Clément Foucault
dccf46f18f
Early implementation. Slow and still has quality 3 ways of storing irradiance: - Spherical Harmonics: Have problem with directionnal lighting. - HL2 diffuse cube: Very low resolution but smooth transitions. - Diffuse cube: High storage requirement. Also include some name change.
73 lines
1.5 KiB
GLSL
73 lines
1.5 KiB
GLSL
|
|
uniform sampler1D texHammersley;
|
|
uniform sampler2D texJitter;
|
|
uniform float sampleCount;
|
|
uniform float invSampleCount;
|
|
|
|
vec2 jitternoise = vec2(0.0);
|
|
|
|
void setup_noise(void)
|
|
{
|
|
jitternoise = texture(texJitter, gl_FragCoord.xy / NOISE_SIZE).rg; /* Global variable */
|
|
}
|
|
|
|
vec3 hammersley_3d(float i, float invsamplenbr)
|
|
{
|
|
vec3 Xi; /* Theta, cos(Phi), sin(Phi) */
|
|
|
|
Xi.x = i * invsamplenbr; /* i/samples */
|
|
Xi.x = fract(Xi.x + jitternoise.x);
|
|
|
|
int u = int(mod(i + jitternoise.y * HAMMERSLEY_SIZE, HAMMERSLEY_SIZE));
|
|
|
|
Xi.yz = texelFetch(texHammersley, u, 0).rg;
|
|
|
|
return Xi;
|
|
}
|
|
|
|
vec3 hammersley_3d(float i)
|
|
{
|
|
return hammersley_3d(i, invSampleCount);
|
|
}
|
|
|
|
/* -------------- BSDFS -------------- */
|
|
|
|
float pdf_ggx_reflect(float NH, float a2)
|
|
{
|
|
return NH * a2 / D_ggx_opti(NH, a2);
|
|
}
|
|
|
|
float pdf_hemisphere()
|
|
{
|
|
return 0.5 * M_1_PI;
|
|
}
|
|
|
|
vec3 sample_ggx(float nsample, float a2, vec3 N, vec3 T, vec3 B)
|
|
{
|
|
vec3 Xi = hammersley_3d(nsample);
|
|
|
|
/* Theta is the aperture angle of the cone */
|
|
float z = sqrt( (1.0 - Xi.x) / ( 1.0 + a2 * Xi.x - Xi.x ) ); /* cos theta */
|
|
float r = sqrt( 1.0 - z * z ); /* sin theta */
|
|
float x = r * Xi.y;
|
|
float y = r * Xi.z;
|
|
|
|
/* Microfacet Normal */
|
|
vec3 Ht = vec3(x, y, z);
|
|
|
|
return tangent_to_world(Ht, N, T, B);
|
|
}
|
|
|
|
vec3 sample_hemisphere(float nsample, vec3 N, vec3 T, vec3 B)
|
|
{
|
|
vec3 Xi = hammersley_3d(nsample);
|
|
|
|
float z = Xi.x; /* cos theta */
|
|
float r = sqrt( 1.0f - z*z ); /* sin theta */
|
|
float x = r * Xi.y;
|
|
float y = r * Xi.z;
|
|
|
|
vec3 Ht = vec3(x, y, z);
|
|
|
|
return tangent_to_world(Ht, N, T, B);
|
|
} |