clara/bluenoise-raytracer
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

ray_tracing_gltf: Match samplingHemisphere to Ray Tracing Gems implementation and avoid generating directions perpendicular to +z; adjust comments on Lambertian PDF and match docs.

Browse source
This commit is contained in:
NeilBickford-NV 2023-05-23 14:45:28 -07:00
parent c436c46141
commit 80e00cae4e
3 changed files with 20 additions and 14 deletions
Download patch file Download diff file Expand all files Collapse all files

18
ray_tracing_gltf/README.md
View file

@ -452,8 +452,8 @@ struct hitPayload
This modification will recursively trace until the `depth`hits 10 (hardcoded) or hit an emissive element (light).
The only information that we will keep from the shader, is the calculation of the hit state: position, normal. So
all code from `// Vector toward the light` to the end can be remove and be replaced by the following.
The only information that we will keep from the shader, is the calculation of the hit state: the position and normal. So
all code from `// Vector toward the light` to the end can be removed and be replaced by the following.
~~~~C
// https://en.wikipedia.org/wiki/Path_tracing
@ -467,12 +467,18 @@ all code from `// Vector toward the light` to the end can be remove and be repla
vec3 rayOrigin = world_position;
vec3 rayDirection = samplingHemisphere(prd.seed, tangent, bitangent, world_normal);
// Probability of the newRay (cosine distributed)
const float p = 1 / M_PI;
const float cos_theta = dot(rayDirection, world_normal);
// Probability density function of samplingHemisphere choosing this rayDirection
const float p = cos_theta / M_PI;
// Compute the BRDF for this ray (assuming Lambertian reflection)
float cos_theta = dot(rayDirection, world_normal);
vec3 BRDF = mat.pbrBaseColorFactor.xyz / M_PI;
vec3 albedo = mat.pbrBaseColorFactor.xyz;
if(mat.pbrBaseColorTexture > -1)
{
uint txtId = mat.pbrBaseColorTexture;
albedo *= texture(texturesMap[nonuniformEXT(txtId)], texcoord0).xyz;
}
vec3 BRDF = albedo / M_PI;
// Recursively trace reflected light sources.
if(prd.depth < 10)