Search found 9 matches

by patlefort
Tue Jul 11, 2017 1:59 am
Forum: General Development
Topic: MIS with IBL
Replies: 14
Views: 2394

Re: MIS with IBL

Re-reading your first comment, you say that another light may be visible when sampling the sky. When you select the sky, you have to shoot a shadow ray just like any other light source. If that shadow ray is occluded by another light source, it must not contribute anything, because it's the sky bein...
by patlefort
Sat Jul 08, 2017 11:04 pm
Forum: General Development
Topic: MIS with IBL
Replies: 14
Views: 2394

Re: MIS with IBL

When your ray stumble upon a light source and you want to do MIS, you need to know the probability of it being selected. It's impossible to know that probability without having sampled random points on all other light sources in your sampling method. I'm not sure if doing that make sense and will co...
by patlefort
Thu Apr 20, 2017 5:20 am
Forum: Visuals
Topic: Glitch Pictures anyone?
Replies: 74
Views: 76474

Re: Glitch Pictures anyone?

Image

Fail trying to use sobol sequences with bidirectional path-tracing.
by patlefort
Wed Sep 14, 2016 6:02 am
Forum: Visuals
Topic: Bi-layer, anistropic, multi-scattering microfacets
Replies: 3
Views: 10986

Re: Bi-layer, anistropic, multi-scattering microfacets

Coincidentally I was looking at the problem of layers in the last few days trying to improve clear coating. It's possible to account exactly the amount of light reflected by the bottom layer if you assume that the light will hit the same microfacet always, just like you can do with a thin glass mate...
by patlefort
Mon Sep 12, 2016 8:57 am
Forum: Visuals
Topic: Bi-layer, anistropic, multi-scattering microfacets
Replies: 3
Views: 10986

Re: Bi-layer, anistropic, multi-scattering microfacets

Nice renders :)

I'm curious by what do you mean by bi-layer, multi-scattering microfacet model?

Is it GPU or CPU?
by patlefort
Thu Jul 14, 2016 5:42 pm
Forum: Visuals
Topic: Glitch Pictures anyone?
Replies: 74
Views: 76474

Re: Glitch Pictures anyone?

It's possible to not fail affine transformation for a sphere if you transform the ray into the local coordinate of the sphere.
by patlefort
Fri Jul 01, 2016 8:58 am
Forum: Tools, Demos & Sources
Topic: Direct Light Integration using MIS
Replies: 11
Views: 8220

Re: Direct Light Integration using MIS

Small typo in the code: search for salmpleLight.
by patlefort
Thu Oct 29, 2015 8:02 am
Forum: General Development
Topic: Basic question: material that will change the normal
Replies: 3
Views: 5502

Re: Basic question: material that will change the normal

You definitely need to calculate it before doing any shading calculation as they should be based on this normal. You should keep a copy of the surface real geometric normal along side and use that to displace the starting position of rays to avoid self-intersection.
by patlefort
Sun Jul 12, 2015 4:54 am
Forum: General Development
Topic: Float versus double
Replies: 12
Views: 9287

Re: Float versus double

I would use float unless you have specific needs for the precision of doubles. With floats, you can fit a vertex inside a single SSE register or you can perform 2x more operations at the same time. It'd be great if one day we can use doubles without worry but for now it's not worth the performance l...

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