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Re: Disney BRDF material

Posted: Fri Jun 07, 2019 3:03 pm
by B.Y.O.B.

Re: Disney BRDF material

Posted: Fri Jun 07, 2019 3:41 pm
by sarmath
Thanks for your help guys...its working now :)

Re: Disney BRDF material

Posted: Fri Jun 07, 2019 4:04 pm
by Sharlybg
Is there anyway to get the old build package model. I mean lastest blendluxcore bundle with lastest correct luxcore so anyone can download a simple single package that can be installed as normal blendluxcore builds.

This will simplify download and install fresh build and increase the number of beta testor and help accelerate development i think.

Re: Disney BRDF material

Posted: Fri Jun 07, 2019 4:13 pm
by B.Y.O.B.
The current situation is: if you want a pre-made build that is easily installed, you have to wait for the next alpha/beta release.
If you want the bleeding edge, you have to read the first three posts here: viewtopic.php?f=9&t=736#p7617 and in general do a few more clicks and stay up to date with recent development (e.g. the opening of the 2.79 branch).

What I would find cool would be an Azure script that creates a new BlendLuxCore daily build whenever:
a) a LuxCore daily build is published
b) a commit is pushed to the BlendLuxCore repo
But it would be a bit of work + requires knowledge of Azure scripts (which I don't have at the moment).

Re: Disney BRDF material

Posted: Fri Jun 07, 2019 4:31 pm
by kintuX
Found Disney's Specular value rendered with OCL a bit brighter than CPU/BiDiR.

Note: Only blue material. Difference shown in yellow.
Although there's a small difference in Glossy too (Red material, Dif. in Blue)

Raw @ 128 samples
BiDir
Disney_BiDir.png
CPU
Disney_CPU.png
OCL
Disney_OCL.png
CPU - OCL Difference
Disney_OCL-CPU(Difference).png

Re: Disney BRDF material

Posted: Fri Jun 07, 2019 4:33 pm
by epilectrolytics
Dade wrote: Fri Jun 07, 2019 2:24 pm Side note

There is a theoretical advantage in using disney BRDF for all materials in a scene when rendering on GPUs: lack of threads divergence. In theory GPUs while evaluate a lot faster a scene where each hit point requires to run the same material code (threads can run the code in parallel instead of having to serialize the execution of divergent code).

It would be interesting to do some test with a scene using many LuxCore materials and the same scene using only the LuxCore Disney material to check if there is a real advantage on GPUs or not.
Good news:
My test scene renders faster indeed with all materials on Disney shader and PathOCL GPU!
Dny.gif
.
Bad news:
When trying to render with PGI indirect cache + Disney materials Blender crashes or I get a black render with a console warning: nothing is visible and/or cache enabled :cry:
(edit: scene link removed because error identified.)
Also I noticed unlike matte or glossy Disney material is one sided = black on the back side.

Re: Disney BRDF material

Posted: Fri Jun 07, 2019 4:37 pm
by Sharlybg
Found Disney's Specular value rendered with OCL a bit brighter than CPU/BiDiR.

Note: Only blue material. Difference shown in yellow.
Although there's a small difference in Glossy too (Red material, Dif. in Blue)
There is a huge specularity dif between your render test :shock: . Bidir is far less specular while OCl GPU is like adding another coating layer. and simple CPU is like a mix of them.

Re: Disney BRDF material

Posted: Fri Jun 07, 2019 4:41 pm
by Sharlybg
Good news:
My test scene renders faster indeed with all materials on Disney shader and PathOCL GPU!
That is really nice ! and like the dif will be more visible in complexe scene ;)

Re: Disney BRDF material

Posted: Fri Jun 07, 2019 4:43 pm
by Sharlybg
The current situation is: if you want a pre-made build that is easily installed, you have to wait for the next alpha/beta release.
If you want the bleeding edge, you have to read the first three posts here: viewtopic.php?f=9&t=736#p7617 and in general do a few more clicks and stay up to date with recent development (e.g. the opening of the 2.79 branch).

What I would find cool would be an Azure script that creates a new BlendLuxCore daily build whenever:
a) a LuxCore daily build is published
b) a commit is pushed to the BlendLuxCore repo
But it would be a bit of work + requires knowledge of Azure scripts (which I don't have at the moment).
Thanks you for remind me this link. if it is that complicated please it is not worth it forget that :mrgreen:

Re: Disney BRDF material

Posted: Fri Jun 07, 2019 4:48 pm
by epilectrolytics
Sharlybg wrote: Fri Jun 07, 2019 4:41 pm That is really nice ! and like the dif will be more visible in complexe scene ;)
It is really amazing how the LuxCore Devs create a speed boost every two weeks or so.
Who would have thought that Disney is faster on GPU??
While on CPU BiDir in my first test it was slower!