleUVMappingNormal))(TEXTURE2D_PARAM(textureName, samplerName), UVMapping uvMapping, real scale, real param)
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{
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if (uvMapping.mappingType == UV_MAPPING_TRIPLANAR)
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{
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real3 triplanarWeights = uvMapping.triplanarWeights;
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#ifdef SURFACE_GRADIENT
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// Height map gradient. Basically, it encodes height map slopes along S and T axes.
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real2 derivXplane;
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real2 derivYPlane;
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real2 derivZPlane;
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derivXplane = derivYPlane = derivZPlane = real2(0.0, 0.0);
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if (triplanarWeights.x > 0.0)
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derivXplane = triplanarWeights.x * UNPACK_DERIVATIVE_FUNC(SAMPLE_TEXTURE_FUNC(textureName, samplerName, uvMapping.uvZY, param), scale);
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if (triplanarWeights.y > 0.0)
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derivYPlane = triplanarWeights.y * UNPACK_DERIVATIVE_FUNC(SAMPLE_TEXTURE_FUNC(textureName, samplerName, uvMapping.uvXZ, param), scale);
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if (triplanarWeights.z > 0.0)
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derivZPlane = triplanarWeights.z * UNPACK_DERIVATIVE_FUNC(SAMPLE_TEXTURE_FUNC(textureName, samplerName, uvMapping.uvXY, param), scale);
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// Assume derivXplane, derivYPlane and derivZPlane sampled using (z,y), (z,x) and (x,y) respectively.
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// TODO: Check with morten convention! Do it follow ours ?
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real3 volumeGrad = real3(derivZPlane.x + derivYPlane.x, derivZPlane.y + derivXplane.y, derivXplane.x + derivYPlane.y);
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return SurfaceGradientFromVolumeGradient(uvMapping.normalWS, volumeGrad);
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#else
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real3 val = real3(0.0, 0.0, 0.0);
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if (triplanarWeights.x > 0.0)
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val += triplanarWeights.x * UNPACK_NORMAL_FUNC(SAMPLE_TEXTURE_FUNC(textureName, samplerName, uvMapping.uvZY, param), scale);
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if (triplanarWeights.y > 0.0)
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val += triplanarWeights.y * UNPACK_NORMAL_FUNC(SAMPLE_TEXTURE_FUNC(textureName, samplerName, uvMapping.uvXZ, param), scale);
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if (triplanarWeights.z > 0.0)
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val += triplanarWeights.z * UNPACK_NORMAL_FUNC(SAMPLE_TEXTURE_FUNC(textureName, samplerName, uvMapping.uvXY, param), scale);
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return normalize(val);
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#endif
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}
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#ifdef SURFACE_GRADIENT
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else if (uvMapping.mappingType == UV_MAPPING_PLANAR)
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{
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// Note: Planar is on uv coordinate (and not uvXZ)
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real2 derivYPlane = UNPACK_DERIVATIVE_FUNC(SAMPLE_TEXTURE_FUNC(textureName, samplerName, uvMapping.uv, param), scale);
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// See comment above
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real3 volumeGrad = real3(derivYPlane.x, 0.0, derivYPlane.y);
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return SurfaceGradientFromVolumeGradient(uvMapping.normalWS, volumeGrad);
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}
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#endif
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else
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{
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#ifdef SURFACE_GRADIENT
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real2 deriv = UNPACK_DERIVATIVE_FUNC(SAMPLE_TEXTURE_FUNC(textureName, samplerName, uvMapping.uv, param), scale);
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return SurfaceGradientFromTBN(deriv, uvMapping.tangentWS, uvMapping.bitangentWS);
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#else
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return UNPACK_NORMAL_FUNC(SAMPLE_TEXTURE_FUNC(textureName, samplerName, uvMapping.uv, param), scale);
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#endif
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}
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}
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