Search found 408 matches

by CodeHD
Wed Nov 25, 2020 12:44 pm
Forum: Development
Topic: exr image output
Replies: 24
Views: 3979

Re: exr image output

No, the factor 0.39 was the ratio between the scale factors for different gamma, not the scale factor itself. At gamma 2.2, this evaluates to 2.465e-4.
by CodeHD
Wed Nov 25, 2020 12:09 pm
Forum: Development
Topic: exr image output
Replies: 24
Views: 3979

Re: exr image output

So to get the same result I have to map maximum value in exr to 1 and after this apply gamma correction. You might still not end up with exactly the same result as the LuxCore output, because LuxCore doesn't apply normalisation but a scaling factor that depends on gamma. (Normalisation doesn't real...
by CodeHD
Tue Nov 24, 2020 6:50 pm
Forum: Development
Topic: Disney BRDF material
Replies: 122
Views: 33116

Re: Disney BRDF material

Be careful, Cycles has extend Disney material in multiple way including using no GGX model for micro-facets (something never even vaguely mentioned by Disney people). Do you refer to the "Multiscatter - GGX" ? I ask this because I only see two models in the cycles principled shader, GGX and Multisc...
by CodeHD
Tue Nov 24, 2020 6:33 pm
Forum: User Support
Topic: strange behaviour of homogeneous scattering volume
Replies: 17
Views: 2992

Re: strange behaviour of homogeneous scattering volume

Little addendum: I realised the sample is a bit darker than the background because I left the path depth at the default value of 6, so that a small Fresnel-reflection part is not traced. (Gamma correction then amplifies it.) So just increase the total and specular path depth a little and the result ...
by CodeHD
Tue Nov 24, 2020 10:08 am
Forum: User Support
Topic: strange behaviour of homogeneous scattering volume
Replies: 17
Views: 2992

Re: strange behaviour of homogeneous scattering volume

On this pictures you may see that the sample plate is almost specular: Exactly: almost ;) Your choice of normal map seems to be quite a good match. Attached is your scene back with three changes: Clear Volume instead of Homogeneous. (The effect really comes form the surface alone. You can add some ...
by CodeHD
Mon Nov 23, 2020 4:20 pm
Forum: User Support
Topic: strange behaviour of homogeneous scattering volume
Replies: 17
Views: 2992

Re: strange behaviour of homogeneous scattering volume

I've continued the investigation of the scatter volume and all the tests I've done share also one irregularity. The render results doesn't look blurry. It always appears like there's a colour fade out only with the growth in material thickness: This is a photo of the material that is like imitate: ...
by CodeHD
Mon Nov 23, 2020 4:18 pm
Forum: Development
Topic: Disney BRDF material
Replies: 122
Views: 33116

Re: Disney BRDF material

Yes, given how much I already started reading into this topic I can try to do it. The Moana-article you linked seems to describe 2015 as well, so there is example code. It also already provided me with some explanation for questions I had from the current LuxCore implementation. I have briefly looke...
by CodeHD
Sun Nov 22, 2020 9:54 pm
Forum: Development
Topic: Disney BRDF material
Replies: 122
Views: 33116

Re: Disney BRDF material

Thanks for the quick response Dade! The wonderful world scientific papers, 90% is just ru**ish, the other 9% may be interesting but they don't provide even half of the required information, the 1% is done right. Providing sample code should be the bare minimum requirement to publish a paper. Strictl...
by CodeHD
Sun Nov 22, 2020 8:52 pm
Forum: Development
Topic: Disney BRDF material
Replies: 122
Views: 33116

Re: Disney BRDF material

I'm also checking a bit the code because some of the outputs doesn't look right to me. I'm digging out some old stuff here, but I'd like to ask if you remember what these outputs were back then that you investigated? Was it just the things discussed in this thread like front-backside or the specula...
by CodeHD
Sun Nov 22, 2020 7:43 pm
Forum: User Support
Topic: Specular reflection vs diffuse reflection.
Replies: 21
Views: 2975

Re: Specular reflection vs diffuse reflection.

Could you perhaps clarify what your ultimate goal is? Both w.r.t. this thread as well as your test setup in general. Upon re-reading your first post, it sounds like you ware aware of this problem first, and now built it specifically to experimentally verify it. Is that correct or was it built for an...