Blender occasionally freezes when doing a pose related action in a blend file with pose assets

[Arthur Dent]

Blender 3.3 LTS
Diffeomorphic : 1.6.2.1177
MHX : 1.6.1.0063
Animation Pose Library : 2.0

When doing some pose related action like switching into pose mode or importing a pose or moving the armature in a blend file that stores Pose Assets, blender occasionally freezes and goes into whitescreen mode. It does not crash but remains unresponsive.

I can trigger the issue by moving the hip bone as seen in the image below

I've loaded up blender using the blender_factory_start_up.cmd and ensured that the blend file I was working did not crash when doing any pose related operation.

I then proceeded to turn off every addon until blender had the same enabled addons as the factory settings and slowly turned on the other addons that i normally use until I hit a point where the issue manifests itself

Using this method I traced the issue to the MHX addon because when i disable the MHX addon, (and restart blender) and load up the file and perform the exact same operation, everything works fine.

Unfortunately this issue is reproducible most of the time, but not all of the time. There were a few occasions when I could perform pose related operations without having to disable the MHX addon, but they are few and far in between and now I simply workaround it by disabling the addon and doing what I need to do if blender freezes.

I don't know if the blend file in question is the culprit, or the poses themselves are to blame and is causing MHX to crash, or if the Pose Library addon used by the Asset Manager is responsible somehow but I've also experienced it with other blend files.

The poses themselves were imported from Daz poses using the Import Pose in Diffenomorphic and were marked as Pose Assets in the current file.

I have attached the blend file that I mention above. You need to have the Animation:Pose Library addon enabled to be able to use the poses stored in the current file

I hope that I've given as much information as I can for Thomas (or anyone else out there) to be able to reproduce this as it is driving me nuts.

[Thomas Larsson]

Fixed in latest commit, I think. The culprit seems to be the update function for the property MhaLimitsOn. However, this property doesn’t seem to do anything useful; there is already another property that toggles rotation limits. When the property was removed completely Blender no longer freezes. Note that you need to update mhx_rts, and also import_daz if you want to generate new mhx rigs.

[Thomas Larsson]

No, it still freezes when the mhx plugin is enabled, and now I have run out of ideas. Could be a Blender bug.

[Alessandro Padovani]

daz studio 4.15.0.30, blender 3.3.0, diffeomorphic 1.6.2.1183

Limits are bad for ik since this way the ik targets may not work. To work with ik you need the limits off. Below an example of a pose where the hand can’t keep its ik target because of the limits.

Please disable the limits by default, and place a warning in the tooltip.

‌

Also, if it may help, I don’t experience any freeze with the following mhx settings, that are what I personally use.

steps:

1. import G8M, merge rigs, make all bones posable
2. convert to mhx with the settings below

‌

[Thomas Larsson]

Alessandro, I don’t think ik limits have anything to do with the freezing.

[Arthur Dent]

Thomas/Alessandro,

Thank you for taking the time to look into this.

Before I start testing your latest commits, I wanted to point out that I noticed that the MHX version i just downloaded is giving an error when the “Update MHX” button is pressed.

‌

‌

[Arthur Dent]

Unfortunately, as Thomas mentioned, the issue still persists because I can still reproduce the freeze despite the latest fix to both import_daz and mhx.

[Arthur Dent]

Alessandro,

I will give your suggestion a try soon and will reimport the daz figure and convert the rig to MHX as you suggested using the same blend file with the poses.

At this point I’m ready to try anything :)

[Buddyspencer13]

I can confirm this, it happened to me with Rigify, with versions and imports previous to the fix, i.e. old saved scenes, to this, in effect it freezes completely, when moving keyframes in an animation for example and posing.

It seems that disabling the addon was the solution before this, at least in terms of creating animation poses etc.

But by testing the new version and cleanly importing the characters from the new version, along with the other necessary addon, Thomas seems to have fixed the problem with the latest version.

If you have saved scenes with previous versions, the best thing to do is to disable the 2 addon's, go to your old scene, copy the pose, and apply it to your new character by importing from a clean scene with the latest version, or also (append) from the Blender option and go to the old scene and also, choose your animation actions, and load them into your new scenes, this way you will have a clean scene with the animations and poses, so you can animate correctly.

In my case, old scenes, blends, with pre-Fix imports were unusable for animation, with the addons active of course, except for copying the pose and actions.

Edit : after some longer tests, it seems that the bug persists, even with the latest addon versions.

[Alessandro Padovani]

@Thomas Just to point out that my first comment on limits was not related to the freeze, it was to stress that limits don’t work fine with ik. My second comment on mhx settings was related to the freeze, but if the freeze is for old scenes as @Spencer reports then the mhx settings don’t matter.

@Arthur According to @Spencer the solution is to re-import the figure with the up to date version of the addon. Let us know if this works for you. In general I don’t know if the addon is always granted to be back-compatible. For production it is better to stay with the same version and backup, especially when @Thomas is working on features that you use.

[Arthur Dent]

Alessandro,

I will also try Buddyspencer13’ solution too in the very near future.

All the blender work i do is hobby work and tinkering, and I tend to use alpha versions of blender to get the latest features as early as possible, so compatibility is not an issue for me

Thank you all for taking the time to look at this PITA.

[Alessandro Padovani]

user error