luboslenco
78 lines
2.7 KiB
GLSL
78 lines
2.7 KiB
GLSL
|
|
#ifndef _CONETRACE_GLSL_
|
|
#define _CONETRACE_GLSL_
|
|
|
|
// References
|
|
// https://github.com/Friduric/voxel-cone-tracing
|
|
// https://github.com/Cigg/Voxel-Cone-Tracing
|
|
// https://github.com/GreatBlambo/voxel_cone_tracing/
|
|
// http://simonstechblog.blogspot.com/2013/01/implementing-voxel-cone-tracing.html
|
|
// http://leifnode.com/2015/05/voxel-cone-traced-global-illumination/
|
|
// http://www.seas.upenn.edu/%7Epcozzi/OpenGLInsights/OpenGLInsights-SparseVoxelization.pdf
|
|
// https://research.nvidia.com/sites/default/files/publications/GIVoxels-pg2011-authors.pdf
|
|
|
|
uniform float coneOffset;
|
|
uniform float coneAperture;
|
|
|
|
const int voxelgiResolution = 256;
|
|
const vec3 voxelgiHalfExtents = vec3(1, 1, 1);
|
|
const float voxelgiOcc = 1.0;
|
|
const float voxelgiStep = 1.0;
|
|
const float voxelgiRange = 2.0;
|
|
const float MAX_DISTANCE = 1.73205080757 * voxelgiRange;
|
|
const float VOXEL_SIZE = (2.0 / voxelgiResolution.x) * voxelgiStep;
|
|
|
|
vec3 tangent(const vec3 n) {
|
|
vec3 t1 = cross(n, vec3(0, 0, 1));
|
|
vec3 t2 = cross(n, vec3(0, 1, 0));
|
|
if (length(t1) > length(t2)) return normalize(t1);
|
|
else return normalize(t2);
|
|
}
|
|
|
|
float traceConeAO(sampler3D voxels, const vec3 origin, vec3 dir, const float aperture, const float maxDist) {
|
|
dir = normalize(dir);
|
|
float sampleCol = 0.0;
|
|
float dist = 1.5 * VOXEL_SIZE * coneOffset;
|
|
float diam = dist * aperture;
|
|
vec3 samplePos;
|
|
while (sampleCol < 1.0 && dist < maxDist) {
|
|
samplePos = dir * dist + origin;
|
|
float mip = max(log2(diam * voxelgiResolution.x), 0);
|
|
float mipSample = textureLod(voxels, samplePos * 0.5 + vec3(0.5), mip).r;
|
|
sampleCol += (1 - sampleCol) * mipSample;
|
|
dist += max(diam / 2, VOXEL_SIZE);
|
|
diam = dist * aperture;
|
|
}
|
|
return sampleCol;
|
|
}
|
|
|
|
float traceShadow(sampler3D voxels, const vec3 origin, const vec3 dir) {
|
|
return traceConeAO(voxels, origin, dir, 0.14 * coneAperture, 2.5 * voxelgiRange);
|
|
}
|
|
|
|
float traceAO(const vec3 origin, const vec3 normal, sampler3D voxels) {
|
|
const float angleMix = 0.5f;
|
|
const float aperture = 0.55785173935;
|
|
vec3 o1 = normalize(tangent(normal));
|
|
vec3 o2 = normalize(cross(o1, normal));
|
|
vec3 c1 = 0.5f * (o1 + o2);
|
|
vec3 c2 = 0.5f * (o1 - o2);
|
|
|
|
#ifdef HLSL
|
|
const float factor = voxelgiOcc * 0.93;
|
|
#else
|
|
const float factor = voxelgiOcc * 0.90;
|
|
#endif
|
|
|
|
float col = traceConeAO(voxels, origin, normal, aperture, MAX_DISTANCE);
|
|
col += traceConeAO(voxels, origin, mix(normal, o1, angleMix), aperture, MAX_DISTANCE);
|
|
col += traceConeAO(voxels, origin, mix(normal, o2, angleMix), aperture, MAX_DISTANCE);
|
|
col += traceConeAO(voxels, origin, mix(normal, -c1, angleMix), aperture, MAX_DISTANCE);
|
|
col += traceConeAO(voxels, origin, mix(normal, -c2, angleMix), aperture, MAX_DISTANCE);
|
|
return (col / 5.0) * factor;
|
|
|
|
return 0.0;
|
|
}
|
|
|
|
#endif
|