Search found 24 matches

by dawelter
Sun Jul 15, 2018 6:38 pm
Forum: Visuals
Topic: My little path tracer
Replies: 16
Views: 4949

Re: My little path tracer

Went for a pretty low hanging fruit: Importance sampled hdr skydomes! :)
hdrskydome.jpg
hdrskydome.jpg (250.73 KiB) Viewed 3 times
by dawelter
Tue Jul 10, 2018 7:49 am
Forum: Visuals
Topic: My little path tracer
Replies: 16
Views: 4949

Re: My little path tracer

Meanwhile I switched to Embree. Now the renderer feels quite a bit faster. I didn't measure because my data structures had to go out of principle because they were so bad. :lol: Still have something to do about the mess I made with mixed double and float calculations that I now have ... But things s...
by dawelter
Tue Jul 10, 2018 7:36 am
Forum: Visuals
Topic: My first Supersize-Image
Replies: 3
Views: 2219

Re: My first Supersize-Image

Oh yeah! I envy the amount of cool rendering fu you implemented! :-)
by dawelter
Tue Apr 24, 2018 8:49 pm
Forum: Visuals
Topic: My little path tracer
Replies: 16
Views: 4949

Re: My little path tracer

I haven't had implemented a refractive material till now. That needed to be rectified badly.

RefractiveCaustics.jpg
RefractiveCaustics.jpg (244.13 KiB) Viewed 773 times

Not too shabby, I suppose.

(Although, since SDS paths are not rendered, parts are missing. I.e. in lower row, areas behind the glass. And top right, the beam behind the glass.)
by dawelter
Mon Apr 23, 2018 6:33 am
Forum: General Development
Topic: Veach - refractive BTDF adjoint
Replies: 0
Views: 611

Veach - refractive BTDF adjoint

Hello! I'm trying to understand Veach's derivation of the adjoint of the specular refractive BTDF. It seems I hit a brick wall. Some of that stuff looks like black magic to me. Specifically, there is a relation for differential solid angle on the following page: non-symmetry-due-to-refraction.png Wh...
by dawelter
Fri Apr 20, 2018 7:44 am
Forum: Visuals
Topic: My little path tracer
Replies: 16
Views: 4949

Re: My little path tracer

Thank you beason! Actually there was a bug. I wrongly assumed that pdfs for BSDF sampling are symmetric which they are clearly not. p(wi,wo) = p(wo,wi)? No! no! Ah well, how does one say, assumptions are the mother of all f'ups. I finally realized my mistake when ... I implemented statistical tests ...
by dawelter
Sat Mar 24, 2018 8:38 am
Forum: Visuals
Topic: My little path tracer
Replies: 16
Views: 4949

Re: My little path tracer

I threw a "real world" scene at it. Thinking about how else I could exploit volume caustics in lack of refractive materials, I figure it would be cool to build a solar thermal power plant model. :-D Modelled in Stud.io and Cinema 4D. 677761 Triangles, most of them occluded due to the brick...
by dawelter
Wed Mar 21, 2018 1:26 pm
Forum: General Development
Topic: Spectral tracking question
Replies: 6
Views: 1236

Re: Spectral tracking question

Cool! And thanks for the link to the paper. Very interesting. Do you think it is possible to modify closed-form tracking in such a way that it handles spectrally refined absorption/scattering for homogeneous media correctly? For homogeneous media you have the analytic expression for the transmittanc...
by dawelter
Mon Mar 19, 2018 8:25 am
Forum: General Development
Topic: Spectral tracking question
Replies: 6
Views: 1236

Re: Spectral tracking question

Do you think this looks reasonable? Not sure. The method is pretty noisy, indeed. I actually wonder how you get your reference image so clear with jut 16 spp. Try the weighting scheme from "5.1.2 Incorporating Path History". It should reduce the noise somewhat. I spot one error: - t is up...
by dawelter
Sat Mar 17, 2018 3:09 pm
Forum: General Development
Topic: Spectral tracking question
Replies: 6
Views: 1236

Re: Spectral tracking question

Hi, 1. The data is homogeneous, so null collisions don't play a role at the moment I think this is incorrect w.r.t. spectral tracking. Because mu^bar = max_lambda { mu_t(lambda) }, you get mu_n = mu^bar - mu_t > 0 for some lambda if not all mu_t(lambda) are equal. Moreover, the weights are multiplie...

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