Search found 11 matches

by kaplanyan
Wed Sep 03, 2014 12:59 pm
Forum: General Development
Topic: sampling pure specular paths
Replies: 4
Views: 4169

Re: sampling pure specular paths

Hi Mohamed, A very important question indeed. The general problem of finding pure specular paths is tough, as it is equivalent to an arbitrary constraint satisfaction problem, which is proven to be NP-complete (http://en.wikipedia.org/wiki/Complexity_of_constraint_satisfaction). For a practical scen...
by kaplanyan
Fri Sep 20, 2013 3:18 pm
Forum: General Development
Topic: A note on PPM/VCM with specrtal rendering and motion blur
Replies: 9
Views: 7416

Re: A note on PPM/VCM with specrtal rendering and motion blu

...I am not sure if all refractive materials have sharp spectral responses. Do you have any reference? Even if it is the case, having a sharp spectral response itself seems already problematic to handle... Refractive index of real materials usually varies with wavelength, causing different waveleng...
by kaplanyan
Fri Sep 20, 2013 2:30 pm
Forum: General Development
Topic: A note on PPM/VCM with specrtal rendering and motion blur
Replies: 9
Views: 7416

Re: A note on PPM/VCM with specrtal rendering and motion blu

You'd get the whole (noisy) images at fixed wavelengths and fixed shutter time merged with each other. So both motion blur and spectral effects would looks like ghosting of corresponding objects/ illumination features, in spirit of Cook84's distributed ray tracing. Even though such correlation can b...
by kaplanyan
Thu Sep 19, 2013 1:28 pm
Forum: General Development
Topic: A note on PPM/VCM with specrtal rendering and motion blur
Replies: 9
Views: 7416

A note on PPM/VCM with specrtal rendering and motion blur

It is not a secret that kernel estimation decreases the asymptotic convergence rate (in big-O notation). This is also reflected in VCM as a fact that the MIS weight of PPM decreases with the rate \[O(N^{-1/3}),\] indicating that the MSE convergence rate of PPM is slower than the same convergence rat...
by kaplanyan
Mon Feb 25, 2013 6:12 pm
Forum: General Development
Topic: Hard to sample path... BDPT+Refraction+Small area light
Replies: 10
Views: 8904

Re: Hard to sample path... BDPT+Refraction+Small area light

You can also try to consider larger area of light source for such paths. You can use the same technique as in Path Space Regularization, i.e. if it's a pure specular path (so that its probability is very low), you just enlarge the light source e.g. for the last connection. You can also check out the...
by kaplanyan
Tue Feb 12, 2013 1:32 pm
Forum: Links & Papers
Topic: Path Space Regularization
Replies: 12
Views: 11834

Re: Path Space Regularization

Sure, But are you sure that we cannot use MLT with Vertex Merging and that it will produce similar results... but unbiased with the constraint that it is more expensive ? Vertex Connection and Merging never produced unbiased results AFAIK. And the "merging" in the PSR paper is mathematically very s...
by kaplanyan
Tue Feb 12, 2013 1:06 pm
Forum: Links & Papers
Topic: Path Space Regularization
Replies: 12
Views: 11834

Re: Path Space Regularization

I am very interested in this. So what's the conclusion? is this method better than BDPT? VCM? SPPM? The conclusion is that now MLT can also sample some complex light paths, like reflected caustics from point light, prior non-sampleable by unbiased methods. The price for that of course is the bias, ...
by kaplanyan
Mon Jan 28, 2013 12:42 pm
Forum: Links & Papers
Topic: Path Space Regularization
Replies: 12
Views: 11834

Re: Path Space Regularization

Hello all, Thanks a lot for warm replies! Let me address a few questions Maybe my question is whether directional blur has some good properties for the combination with MCMC which spatial blur does not have. Yes, that is a very good question. In the end there is no conceptual (mathematical) differen...
by kaplanyan
Fri Jan 25, 2013 1:02 pm
Forum: Links & Papers
Topic: Path Space Regularization
Replies: 12
Views: 11834

Path Space Regularization

Hello all,

Just in case if someone's interested, here is the new EG2013 paper of mine about how to deal with singularities in the light transport integrand: http://cg.ibds.kit.edu/PSR.php
Hope you'll like it.

Anton
by kaplanyan
Sat Dec 08, 2012 1:51 pm
Forum: Links & Papers
Topic: Vertex merging paper and SmallVCM
Replies: 33
Views: 30865

Re: Vertex merging paper and SmallVCM

tomasdavid wrote:Anton: Have you looked at combining your stuff with VCM?
Not yet. These two ideas were born in parallel. I think the combination with the PPM part of VCM should be straightforward. However one would still need to think about the application to the BDPT part of VCM.