Do photon based caustics work with DR?

[simmsimaging]

I'm having problems using caustics and DR together - getting what looks like dropped buckets - different colours/brightness happening etc. I am not using a saved map - it is making a new one each time. Can you not use these together or is it something else I'm doing wrong?

Thanks
b

[vlado]

It should be working fine, as far as I know.

Best regards,
Vlado

[simmsimaging]

Okay thanks, I will keep trying to figure it out but so far no joy. Had to render on a single machine to get it done on time.

b

[simmsimaging]

I think the problem I was having is still there, but may not be a DR thing - that may just be coincidental.

Have a look at the two attached images: they are both crops of the VrayCaustic element from a bottle render. The one shows the bottom of the bottle and is the area I was actually concerned with and set the caustics for, but the other shows the upper part of the bottle and the problem is evident there. I cranked up the exposure to show it more, but you can see how chunky/blotchy that part is. It almost looks like caustics are not working with the smoothing on the bottle or something.

I have seen this on other images and in some cases it looks more like buckets getting hit differently. Any idea what can cause this so I can smooth out the whole image properly?

Thanks,
b

[vlado]

This doesn't look like bucket artifacts to me - more like too low caustics settings. What are they now?

Best regards,
Vlado

[simmsimaging]

This one looks less like buckets for sure, but the other image I rendered really did look like a DR problem, but only happened with caustics on. Unfortunately I scrapped the file.

The current settings are:
Only one light creating caustics, it's a vray light about 1cmX1cm
Scene units are cm, and the target object is about 20cm high by about 7cm in diameter.

Light: Caustics subdivisions: 3000

Caustics
(gi caustics are both enabled)

Multiplier 1
Search Dist: 1
Max Photons: 0
Max Density: .25

I am trying to follow some guidelines you gave me in another post. Shouldn't this be okay?

b

[simmsimaging]

Hey Vlado -
I went back and re-rendered a part of that file where the problem looked more like buckets dropped. See attached - it's the VrayCaustic pass, and the RGB pass. The settings are slightly different in that file, but basically the same sort of setup. I rendered this file exactly as is, but without DR and it worked okay. I will re-test that to be sure as well.

b

EDIT: I can confirm this problem only happens with caustics and DR on - although the chunkiness in the first post seemed to happen either way. I guess it is two different issues?