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Spheres scene challenge

Posted: Thu Sep 19, 2019 10:55 am
by sarmath
Kudos to anyone who can setup this scene with LuxcoreRender.
This is the reference image rendered in old LuxRender.
light-transport-simulation-global-illumination-algorithms.png
And here you have link to the scene:
http://www.cg.tuwien.ac.at/~zsolnai/lux ... Spheres.7z
Scene contains textures and laser .ies file for the light.
Good luck.

Re: Spheres scene challenge

Posted: Thu Sep 19, 2019 2:13 pm
by Dade
sarmath wrote:
Thu Sep 19, 2019 10:55 am
laser .ies file for the light.
LuxCore has true laser light source, use that.

Re: Spheres scene challenge

Posted: Fri Sep 20, 2019 8:52 am
by typhoonofdvina
Hello,
I had the same goal, struggled, but succeeded finally thanks to guidance by B.Y.O.B.
I'm attaching related stack exchange post instead just the scene itself, as I think, it is useful to know the pitfalls, I had to overcome.
The scene doesn't reconstruct exactly your image, but uses all those effect around volumetric caustics.
Hope that helps.

Btw, renders shown in that post are only drafts, but final result was really superb.

The post with scene: https://blender.stackexchange.com/quest ... i-backdrop.

Re: Spheres scene challenge

Posted: Fri Sep 20, 2019 6:02 pm
by epilectrolytics
spheresLC.jpg
spheres_luxcore.blend.zip
(568.31 KiB) Downloaded 46 times
I don't get sharp prismatic rings :cry:

The original which is different from the reference in the opening point is a great piece of work, who made this?
I opened it on my MacBook where LuxRender is still installed but I forgot how the material system works there, especially volumes.
I had to use mix materials and eyeballing the IOR for the LuxCore version but it's way worse than the original.

And I'm not willing to run both versions on both computers all night long so here's only noisy examples, sorry.
spheresLR.jpg

Re: Spheres scene challenge

Posted: Sat Sep 21, 2019 12:01 pm
by DEBIHOOD
Ok that's what i have
rnd.jpg
a little later I will publish the file, because not everything is completed
Dade wrote:
Thu Sep 19, 2019 2:13 pm
sarmath wrote:
Thu Sep 19, 2019 10:55 am
laser .ies file for the light.
LuxCore has true laser light source, use that.
When I use the area light source and turn on the “laser” checkmark in it, then the caustic becomes strange lines
lines.jpg
laser.jpg

Re: Spheres scene challenge

Posted: Sat Sep 21, 2019 3:04 pm
by sarmath
NIce results. I was playing with the scene as well and my result is also different than reference.
No mix materials. A bit of compositor adjustments for contrast/colour. Also added lightgroups to laser and floodlight for better control.
Bounces changed to 128 for light and eye like in original scene.
Large mutation probability to 25%
Max consecutive rejects 256
Rendered for about 6h
50% denoiser
And the scene file...

Re: Spheres scene challenge

Posted: Sat Sep 21, 2019 4:50 pm
by DEBIHOOD
Less noisy render, I’ll post the scene tomorrow because I don’t have time right now.
Perhaps some caustics have disappeared due to a limited number of ray bounces

Re: Spheres scene challenge

Posted: Sun Sep 22, 2019 8:34 am
by DEBIHOOD
Here is the scene.
I also fixed problems with a limited number of bounces, now everything works fine.
Here is a file for a blender and for opening in luxcore standalone
Luxcore_spheres.7z
(1.91 MiB) Downloaded 55 times

Re: Spheres scene challenge

Posted: Sun Sep 22, 2019 11:34 am
by sarmath
DEBIHOOD wrote:
Sun Sep 22, 2019 8:34 am
Here is the scene.
I also fixed problems with a limited number of bounces, now everything works fine.
Here is a file for a blender and for opening in luxcore standalone
Thanks DEBIHOOD you have been the closest to the reference but setting up scattering color to pure black you have almost lost that nice beams of light. I have changed it to dark grey to make it more visible. Also the result its achived with laser ies light like in original scene and not true laser as suggested by Dade. If someone can do it with true laser feel free to play with the scene. This is the result after correction...I am very satisfied :D

Re: Spheres scene challenge

Posted: Sun Sep 22, 2019 11:41 am
by DEBIHOOD
I used a dark color for scatter because the same color was in the original scene, I don’t know why the dark scatter color is different in Lux and Luxcore