Search found 83 matches

by MohamedSakr
Sun Jun 15, 2014 1:41 pm
Forum: General Development
Topic: multiple reference octree OR BVH for GPU?
Replies: 0
Views: 6766

multiple reference octree OR BVH for GPU?

I want to implement a good acceleration data structure for ray-triangle intersections into my GPU raytracer
I heard that "multiple reference octree" got a very good performance, is it better than BVH? (in terms of memory consumption and parallel)

if so, any paper or implementation?
by MohamedSakr
Tue Jun 10, 2014 2:41 pm
Forum: General Development
Topic: Color space: when to multiply by the matrix
Replies: 13
Views: 9190

Re: Color space: when to multiply by the matrix

It still feels weird though, since usually when working with different unit systems, things cancel out or contains squared dimensions. here is a simple example, when you get the reflected ray color which case do you calculate: Color2 C = Color A * Color B; or Color C = Color A * Color B; where A is...
by MohamedSakr
Wed Jun 04, 2014 11:35 pm
Forum: General Development
Topic: Color space: when to multiply by the matrix
Replies: 13
Views: 9190

Re: Color space: when to multiply by the matrix

Now let's assume I want to 'render in' another linear colour space, B. As far as I know, there is a 3x3 (number of RGB components) matrix going from A to B, which we will call AtoB. It seems like I have to ways to 'render in the colour space B': - doing my render as previously, then multiply the ou...
by MohamedSakr
Tue Jun 03, 2014 9:52 pm
Forum: General Development
Topic: VCM GPU implementation (+ some extras)
Replies: 8
Views: 8396

Re: VCM GPU implementation (+ some extras)

@Dietger really nice thesis :D , what I see "I may be mistaken so correct me" is that you put the whole camera loop inside the light loop, is this safe to do in smallVCM? "as there is photons merging (ppm)", I see the main benefit here is the memory consumption, why it is GPU friendly? "I sense it s...
by MohamedSakr
Mon Jun 02, 2014 11:39 am
Forum: General Development
Topic: VCM GPU implementation (+ some extras)
Replies: 8
Views: 8396

Re: VCM GPU implementation (+ some extras)

about sorting: in this loop "for(;; ++lightState.mPathLength)" and "for(;; ++cameraState.mPathLength)" I can sort 2 times per iteration, 1 for BSDF (each BSDF is interacting in a different way, and lots of checks about BSDF.isdelta() or BSDF.isvalid() etc... and 1 at the end for sample Scattering "s...
by MohamedSakr
Sun Jun 01, 2014 11:07 am
Forum: General Development
Topic: VCM GPU implementation (+ some extras)
Replies: 8
Views: 8396

VCM GPU implementation (+ some extras)

I'm trying to implement VCM (from SmallVCM project) to GPU using CUDA, I've read "Progressive Light Transport Survey on the GPU: Survey and Improvements" I have a few questions: 1- in the light samples loop, should I sort every light bounce iteration? (to avoid divergence within warps), I've tested ...
by MohamedSakr
Sun May 18, 2014 9:25 pm
Forum: General Development
Topic: UPS vs VCM?
Replies: 9
Views: 6531

Re: UPS vs VCM?

You need ConnectToCamera for paths that have a flag that the previous interaction was purely specular. I believe we have a flag like that already in, but cannot check now. If we don't, then adding one should be fairly trivial. That gives you caustics as EDS(anything) yes I have noticed this and sol...
by MohamedSakr
Sun May 18, 2014 3:22 pm
Forum: General Development
Topic: UPS vs VCM?
Replies: 9
Views: 6531

Re: UPS vs VCM?

in smallVCM, I'm trying to "catch" only caustics, but couldn't find out how, I tried to output ConnectToCamera() only, but the result is all photons "not only caustics", what am I missing there to classify photons?
by MohamedSakr
Sat May 03, 2014 8:22 pm
Forum: General Development
Topic: help with Robust Image Denoising using a Virtual Flash Image
Replies: 1
Views: 3261

help with Robust Image Denoising using a Virtual Flash Image

I'm trying to implement "Robust Image Denoising using a Virtual Flash Image for Monte Carlo Ray Tracing" , I've successfully implemented the denoising algorithm, but still having some trouble with generating the flash image itself!! paper url, http://sglab.kaist.ac.kr/VFL/ here is the result for 16 ...
by MohamedSakr
Wed Apr 30, 2014 3:35 pm
Forum: General Development
Topic: UPS vs VCM?
Replies: 9
Views: 6531

Re: UPS vs VCM?

Perhaps in that last case you could benefit from "Robust Adaptive Photon Tracing using Photon Path Visibility". looks like a decent approach!!, so I should replace Mis with AMCMCPPM sampler? ....or simpler methods based on prior analysis of the scene (with simple photon shooting for instance) and w...