Search found 82 matches

by friedlinguini
Thu Jun 27, 2013 3:53 pm
Forum: My First...
Topic: Low-discrepancy samplers
Replies: 17
Views: 18590

Re: Low-discrepancy samplers

2. (sample the image plane) dimension 0 & dimension 1 for generating the pixel index (basically: pixelX = width * dim[0]; pixelY = height * dim[1];) 3. dimension 2 & dimension 3 for jittering the sample within the pixel Why do you need two steps for this? Why not float fPixelX = width * dim...
by friedlinguini
Mon Jun 24, 2013 7:25 pm
Forum: My First...
Topic: Low-discrepancy samplers
Replies: 17
Views: 18590

Re: Low-discrepancy samplers

Thank you, friedlinguini! That tiny-bit clears things up - but what about, say, stratified sampling? What corresponds to sampling dimension in stratified sampling? I mean, with Halton/Sobol one uses ever higher primes with every light bounce - but in case of stratified sampling..what do the stratas...
by friedlinguini
Mon Jun 24, 2013 2:13 pm
Forum: My First...
Topic: Low-discrepancy samplers
Replies: 17
Views: 18590

Re: Low-discrepancy samplers

Also, why does the SobolGenerator uses so many dimensions (32)? I understand that there might be some case where one needs so high dimensions (like in statistics) but for path-tracing it is way less, no? I mean, I try to use only two (for hemisphere sampling), another two could be used for antialia...
by friedlinguini
Mon May 27, 2013 2:11 pm
Forum: General Development
Topic: artifacts - any idea
Replies: 15
Views: 8776

Re: artifacts - any idea

sajis997, I mean that the caustic is much more visible. I personally think that's a good thing.

yiningkarlli, in the image identified as the "direct lighting only" image (http://imgur.com/EdZ0yza) there is a visible diffuse component to the material.
by friedlinguini
Thu May 16, 2013 11:55 am
Forum: General Development
Topic: artifacts - any idea
Replies: 15
Views: 8776

Re: artifacts - any idea

It looks OK to me. I also note that your elephant has a more pronounced caustic. More importantly, what do you think?
by friedlinguini
Mon May 13, 2013 5:16 pm
Forum: General Development
Topic: artifacts - any idea
Replies: 15
Views: 8776

Re: artifacts - any idea

In a pinch, I think if(generated random number < refractivity coefficient) { Get a refracted ray. refractedColor = trace(refracted ray, depth -1, 1 /* formerly 0 */); } else if(generated random number < reflectivity coefficient) { Get the reflected ray. reflectedColor = trace(reflected ray, depth - ...
by friedlinguini
Thu May 09, 2013 8:49 pm
Forum: General Development
Topic: artifacts - any idea
Replies: 15
Views: 8776

Re: artifacts - any idea

OK, let me put it this way. It looks to me like you're not getting a specular reflection of the light source in the mirror ball. That is, LSE paths (light -> mirror -> eye) are not showing up in your rendering. LDSE paths are showing up (light -> ceiling -> mirror ->eye), so you wind up with a dark ...
by friedlinguini
Thu May 09, 2013 7:01 pm
Forum: General Development
Topic: artifacts - any idea
Replies: 15
Views: 8776

Re: artifacts - any idea

Given that, along with the fact that the specular materials are effectively removed from your direct lighting calculations, wouldn't ... else if(generated random number < reflectivity coefficient) { Get the reflected ray. reflectedColor = trace(reflected ray, depth - 1, 0); } mean no specular highli...
by friedlinguini
Thu May 09, 2013 4:20 pm
Forum: General Development
Topic: artifacts - any idea
Replies: 15
Views: 8776

Re: artifacts - any idea

When computing indirect illumination, what happens when one of your secondary rays from a diffuse material happens to hit a light source? Is it possible that you are doubling up on your direct illumination? One quick experiment might be to double the intensity of your light source, omit direct illum...
by friedlinguini
Wed May 08, 2013 12:46 pm
Forum: General Development
Topic: artifacts - any idea
Replies: 15
Views: 8776

Re: artifacts - any idea

Offhand it looks like your LSE (possibly LS(S|D)*E) paths are broken. How are you calculating direct lighting on specular surfaces? If you're doing explicit connections to the light source (e.g., picking a point on the source, casting a shadow ray, and evaluating the BSDF), then the specular compone...

Go to advanced search