Search found 46 matches

by apaffy
Wed Apr 18, 2012 10:13 am
Forum: Visuals, Tools, Demos & Sources
Topic: embree+OSL+alembic
Replies: 10
Views: 12684

Re: embree+OSL+alembic

Nice image and great performance! How easy is it to integrate OSL into a project? I currently have my own extremely basic shader/closure system, but I would be interested in checking out OSL if it is simple to set up. And more random question: it seems that the main target of OSL is x86, has anyone ...
by apaffy
Thu Mar 22, 2012 8:55 pm
Forum: General Development
Topic: Nvidia limiting gtx680 compute speed?
Replies: 20
Views: 17479

Re: Nvidia limiting gtx680 compute speed?

Wow unexpected benchmark result. Makes a GTX 580 look a lot more tempting if the price can come down a bit.
by apaffy
Wed Mar 21, 2012 7:06 pm
Forum: General Development
Topic: MIS question
Replies: 16
Views: 11456

Re: MIS question

It is small optimization introduced a while ago over standard PBRT code. MiS has a cost, it requires to trace 2 shadow rays instead of one. Just for completeness, it does indeed have a cost if you are only trying to solve direct lighting, but if you are implementing a path tracer and you're going t...
by apaffy
Wed Mar 21, 2012 3:40 pm
Forum: General Development
Topic: MIS question
Replies: 16
Views: 11456

Re: MIS question

So, it seems that they only use MIS if you hit a non-diffuse surface. It looks interesting but if someone know why ? Or maybe it is the inverse, we don't use MIS for specular surfaces ! You can only multiple importance sample between valid sampling techniques. If your BSDF is specular, you can't sa...
by apaffy
Sat Jan 07, 2012 2:52 pm
Forum: General Development
Topic: Bidirectional related question
Replies: 7
Views: 5591

Re: Bidirectional related question

This is just a question of units isn't it? Flux (specifically radiant flux) is the total power of the light measured in Watts. Radiance is power per unit area per unit projected solid angle. Example: consider a uniform light source of area 3m^2 with flux 10W. Each point of the light source emits uni...
by apaffy
Sun Jan 01, 2012 5:32 pm
Forum: General Development
Topic: Preetham Sun, spectral rendering
Replies: 15
Views: 11613

Re: Preetham Sun, spectral rendering

Also beware of the paper errata: in appendix A1 in the equations for tor_{r,gamma} and tor_{a,gamma} the relative optical mass m should be part of the product for the power of e, not the power of gamma. This is fixed in the example code provided with the paper, and in the Optix SDK example too, so I...