oglc/shader/include/lighting.glsl

53 lines
1.4 KiB
Plaintext
Raw Normal View History

2021-08-10 02:11:22 +02:00
mat3 getTangentSpace(vec3 normal)
{
vec3 helper = abs(normal.x) > 0.99
? vec3(1.0,0.0,0.0)
: vec3(0.0,0.0,1.0);
vec3 tangent = normalize(cross(normal, helper));
vec3 binormal = normalize(cross(normal, tangent));
return mat3(tangent, binormal, normal);
}
vec3 sampleHemisphere(vec3 normal)
{
// TODO: make independent of this image uniform
ivec2 pixelCoords = ivec2(gl_GlobalInvocationID.xy);
ivec2 dims = imageSize(img_output);
vec2 uv = pixelUv(pixelCoords, dims);
2021-08-10 02:11:22 +02:00
uv += _seed.xy;
vec4 noise = sampleNoise(uv);;
float cosTheta = random(normalize(normal.xy+noise.xy));
float sinTheta = sqrt(max(0.0,1.0-cosTheta*cosTheta));
float phi = 2.0*PI*random(normalize(normal.yz+noise.xw));
vec3 tangentSpaceDir = vec3(cos(phi)*sinTheta, sin(phi)*sinTheta, cosTheta);
// convert direction from tangent space to world space
mat3 ts = getTangentSpace(normal);
return ts * tangentSpaceDir;
}
2022-01-30 23:01:02 +01:00
vec3 scatterMetal(inout Ray ray, RayHit hit)
{
ray.origin = hit.position + hit.normal*0.001;
ray.direction = reflect(ray.direction,hit.normal);
ray.energy *= 0.5;
return vec3(0.0);
}
2021-08-10 02:11:22 +02:00
vec3 scatterLambert(inout Ray ray, RayHit hit)
{
ray.origin = hit.position + hit.normal*0.001;
ray.direction = sampleHemisphere(hit.normal);
2022-01-30 23:01:02 +01:00
ray.energy *= hit.albedo * sdot(hit.normal, ray.direction);
2021-08-10 02:11:22 +02:00
return vec3(0.0);
}