Rigid body cache does not bake if a FLIP Fluids domain is in the scene (Blender Bug)

[rlguy]

Blender Version (including hash): Blender 2.80 (e5e885d0ecb9)
FLIP Fluids Version: 9.0.5.2 (Experimental)
Operating System: Windows 10
CPU: Intel Core i7-7700 @ 3.60GHz
GFX: GTX 1070 8GB
RAM: 32GB

It seems that a Blender rigid body simulation cache is unable to to be baked if there is a FLIP Fluids domain in the scene. Blender only bakes a few frames in the cache and then stops. There are no errors in the system console. After removing the domain, the rigid body simulation bakes without problems.

I suspect that this is a bug in Blender 2.80 since this issue does not affect Blender 2.79. I will need to investigate this further and find out what part of the FLIP Fluids addon scripts is preventing the rigid body simulation from baking so that a bug can be reported to Blender.

Until this issue is fixed, a workaround is to disable the FLIP Fluids domain before baking a rigid body simulation.

Attached is a .blend file that reproduces the issue:
issue409.zip

[rlguy]

Update

It looks like this is a bug in Blender. I have reported the issue here: https://developer.blender.org/T60136

Here is a simplified script which reproduces the issue:

import bpy

def frame_change_pre(scene):    
    new_mesh_data = bpy.data.meshes.new("mesh_name")
    bpy.data.meshes.remove(new_mesh_data)
    
bpy.app.handlers.frame_change_pre.append(frame_change_pre)

[rlguy]

Update: The bug has been assigned earlier this week, so hopefully this will be fixed soon!

This bug also affects the cloth simulator.

[rlguy]

The bug reported to the developers has been fixed. I have tested the fix and it looks like baking an rigid body cache alongside a FLIP Fluids simulation is still not possible due to another issue: #403. This issue will cause crashes when trying to bake a rigid body cache.

I have added a note to the developers about this here: https://developer.blender.org/T60094#700781

I will close this issue and add this info to #403