Metaball animation playback crash #62311

New Issue

alon abrany · 2019-03-07T14:42:13+01:00

alon abrany commented

2019-03-07 14:42:13 +01:00

System Information
system-info.txt

2.80 (sub 46), branch: blender2.7, commit date: 2019-03-06 00:18, hash: 18e5540a48, type: Release
build date: 05/03/2019, 17:06
platform: Windows

Short description of error
File Crash on when playing animation or scrubbing from unknown reason

here is the file
CRASH ON PLAYBACK.blend

**System Information** [system-info.txt](https://archive.blender.org/developer/F6779364/system-info.txt) 2.80 (sub 46), branch: blender2.7, commit date: 2019-03-06 00:18, hash: 18e5540a48b6, type: Release build date: 05/03/2019, 17:06 platform: Windows **Short description of error** File Crash on when playing animation or scrubbing from unknown reason here is the file [CRASH ON PLAYBACK.blend](https://archive.blender.org/developer/F6779429/CRASH_ON_PLAYBACK.blend)

alon abrany commented

2019-03-07 14:42:13 +01:00

Added subscriber: @alonabrany

blender-admin commented

2019-03-07 14:42:13 +01:00

#72586 was marked as duplicate of this issue

blender-admin commented

2019-03-07 14:42:13 +01:00

#69578 was marked as duplicate of this issue

blender-admin commented

2019-03-07 14:42:13 +01:00

#71163 was marked as duplicate of this issue

blender-admin commented

2019-03-07 14:42:13 +01:00

#70794 was marked as duplicate of this issue

William Reynish commented

2019-03-07 15:47:40 +01:00

Added subscribers: @fclem, @WilliamReynish

William Reynish commented

2019-03-07 15:47:40 +01:00

Can reproduce.

Seems to crash in mesh_calc_normals_poly_prepare_cb

@fclem Is this in your area?

Can reproduce. Seems to crash in mesh_calc_normals_poly_prepare_cb @fclem Is this in your area?

Sergey Sharybin was assigned by Clément Foucault

2019-03-07 16:19:08 +01:00

Clément Foucault commented

2019-03-07 16:19:08 +01:00

Added subscriber: @Sergey
Removed subscriber: @fclem

Added subscriber: @Sergey Removed subscriber: @fclem

Clément Foucault commented

2019-03-07 16:19:08 +01:00

It's a threading issue crashing in metaball eval code. Running with -t 1 fixes it.

This is the backtrace P928.

Assigning to @sergey.

It's a threading issue crashing in metaball eval code. Running with `-t 1` fixes it. This is the backtrace [P928](https://archive.blender.org/developer/P928.txt). Assigning to @sergey.

Sergey Sharybin commented

2019-03-08 14:13:02 +01:00

The issue is caused by the legacy design of metaball tessellation, which does create lists of duplicated objects for every object in the scene. This is so metaballs will interact with each other when are emitted from particle system.
This is not a thread-safe process, and the old dependency graph was dealing with it quite stupid: update metaballs (and everything what depends on the,) in a single thread. There is a define MBALL_SINGLETHREAD_HACK in scene.c in 2.7 series.
I imagine that the new dependency graph will crash same way in all the blender versions.

Ideally we would need to change metaballs to have an explicit collection which it interacts with, to make things more clear about what is interacting with what.

That is a quite bug project. For until then the solution is to create the list of interaction by dependency graph and use that instead of iterating over the entire scene.

The issue is caused by the legacy design of metaball tessellation, which does create lists of duplicated objects for every object in the scene. This is so metaballs will interact with each other when are emitted from particle system. This is not a thread-safe process, and the old dependency graph was dealing with it quite stupid: update metaballs (and everything what depends on the,) in a single thread. There is a define `MBALL_SINGLETHREAD_HACK` in `scene.c` in 2.7 series. I imagine that the new dependency graph will crash same way in all the blender versions. Ideally we would need to change metaballs to have an explicit collection which it interacts with, to make things more clear about what is interacting with what. That is a quite bug project. For until then the solution is to create the list of interaction by dependency graph and use that instead of iterating over the entire scene.

Brecht Van Lommel changed title from ~~File Crash on when playing animation or scrubbing~~ to Metaball animation playback crash

2019-03-14 19:07:44 +01:00

Sergey Sharybin commented

2019-10-14 11:33:58 +02:00

Added subscribers: @razorozx, @JacquesLucke