Search found 382 matches

by spectral
Wed Dec 21, 2011 11:01 am
Forum: General Development
Topic: Sampling lights
Replies: 22
Views: 15971

Re: Sampling lights

Imagine you have the following scene : - 1000 lights in a closed box - 1 light out of the box - 1 camera out of the box If you use uniform sampling, you will have a black image ! Because you have 1/1000 chance to sample the right light. So, you need +- 1000 sample to have a correct one. If you are a...
by spectral
Wed Dec 21, 2011 10:07 am
Forum: General Development
Topic: Sampling lights
Replies: 22
Views: 15971

Re: Sampling lights

Very similar to my implementation :-P So, I have also think to use a 'curve' to sample the lights. By example, imagine you have an emitters array, this way struct { int shaderId; int meshStart; int meshCount; } emitter; emitter emitters[10]; // We have 10 emitters here int lightSamplingCurve[10 * 10...
by spectral
Wed Dec 21, 2011 8:28 am
Forum: General Development
Topic: Tangents computation problem
Replies: 11
Views: 10015

Re: Tangents computation problem

I have finally found the problem, it was due to an pre-processing task, a kind of mesh-reorganization where I have miss to reorganize my UVs too !!!!

Thanks for your help...
by spectral
Tue Dec 20, 2011 10:23 pm
Forum: General Development
Topic: Tangents computation problem
Replies: 11
Views: 10015

Re: Tangents computation problem

Yes, of course ... To generate the tangents, I use the code from here : http://www.terathon.com/code/tangent.html I have also try other solutions, but none gives the correct solution ! I think that my problem is to compute the UVs when I only have the normals, because the tangents are computed from ...
by spectral
Tue Dec 20, 2011 12:24 pm
Forum: General Development
Topic: Tangents computation problem
Replies: 11
Views: 10015

Tangents computation problem

Hi, I have a model that I try to render, the problem is that some shaders (diffuse, phong, etc...) use a method based on the 'tangent' to re-orient a vector based on the face orientation. By example, in the diffuse shader I do the following : Lwo = CosineSampleHemisphere2(u1, u2); return LocalToWorl...
by spectral
Tue Dec 20, 2011 7:12 am
Forum: General Development
Topic: Sampling lights
Replies: 22
Views: 15971

Re: Sampling lights

Great,

Also, can you tell us how you do to have a non-uniform sampling of the light sources ? by example if a light source has 2x more power than another one, you sample it 2x more ? once done, how you normalize the contribution ?

How do you do this on the GPU ? Maybe there is an issue ?
by spectral
Mon Dec 19, 2011 2:34 pm
Forum: General Development
Topic: Sampling lights
Replies: 22
Views: 15971

Re: Sampling lights

Interesting subject... in fact there are so much possibles cases :-P Here are some references that I have found, not read yet : https://sites.google.com/site/isrendering/ http://graphics.cs.ucf.edu/gpusampling/ http://sirkan.iit.bme.hu/~szirmay/lightsource.pdf http://www.cs.ubc.ca/~heidrich/Papers/P...
by spectral
Wed Dec 07, 2011 6:05 pm
Forum: ompf2
Topic: Welcome!
Replies: 32
Views: 37519

Re: Welcome!

Or renderdev.org (like gamedev etc...), by example ;-)
by spectral
Wed Dec 07, 2011 3:32 pm
Forum: ompf2
Topic: Welcome!
Replies: 32
Views: 37519

Re: Welcome!

Yes, but there are some other available domains... honnestly I don't understand what mean 'ompf' and maybe there are better name than this one.

Of course, if the original one can be back, its better, also because there are a lot of interesting discussions :-P
by spectral
Tue Dec 06, 2011 9:15 am
Forum: ompf2
Topic: Welcome!
Replies: 32
Views: 37519

Re: Welcome!

Just a question

What mean OMPF ? it's a strange name... maybe the best will be to register a new domain and host it on one of our servers ?

We can also share the administration to some 'top level' users like Jacco, toxie etc....