Questions tagged [importance-sampling]
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69 questions
2 votes
0 answers
57 views
Is MIS needed to sample different types of lights with RIS?
I'm looking into sampling different types of lights using RIS, namely spheres and env maps. But I'm wondering if, since all the proposal samples in "regular" RIS come from one proposal ...
- 21
1 vote
0 answers
117 views
How to importance sample emissive textures on meshes?
I have a mesh in my scene. That mesh has an emissive texture mapped on it. For my direct lighting integration, I'll need to sample that mesh. I could sample it uniformly and read the emissive texture ...
- 301
1 vote
1 answer
98 views
Distance sampling with unbiased transmittance estimators
I'm currently trying some things with transmittance estimators in PBRT and I have implemented the following paper: Unbiased Ray-Marching Transmittance Estimator. This method assumes that two points $x$...
- 36
2 votes
0 answers
352 views
"Charlie" Sheen BRDF's directional albedo integrates to values higher than 1 at low roughnesses. Does this mean it is not energy conserving?
I am implementing the BRDF from the 2017 paper "Production Friendly Microfacet Sheen BRDF". This BRDF is modelled as a coat layer stacked on top of a base specular. In order to do so in an ...
- 53
0 votes
1 answer
258 views
How does a path tracer capture light falloff if it deals exclusively with radiance?
My understanding is that path tracers deal with radiance because radiance is constant along a ray. You simply go through and evaluate the light transport equation: $$ L_o(p, \omega_o) = L_e(p,\...
- 319
1 vote
0 answers
245 views
Confusion about different sampling strategies in Monte Carlo Path Tracing
I am studying Monte Carlo Path Tracing from different sources. However, I have some confusion about the sampling part and dare to post here for experts' ...
- 135
1 vote
1 answer
74 views
Sampling scattering direction around directions other than the last ray direction
In a path tracer, if we want to sample a ray direction in scattering medium, we can use phase function sampling, which actually use the direction of the ray before sampling as a sort of anchor to ...
- 1,462
1 vote
1 answer
755 views
Importance sampling of the blinn-phong brdf in pathtracing
tl;dr: How do you importance sample the blinn-phong-brdf? Recipe for importance sampling of the phong brdf as far as i understood it (pseudo-code): ...
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