If the box is made of NULL material, it may not work. Just use the world volume and remove the NULL material boxepilectrolytics wrote: ↑Mon Sep 23, 2019 7:11 pmThere is a fog box around the room, the camera and emitters are outside and no world volume defined.
When I define one and assign it as exterior to the fog box and the emitters, there is no change in rendering, still no incoming beam and the caustic beams are too bright.
(I think @FarbigeWelt has somewhere tested BiDir against Hybrid with lasers and volumes and found similar inconsistencies.)
Spheres scene challenge
Re: Spheres scene challenge
Re: Spheres scene challenge
A side note from observing this scene.
With a simple test, to again show not to expect too much out of PT vs BiDir... no matter how many tricks or time one invests, IME, lack of precision and feature richness is constantly limiting the creation of effortless beauty.
"Laser on. A matte plane in a Fog."
Compute Unit: CPU
Halt Time: 30s
PT
BiDir
Also, from a quick look into details it seems to me there are quite a few differences between old Classic and New Core without any change to the scene IDK, just looks like too much time went into circling around the hot potato...
With a simple test, to again show not to expect too much out of PT vs BiDir... no matter how many tricks or time one invests, IME, lack of precision and feature richness is constantly limiting the creation of effortless beauty.
"Laser on. A matte plane in a Fog."
Compute Unit: CPU
Halt Time: 30s
PT
BiDir
Also, from a quick look into details it seems to me there are quite a few differences between old Classic and New Core without any change to the scene IDK, just looks like too much time went into circling around the hot potato...
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Re: Spheres scene challenge
Yep, that worked (for the incoming beam).
With world volume, PathOCL Metro + PGI and light tracing I could trace the rays completely.
Still volume caustics per light tracing are too bright and reflections on glass bodies are also missing
(Simple glass without dispersion for testing).
Re: Spheres scene challenge
Could you share that scene please.epilectrolytics wrote: ↑Tue Sep 24, 2019 7:38 amYep, that worked (for the incoming beam).
With world volume, PathOCL Metro + PGI and light tracing I could trace the rays completely.
Still volume caustics per light tracing are too bright and reflections on glass bodies are also missing
(Simple glass without dispersion for testing).
Screenshot.jpg
Full Hybrid Back/Forward path tracing - I don't like clamping - Bidir it's great but very slow - I have 4096 MiB de Vram and I want to cry.
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Re: Spheres scene challenge
I didn't save that one, but was able to recreate it for v2.3beta on Blender 2.81a.
The "incoming beam" directly from the IES light is not rendered by light tracing (because no caustic before going through the first sphere) and therefore extremely slow to converge.
I did never finish this render but it will need several thousand samples.
Best to use PathOCL with Sobol sampling (better than Metropolis as I just discovered).
The engines have been changed in the mean time but volumetric caustics from light tracing are still too bright IMHO.
The "incoming beam" directly from the IES light is not rendered by light tracing (because no caustic before going through the first sphere) and therefore extremely slow to converge.
I did never finish this render but it will need several thousand samples.
Best to use PathOCL with Sobol sampling (better than Metropolis as I just discovered).
The engines have been changed in the mean time but volumetric caustics from light tracing are still too bright IMHO.
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Re: Spheres scene challenge
Wow Thank you very much for taking the time to reconfigure the scene.epilectrolytics wrote: ↑Sun Feb 09, 2020 10:18 am I didn't save that one, but was able to recreate it for v2.3beta on Blender 2.81a.
The "incoming beam" directly from the IES light is not rendered by light tracing (because no caustic before going through the first sphere) and therefore extremely slow to converge.
I did never finish this render but it will need several thousand samples.
Best to use PathOCL with Sobol sampling (better than Metropolis as I just discovered).
The engines have been changed in the mean time but volumetric caustics from light tracing are still too bright IMHO.
Although I have a doubt, why is the mirror material mixed with metal?
Full Hybrid Back/Forward path tracing - I don't like clamping - Bidir it's great but very slow - I have 4096 MiB de Vram and I want to cry.
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Re: Spheres scene challenge
Full Hybrid Back/Forward path tracing - I don't like clamping - Bidir it's great but very slow - I have 4096 MiB de Vram and I want to cry.
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Re: Spheres scene challenge
Yep, while light tracing is faster than BiDir, path tracing (of the volumetric scattering from the IES light) is way slower than BiDir so that it makes no sense to render it this way.
I wonder why adaptive sampling (with Sobol) is not catching this.
I think there is already an implementation for user defined sampling (brush? area?) in LuxCoreUI but not yet in Blender which would definitely help with this scene.
I wonder why adaptive sampling (with Sobol) is not catching this.
I think there is already an implementation for user defined sampling (brush? area?) in LuxCoreUI but not yet in Blender which would definitely help with this scene.
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Re: Spheres scene challenge
It just dawned on me that the problem with the incoming light could be easily solved by putting a glass pane in front of the emitting plane, outside of the screen.
Then it will be a caustic beam like the rest and rendered quickly with light tracing