After trying hard to get things to work with vbdfromparticlefluid for the past couple weeks I've had my heart broken with jittery unstable meshes too many times, I've returned to using particlefluidsurface. Not as hip, or sexy, not as customizable, but she gets the job done.

I know others have experienced similar problems, I wonder if VDB at this stage may be more suited to meshing fluid tanks, I'm working with FLIP fluid droplets and splashes.

Haha, I feel you here mate. I've only tried meshing viscous stuff so far and VDB was giving me hell. The tips in the thread below pretty much got things back to the stability of the older surfacer for me.

https://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=37640 [sidefx.com]


All the best

I think it would be helpful if you submitted some sample .hip files into support with the specific particles that you're having a hard time with.

Do you have a hip file you could share?

I tend to use VDB from Particles, as I just didn't quite feel like I had the control/speed I wanted. I'm not sure what it's doing under the hood (it's not a SOP coming from the OpenVDB project, afaik); maybe a developer could talk about what's going on. I wasn't paying attention, and thought it was simply an OTL wrapper (didn't it used to be?), but now it's a C++ node.

Also, there are some OpenVDB slides/notes that have good suggestions and guidelines for meshing fluids: http://www.openvdb.org/documentation/ [openvdb.org]

Thanks Ben, the tips from that thread help a ton. I'll post a hip example as soon I get a moment. The openVDB houdini slides are great resource, thanks

I have never fully got rid of the flicker in slow moving viscous fluids. This is what I have so far in the development.

rob

Hi

It looks more natural meshing than what I've ever seen.
My colleague also has been facing to this flickering problem.

Could you tell us what actually is the fact you've found out?

Thank you.

circusmonkey
I have never fully got rid of the flicker in slow moving viscous fluids. This is what I have so far in the development.

rob

Sorry for the late reply, its been rare of late I actually visit here as I have not been in Houdini land for a while but stuck in Katana hell. Unfortunately as my post is so old it would would take some time for me to acquaint myself with the choc flip again ! .

I do seem to remember I never fully eliminated the high frequency jitters as seen in the spec, even when sucking all the vel out of the particles closest to the surface of the vdb. I was using H13 for the example. Maybe there have been some changes now we are on h15 .

I will be back in Houdini land Jan16 ………….

Rob

there have been huge advances in vdb from h13 (vdb 1.0 i think?) to h15 (vdb 3.0); actually, it's unfortunate h15 didn't pick up 3.1, as it has large speed improvements. cool new stuff in 3.2 that the team is working to release shortly.

definitely check out our slides; I have a diagram which describes how to sculpt a really nice surface. tldr: you need to complement vdbFromParticles with filtering & morphological operations to get the desired result.