59 lines
1.3 KiB
GLSL
59 lines
1.3 KiB
GLSL
struct Vertex
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{
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vec3 pos;
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vec3 nrm;
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vec3 color;
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vec2 texCoord;
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};
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struct WaveFrontMaterial
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{
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vec3 ambient;
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vec3 diffuse;
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vec3 specular;
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vec3 transmittance;
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vec3 emission;
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float shininess;
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float ior; // index of refraction
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float dissolve; // 1 == opaque; 0 == fully transparent
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int illum; // illumination model (see http://www.fileformat.info/format/material/)
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int textureId;
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};
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struct sceneDesc
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{
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int objId;
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int txtOffset;
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mat4 transfo;
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mat4 transfoIT;
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int hitGroup;
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};
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vec3 computeDiffuse(WaveFrontMaterial mat, vec3 lightDir, vec3 normal)
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{
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// Lambertian
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float dotNL = max(dot(normal, lightDir), 0.0);
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vec3 c = mat.diffuse * dotNL;
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if(mat.illum >= 1)
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c += mat.ambient;
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return c;
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}
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vec3 computeSpecular(WaveFrontMaterial mat, vec3 viewDir, vec3 lightDir, vec3 normal)
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{
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if(mat.illum < 2)
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return vec3(0);
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// Compute specular only if not in shadow
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const float kPi = 3.14159265;
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const float kShininess = max(mat.shininess, 4.0);
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// Specular
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const float kEnergyConservation = (2.0 + kShininess) / (2.0 * kPi);
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vec3 V = normalize(-viewDir);
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vec3 R = reflect(-lightDir, normal);
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float specular = kEnergyConservation * pow(max(dot(V, R), 0.0), kShininess);
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return vec3(mat.specular * specular);
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}
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