Search found 11 matches

by josh247
Mon Jul 23, 2018 11:01 am
Forum: General Development
Topic: Emissive surfaces and visibility term
Replies: 6
Views: 578

Re: Emissive surfaces and visibility term

Intuitively speaking the importance of the path from the camera is spread out when projected onto the emitting surface, but this is cancelled out by a larger surface area emitting light. So my understanding is that you can include the term, but this will just be defining a non uniform directional di...
by josh247
Mon Feb 12, 2018 7:59 pm
Forum: Tools, Demos & Sources
Topic: Basis Construction with Tangent Vector
Replies: 0
Views: 730

Basis Construction with Tangent Vector

Wanted to post this simple example for constructing an orthonormal basis that takes two vectors, and uses SIMD instructions. There are a couple of great papers (http://jcgt.org/published/0006/01/01/ and http://jcgt.org/published/0006/01/02/) on the subject which came out recently. These however just...
by josh247
Sun May 07, 2017 11:10 pm
Forum: Tools, Demos & Sources
Topic: Implementation for Blue-noise Dithered Sampling
Replies: 26
Views: 13696

Re: Implementation for Blue-noise Dithered Sampling

Just to clarify, here the implementation (as described in the paper) computes the blue-noise mask using a distance over wrapped boundaries. If this is not required then it's a rather simple change to alter this behavior. On another note, I've recently added some progress feedback in the terminal as ...
by josh247
Wed Feb 01, 2017 11:37 pm
Forum: Tools, Demos & Sources
Topic: Implementation for Blue-noise Dithered Sampling
Replies: 26
Views: 13696

Re: Implementation for Blue-noise Dithered Sampling

Would be interesting to hear your experiences when rendering with it, when optimizing for this 10D case. Cause IMHO the scheme should fall apart when using a large number of dimensions. Indeed, in my experience it's hard (impossible?) to achieve high-quality blue noise in high dimensions :( I'd ima...
by josh247
Wed Feb 01, 2017 11:20 pm
Forum: Tools, Demos & Sources
Topic: Implementation for Blue-noise Dithered Sampling
Replies: 26
Views: 13696

Re: Implementation for Blue-noise Dithered Sampling

Good catch on that instruction toxie, I've pushed up a fix for this. I'd not thought about MSVC support but it's a good point, this should also be working now. Although saying that, I've not got a windows environment to test this on. So if anyone does, and tries compiling the source, then let us kno...
by josh247
Sun Jan 29, 2017 8:23 pm
Forum: Tools, Demos & Sources
Topic: Implementation for Blue-noise Dithered Sampling
Replies: 26
Views: 13696

Re: Implementation for Blue-noise Dithered Sampling

I'll run the program tomorrow at a resolution of 128x128 and record the simulation time. I've not done this yet as the implementation here isn't (and does not claim to be) the same as the one found in the original paper :) There was a sizable performance gain when using AVX2 instructions, but this w...
by josh247
Wed Jan 25, 2017 10:56 pm
Forum: Tools, Demos & Sources
Topic: Implementation for Blue-noise Dithered Sampling
Replies: 26
Views: 13696

Re: Implementation for Blue-noise Dithered Sampling

Unfortunately I've not got any rendered images to share, but it shouldn't be too hard to implement. When the values are written out to the data file they are converted to an unsigned 32bit integer range. This is so that a toroidal shift can easily be applied (to particular sampling patterns) with a ...
by josh247
Sun Jan 22, 2017 7:30 pm
Forum: Tools, Demos & Sources
Topic: Implementation for Blue-noise Dithered Sampling
Replies: 26
Views: 13696

Implementation for Blue-noise Dithered Sampling

Just sharing this implementation for sample mask construction required in the SIGGRAPH 2016 paper "Blue-noise Dithered Sampling" by Iliyan Georgiev and Marcos Fajardo. You can access the paper here: https://www.solidangle.com/arnold/research As there didn't appear to be a strict implementa...
by josh247
Thu Aug 06, 2015 11:15 am
Forum: General Development
Topic: cosine lobe sampling PDF
Replies: 11
Views: 12126

Re: cosine lobe sampling PDF

I hadn't realised there had been anymore responses to this thread. That answered my question completely and you were right in thinking that my original results were incorrect. Cheers for the help guys.
by josh247
Thu Apr 02, 2015 1:19 pm
Forum: General Development
Topic: cosine lobe sampling PDF
Replies: 11
Views: 12126

Re: cosine lobe sampling PDF

Thanks for response koiava although I'm referring to to Monte Carlo sampling distribution rather than the BRDF and maintaining energy conservation (although your statement about 1 / Pi being the normalization factor is still relevant). Currently I have for example a microfacet material that respects...

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