Search found 13 matches

by bachi
Thu Aug 16, 2018 5:56 am
Forum: GPU
Topic: Is GPU computing dead already?
Replies: 20
Views: 15378

Re: Is GPU computing dead already?

Just want to bring back this thread. It's funny how much has changed in the past 5 years.
by bachi
Sat Jan 21, 2017 6:34 pm
Forum: General Development
Topic: PBRT-v3 (the book) wrong microfacet BTDF?
Replies: 3
Views: 4249

Re: PBRT-v3 (the book) wrong microfacet BTDF?

I guess this is related to the asymmetry of the BTDF (c.f. chapter 5 in Eric Veach's thesis). When evaluating the BTDF as radiance, there is a factor of (eta_o / eta_i)^2 between the transmitted and incident radiance. According to Walter's paper, they treat the BTDF as radiance (see the end of Secti...
by bachi
Tue Oct 25, 2016 7:51 pm
Forum: Links & Papers
Topic: Robust Light Transport Simulation via Metropolised Bidirectional Estimators
Replies: 5
Views: 9000

Re: Robust Light Transport Simulation via Metropolised Bidirectional Estimators

The proposed algorithm shoots and stores one eye path per pixel, and then samples the light path using metropolis sampling, so one light vertex has negligible storage. My best guess is that the NEE isn't strictly necessary, but it speeds things up and helps with stratification. But a guess is all i...
by bachi
Thu Sep 03, 2015 3:19 pm
Forum: General Development
Topic: Combining Path Tracing with MLT
Replies: 2
Views: 4090

Re: Combining Path Tracing with MLT

I'm not sure thresholding would help. MLT already favors bright paths, and allowing mutations to dim paths would reduce the probability of getting stuck in a small region of path space. I think discontinuities would be noticeable as well. I think clamping the geometry-BRDF product as in the VPL ren...
by bachi
Fri Aug 14, 2015 9:25 pm
Forum: General Development
Topic: gradient domain path tracing (GPT)
Replies: 10
Views: 11222

Re: gradient domain path tracing (GPT)

2 days ago I found this online, https://gist.github.com/BachiLi/4f5c6e5a4fef5773dab1 tested it, works pretty well, but my mathematical experience couldn't allow me to modify the resultant poisson reconstruction much. from the results, some how they are matching L2 minimization, how to do L1 minimiz...
by bachi
Thu Jul 02, 2015 11:13 am
Forum: General Development
Topic: pbrt-v3 source code now available
Replies: 23
Views: 21492

Re: pbrt-v3 source code now available

Hello Matt, Really good news! As I see, there is great major features and improvements, congrats! I'll definitely buy a new book! I have a question about code, there you have sampling function for shape(sphere), and in addition you have function for Pdf? What is the reason to separate those two. Pr...
by bachi
Thu Oct 02, 2014 12:44 pm
Forum: General Development
Topic: Questions about metroplis sampling.
Replies: 22
Views: 13106

Re: Questions about metroplis sampling.

One thing I want to ask is why does it use only one markov chain for the entire image, instead of using one chain per pixels. That way we get high quality samples AND equal amount of samples per pixel. Has anyone tried this before? This is exactly what the energy redistribution path tracing paper p...
by bachi
Fri Mar 21, 2014 1:30 am
Forum: General Development
Topic: Efficient sampling of many lights
Replies: 22
Views: 20311

Re: Efficient sampling of many lights

Just to add one thing to ingenious' comment: the correlated error in lightcuts can be reduced by using multiple representatives. See, for example, multi-dimensional lightcuts. I think essentially most many-lights clustering algorithms(e.g. matrix row-colum sampling, lightslice) can be viewed as a st...
by bachi
Mon Mar 10, 2014 3:31 am
Forum: General Development
Topic: Hair intersection : approaches ?
Replies: 16
Views: 11612

Re: Hair intersection : approaches ?

Here are two recent papers on hair rendering, both of them can be implemented on GPU http://fileadmin.cs.lth.se/graphics/research/papers/2012/hairy/ http://kunzhou.net/2013/fur-rendering-tvcg.pdf Both of them intersect the hairs with an aggregate of rays(the former use line and the latter use cone) ...
by bachi
Fri Mar 08, 2013 1:06 am
Forum: General Development
Topic: State of the art of SSS
Replies: 7
Views: 6129

Re: State of the art of SSS

Thanks a lot Stefan, I will review the last paper... I'm just surprised that there is no more (at least not much) research around that :-P Here is a list of some SSS papers we have collected before, I haven't implemented any of them, and I believe the list is not complete, but it might be a good id...

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