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Mantaflow fluid simulation - Particles for Spray, Foam and Bubbles are one frame ahead of Mesh
Closed, ResolvedPublic

Description

System Information
Operating system: Win 10
Graphics card: GTX 680

Blender Version
Broken: 2.82
Worked: (optional)

Short description of error

The Spray, Foam and Bubble Particles seem to be one frame ahead of the Fluid Mesh.

Spray should be outside of the Mesh
Foam should be on the surface of the Mesh
Bubbles should be inside of the Mesh

After renaming the cache files for the mesh to shift it one frame everything looks way better then with the original mesh
lMesh_0001.bobj.gz -> lMesh_0000.bobj.gz
lMesh_0002.bobj.gz -> lMesh_0001.bobj.gz
lMesh_0003.bobj.gz -> lMesh_0002.bobj.gz
.
.
.

check attached .jpg

Exact steps for others to reproduce the error
open .blend file
bake fluid (Water Domain)
bake fluid (Water Domain.001)
bake Mesh (Water Domain)
bake Mesh (Water Domain.001)
bake Particles (Water Domain)
bake Particles (Water Domain.001)
rename cache files for one Mesh (Water Domain.001) (lMesh_0001.bobj.gz -> lMesh_0000.bobj.gz .....)

Event Timeline

Richard Antalik (ISS) changed the task status from Needs Triage to Confirmed.Feb 19 2020, 3:37 PM
Sebastián Barschkis (sebbas) triaged this task as High priority.Mar 20 2020, 1:14 PM

@Michael Goles (GoleM) Hope this fixes the issue. Since this is a very important fix for 2.83, please reopen if you find things that are still not as expected. Thanks!

@Michael Goles (GoleM) Hope this fixes the issue. Since this is a very important fix for 2.83, please reopen if you find things that are still not as expected. Thanks!

I was trying to find out if the issue is fixed, but the build I downloaded last week crashed when trying to bake particles. The build I downloaded today doesn't crash, but after baking there are no particles generated in the simulation. The official Blender release generates particles, so there doesn't seem to be anything wrong with the simulation per se.

@Gordon Brinkmann (tk1214) Interesting, can you attach the file which does not generate particles?

@Gordon Brinkmann (tk1214) Interesting, can you attach the file which does not generate particles?

Well never mind, it generates particles now. I had a file from 2.82 already with baked data and baked mesh (which worked in 2.83) and tried to bake particles, but they didn't show up. After freeing all bakes and baking it completely new in 2.83 (which I tried to avoid) the particles were there. But the particle bake is much slower than in 2.82 (the data and mesh are baking in more or less equal time).

Still the particles seem to be one frame ahead of the mesh and there are bubbles outside of the mesh. And like in 2.82, when I want to render an animation with 150 frames, I have to bake 151 and set the end of the animation to 151, or else frame 150 would render without any particles (although they show up in the viewport). But that's a different issue. All in all I think I'll stick with 2.82 so far since mantaflow appears to be still buggy.