Caustics quality

[Micha_cg]

Caustics quality

Vlado, thank you for your test and the suggestions.

I have here a AMD 3800X2 machine and I see two render buckets only, is it right? I think, it should be four buckets. Can you help please?

[Thomas An._cg]

Caustics quality

The caustics photon map settings were 30,000 caustics subdivs for each light; in the render settings: search distance: 0.2; max photons: 0; max. density: 0.04. I'm not sure if the scene scale is the same between the different versions of the file though.

The resulting photon map was huge, a little less than 3GB, but this was not a problem since I rendered the scene on a 64-bit machine with 4 GB of RAM under WinXP 64-bit edition. Even though I used a 32-bit version of V-Ray, the 64-bit version of Windows can give a lot more memory to an application than the 32-bit version.

Also, I should note that the machine was a dual dual-core AMD Opteron at 1800 MHz, so that means 4 rendering threads. If I had to render on a single-processor machine, it would have been about 21h of rendering.

Other than that, the primary GI engine was irradiance map, and the secondary - light cache with 1000 subdivs. "Use light cache for glossy rays" was off. AA was adaptive QMC 1/100, and the noise threshold was very very low - maybe about 0.0004.

Also, while testing the scene, I found a bug in the photon mapped caustics - they were darker than they should be, so I had to fix this first.

Anyways, it's a very difficult scene (precise caustics in V-Ray in general are hard to deal with); although V-Ray did a fairly good job in the end, I think it should be possible to make it better and faster with less memory... just need to figure out how

Best regards,
Vlado

Vlado,

Awesome
Thank You for sharing the settings.

I had tried a 25000 photon map on my machine (1gb ram) and then played with Max density to limit the size of the map .... but I run into an unexplained problem that vrayFroRhino would abort. I didn't have time to troubleshoot and pin down the issue and so didn't file a report on that yet.

I think it should be possible to make it better and faster with less memory

Yes, we need some magic dust from Vlado
If it would be possible in the future to configure Vray and render this scene on a single proc and bring down the time to less than 5h at this quality ... it would blow my socks off !

-Thomas