Search found 164 matches

by graphicsMan
Sat Jul 07, 2012 4:34 pm
Forum: General Development
Topic: Discussion about photon mapping.
Replies: 5
Views: 4282

Re: Discussion about photon mapping.

Whether you are better off shooting photons based on uniform or diffuse depends on your emission distribution. Choose what is right for your light sources. I don't know about PBRT's implementation, as I haven't read that chapter, but when I implemented photon mapping a (long) while back, I used Jens...
by graphicsMan
Thu May 31, 2012 4:26 am
Forum: Links & Papers
Topic: Vertex Merging
Replies: 21
Views: 16773

Re: Vertex Merging

Thanks for the reply and for pointing out that tech report.
by graphicsMan
Fri May 25, 2012 2:15 am
Forum: Links & Papers
Topic: Vertex Merging
Replies: 21
Views: 16773

Re: Vertex Merging

So is it possible to use something like the adaptive markov chain idea to drive light paths toward eye paths? I guess you could accept a path only if (a) a vertex was merged, or (b) a non-zero connection can be made?
by graphicsMan
Thu May 24, 2012 8:30 pm
Forum: Links & Papers
Topic: Vertex Merging
Replies: 21
Views: 16773

Re: Vertex Merging

So does this work as well for really hard caustics as SPPM? And how do we choose r? Is there a more in-depth paper than the two page one linked from this thread? Does the technique simply modify SPPM, so r is already defined by that SPPM? Is it easy to make this idea work with the adaptive markov ch...
by graphicsMan
Tue Apr 24, 2012 9:46 pm
Forum: Links & Papers
Topic: Memless RT
Replies: 11
Views: 14654

Re: Memless RT

Neat. What's cool is that this paradigm is pretty new... maybe within a few years it can be made competitive with more traditional approaches. Thanks for sharing.
by graphicsMan
Wed Mar 28, 2012 6:13 pm
Forum: General Development
Topic: Ray differentials and progressive rendering
Replies: 3
Views: 4193

Re: Ray differentials and progressive rendering

I would think that in practice, going smaller than a certain footprint can have no visible benefit. For example, if you computed your differentials on an 8x8 virtual sub-grid for the pixel, I doubt very much that you will see finer detail in your texturing by going to say a 16x16 sub-grid. Just a hu...
by graphicsMan
Sun Mar 04, 2012 4:54 pm
Forum: Visuals, Tools, Demos & Sources
Topic: complex rendering
Replies: 10
Views: 9585

Re: complex rendering

Wow, somehow I really botched my reading of this description. Doh! I thought it said the rendered image was 28kx14k. At 1080p, that's far more reasonable, but still impressive.

Is the sorting/streaming using something similar to Garanzha et al?
by graphicsMan
Sat Mar 03, 2012 5:33 pm
Forum: Visuals, Tools, Demos & Sources
Topic: complex rendering
Replies: 10
Views: 9585

Re: complex rendering

Okay. This is beyond amazing. Just eye rays: 28000*14000*4/0.15 = 10 billion rays per second. If you estimate that with a ray depth of 15 and with exponential increase due to splitting at glass interfaces, we'll go easy and say that the average path length is 10 (probably still on the low side, even...
by graphicsMan
Wed Feb 22, 2012 3:01 pm
Forum: General Development
Topic: Total SAH of a BVH
Replies: 11
Views: 11544

Re: Total SAH of a BVH

It seems to me that you'd want more-or-less an average cost of traversing the tree. If you had this, you could insert the tree as a node into another tree with the SAH :) If you think about this at any given node, it would be Ct + Pl*Cl + Pr*Cr where Ct = node traversal cost Pl = probability of trav...
by graphicsMan
Thu Feb 16, 2012 2:39 pm
Forum: General Development
Topic: Voxel vs BVH
Replies: 9
Views: 7097

Re: Voxel vs BVH

It seems though that the (virtual) grid will need to be extremely fine to capture smooth surfaces unless the cells describe isosurfaces via corner values and gradients; at that point it becomes less cheap too ;) For any real scene you need an adaptive grid, octree, BVH, or kdtree+leaf box to make th...