25 lines
837 B
GLSL
25 lines
837 B
GLSL
mat3 GetLightmapTBN(vec3 viewPos) {
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mat3 lightmapTBN = mat3(normalize(dFdx(viewPos)), normalize(dFdy(viewPos)), vec3(0.0));
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lightmapTBN[2] = cross(lightmapTBN[0], lightmapTBN[1]);
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return lightmapTBN;
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}
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float DirectionalLightmap(float lightmap, float lightmapRaw, vec3 normal, mat3 lightmapTBN) {
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if (lightmap < 0.001) return lightmap;
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vec2 deriv = vec2(dFdx(lightmapRaw), dFdy(lightmapRaw)) * 256.0;
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vec3 dir = normalize(vec3(
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deriv.x * lightmapTBN[0] +
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0.0005 * lightmapTBN[2] +
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deriv.y * lightmapTBN[1]
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));
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float pwr = clamp(dot(normal, dir), -1.0, 1.0);
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if (abs(pwr) > 0.0)
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pwr = pow(abs(pwr), DIRECTIONAL_LIGHTMAP_STRENGTH) * sign(pwr) * lightmap;
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if (length(deriv) > 0.001)
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lightmap = pow(lightmap, max(1.0 - pwr, 0.001));
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return lightmap;
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} |