Search found 164 matches

by graphicsMan
Tue Jul 17, 2012 5:27 pm
Forum: General Development
Topic: Veach thesis - formula question
Replies: 86
Views: 49164

Re: Veach thesis - formula question

graphics to debug graphics... I'll +1 my vote for that approach.
by graphicsMan
Mon Jul 16, 2012 12:57 pm
Forum: General Development
Topic: Veach thesis - formula question
Replies: 86
Views: 49164

Re: Veach thesis - formula question

Wow, I was starting to wonder if physics had changed. I don't even understand what the light_dir direction is supposed to represent?
by graphicsMan
Sat Jul 14, 2012 2:26 pm
Forum: Links & Papers
Topic: Surface area of polytopes
Replies: 5
Views: 5271

Re: Surface area of polytopes

sent pm...
by graphicsMan
Fri Jul 13, 2012 5:14 pm
Forum: General Development
Topic: Approximate dispersion with RGB & local filtering
Replies: 5
Views: 4516

Re: Approximate dispersion with RGB & local filtering

You could use single-wavelength samples...
by graphicsMan
Fri Jul 13, 2012 12:46 pm
Forum: General Development
Topic: Approximate dispersion with RGB & local filtering
Replies: 5
Views: 4516

Re: Approximate dispersion with RGB & local filtering

16 bands actually works fairly well from my past experience...
by graphicsMan
Fri Jul 13, 2012 12:44 pm
Forum: Links & Papers
Topic: Surface area of polytopes
Replies: 5
Views: 5271

Re: Surface area of polytopes

You can keep around the areas of the faces that aren't split, and there are optimizations you can make to get the new surface areas of the split faces. However, I don't know of any super-fast formulas for knowing the SA from just the implicit (slab) representation of the k-DOP. You can find some det...
by graphicsMan
Sun Jul 08, 2012 1:03 pm
Forum: General Development
Topic: Discussion about photon mapping.
Replies: 5
Views: 4281

Re: Discussion about photon mapping.

A regular diffuse area light will have a uniform distribution. However, due to the projected solid angle calculation, there is a cosine term, which means that you'll converge faster if you draw samples on a cosine distribution.
by graphicsMan
Sat Jul 07, 2012 10:59 pm
Forum: General Development
Topic: About low-discrepancy sequence and image filters in ray trac
Replies: 6
Views: 4577

Re: About low-discrepancy sequence and image filters in ray

But won't you have to be more careful with your low-discrepancy sequences? Or does Manfred's paper cover LDSs? Seems like you'd need randomized QMC if you want to do importance sampling of filters?
by graphicsMan
Sat Jul 07, 2012 9:33 pm
Forum: General Development
Topic: About low-discrepancy sequence and image filters in ray trac
Replies: 6
Views: 4577

Re: About low-discrepancy sequence and image filters in ray

Not really "necessary". Try it first with a box filter, since it is zero extra implementation. If you need better filtering, you should be able to use the sequence to pull samples from a b-spline filter without too much effort.
by graphicsMan
Sat Jul 07, 2012 4:56 pm
Forum: General Development
Topic: Tedious bugs in my bidirectional path tracer.
Replies: 10
Views: 10637

Re: Tedious bugs in my bidirectional path tracer.

just take a larger number of samples and then average all the samples in the image.