46 lines
975 B
GLSL
46 lines
975 B
GLSL
#ifndef EV_GLSL_PBR_H
|
|
#define EV_GLSL_PBR_H
|
|
|
|
float DistributionGGX(vec3 N, vec3 H, float a)
|
|
{
|
|
float a2 = a*a;
|
|
float NdotH = max(dot(N,H),0.0);
|
|
float NdotH2 = NdotH*NdotH;
|
|
|
|
float num = a2;
|
|
float denom = (NdotH2 * (a2 - 1.0) + 1.0);
|
|
denom = PI * denom * denom;
|
|
|
|
return num/denom;
|
|
}
|
|
|
|
float GeometrySchlickGGX(float NdotV, float k)
|
|
{
|
|
float nom = NdotV;
|
|
float denom = NdotV * (1.0 - k) + k;
|
|
|
|
return nom / denom;
|
|
}
|
|
|
|
float GeometrySmith(vec3 N, vec3 V, vec3 L, float k)
|
|
{
|
|
float NdotV = max(dot(N, V), 0.0);
|
|
float NdotL = max(dot(N, L), 0.0);
|
|
float ggx1 = GeometrySchlickGGX(NdotV, k);
|
|
float ggx2 = GeometrySchlickGGX(NdotL, k);
|
|
|
|
return ggx1 * ggx2;
|
|
}
|
|
|
|
vec3 fresnelSchlick(float cosTheta, vec3 F0)
|
|
{
|
|
return F0 + (1.0 - F0) * pow(1.0 - cosTheta, 5.0);
|
|
}
|
|
|
|
vec3 fresnelSchlickRoughness(float cosTheta, vec3 F0, float roughness)
|
|
{
|
|
return F0 + (max(vec3(1.0 - roughness), F0) - F0) * pow(max(1.0 - cosTheta, 0.0), 5.0);
|
|
}
|
|
|
|
#endif
|