26 lines
No EOL
831 B
HLSL
26 lines
No EOL
831 B
HLSL
#ifndef FNC_SPECULAR_WARD
|
|
#define FNC_SPECULAR_WARD
|
|
|
|
// https://github.com/glslify/glsl-specular-ward
|
|
float specularWard(float3 L, float3 N, float3 V, float3 fiber, float shinyParallel, float shinyPerpendicular) {
|
|
float NdotL = dot(N, L);
|
|
float NdotR = dot(N, V);
|
|
float3 fiberParallel = normalize(fiber);
|
|
float3 fiberPerpendicular = normalize(cross(N, fiber));
|
|
|
|
if (NdotL < 0.0 || NdotR < 0.0)
|
|
return 0.0;
|
|
|
|
float3 H = normalize(L + V);
|
|
|
|
float NdotH = dot(N, H);
|
|
float XdotH = dot(fiberParallel, H);
|
|
float YdotH = dot(fiberPerpendicular, H);
|
|
|
|
float coeff = sqrt(NdotL/NdotR) / (12.5663706144 * shinyParallel * shinyPerpendicular);
|
|
float theta = (pow(XdotH/shinyParallel, 2.0) + pow(YdotH/shinyPerpendicular, 2.0)) / (1.0 + NdotH);
|
|
|
|
return coeff * exp(-2.0 * theta);
|
|
}
|
|
|
|
#endif |