VDB volume consistency convertion

[Mzigaib]

I am converting my particle sim into a volume VDB (fog) which gives me a very satisfactory result the issue is during the animation the volume doesn't keep the consistency causing a little flickering mostly on the thinner parts, I am using VDB from particles and VDB from fluid and the problem is the same.

Any tips on that?

 

Thanks.

Edited January 29, 2017 by Mzigaib

[Atom]

I have seen fluid sim surfacing flicker if the Influence Scale is low and there is a wide gap between the Droplet Scale. I typically bind the Droplet Scale to the Influence Scale with an expression ch("influenceradius")-0.1. Droplet Scale can never be larger than Influence Scale and the closer the two are, the crisper the surface looks to me.

I created a test scene based on your description and I see no flickering in my resulting output. The particle scale is linked to @age and I have a force separating particles to try to introduce thin spots.

I'm sure your scene is a bit different but without seeing it...

ap_particle_VDB_flicker_issue.hipnc

Edited January 29, 2017 by Atom

[Mzigaib]

Thanks for the feedback!

Yeah it shouldn't be a problem but I am struggling to get a stable result, but in my case I have a sim with lost of particles around 10-15 mil with a certain amount of noise so I have a lot of thin areas where you can see between frames where the issue happens, the thing I didn't mention is that the VDB is been done in real time in a farm and I am seeing some variations between the frames maybe because of that but I know it shouldn't be the case. I'll try what you are suggesting to see the results maybe I also should cache it first.

I've been trying a lot of combinations with VDB smooth, VDB resample and so on I think I got a better result I am waiting the renders to evaluate, anyway thanks for the help I'll keep posted in case I have a breakthrough.

Cheers!