Search found 6 matches

by necro
Fri Aug 23, 2013 5:05 pm
Forum: General Development
Topic: Dielectric BRDFs
Replies: 6
Views: 5296

Re: Dielectric BRDFs

I should clarify; the problem isn't energy conservation. It's finding a balance between specular and diffuse reflection. I realize that the Phong model isn't exactly physically based, but what's a good balance between them? Isn't it angle-dependent? Also, I'm trying to premultiply any Fresnel coeff...
by necro
Thu Feb 21, 2013 9:53 pm
Forum: General Development
Topic: Volume Transmittance in Heterogeneous Media
Replies: 6
Views: 4952

Re: Volume Transmittance in Heterogeneous Media

Secret sources tell me that the first author is in league with dark forces and that the algorithm might be verbal inspiration by Satan himself :twisted: But that's surely no excuse for a badly written paper. Let's try an exorcism. The idea behind the algorithm is to only create starting points for t...
by necro
Sat Aug 11, 2012 2:40 am
Forum: General Development
Topic: MLT - how difficult is it?
Replies: 11
Views: 7708

Re: MLT - how difficult is it?

the course notes and slides will be featured on https://sites.google.com/site/qmcrendering/

it's still in the process of being put together, but I would guess you should see things appearing there in the next two weeks
by necro
Fri Jun 29, 2012 10:09 pm
Forum: Visuals, Tools, Demos & Sources
Topic: Some clouds
Replies: 9
Views: 12615

Re: Some clouds

yeah, clouds! this is far more on the physical side than the stuff I do for clouds (I basically only create "artistic" procedural volume data that is evaluated on the fly in my volume path tracer). Thanks for sharing, it gave me a few interesting pointers to more material on the topic!! Clouds are a...
by necro
Thu Jun 21, 2012 7:20 pm
Forum: Visuals, Tools, Demos & Sources
Topic: Glitch Pictures anyone?
Replies: 81
Views: 118806

Re: Glitch Pictures anyone?

numerically unstable cloud layer intersection
Image
by necro
Thu Dec 22, 2011 9:59 am
Forum: General Development
Topic: Preetham Sun, spectral rendering
Replies: 15
Views: 11740

Re: Preetham Sun, spectral rendering

a) be careful about the sun radiance data in Preetham paper, I think of by a factor (10 times too low if I remember correctly) w.r.t. the units cited in the paper. Compare it to other sources. b) In general I recommend "Wyszecki & Stiles - Color science", if you can gain acces to that book. For the ...