35 lines
1.0 KiB
GLSL
35 lines
1.0 KiB
GLSL
#version 460 core
|
|
out vec4 FragColor;
|
|
in vec3 localPos;
|
|
|
|
uniform samplerCube environmentMap;
|
|
|
|
const float PI = 3.14159265359;
|
|
|
|
void main(){
|
|
vec3 normal = normalize(localPos);
|
|
|
|
vec3 irradiance = vec3(0.0);
|
|
|
|
vec3 up = vec3(0.0, 1.0, 0.0);
|
|
vec3 right = normalize(cross(up, normal));
|
|
up = normalize(cross(normal, right));
|
|
|
|
float sampleDelta = 0.025;
|
|
float nrSamples = 0.0;
|
|
|
|
for(float phi = 0.0; phi < 2.0 * PI; phi += sampleDelta){
|
|
for(float theta = 0.0; theta < 0.5 * PI; theta += sampleDelta){
|
|
// spherical to cartesian
|
|
vec3 tangentSample = vec3(sin(theta) * cos(phi), sin(theta) * sin(phi), cos(theta));
|
|
// tangent space to world
|
|
vec3 sampleVec = tangentSample.x * right + tangentSample.y * up + tangentSample.z * normal;
|
|
|
|
|
|
irradiance += texture(environmentMap, sampleVec).rgb * cos(theta) * sin(theta);
|
|
nrSamples++;
|
|
}
|
|
}
|
|
irradiance = PI * irradiance * (1.0 / float(nrSamples));
|
|
FragColor = vec4(irradiance,1.0);
|
|
} |