Vertex groups disappear after Append from 3.0 to 2.83?

Support Animation and Rigging
1

Hello,
I rigged a basic character while just parenting the non complex parts and rigging with automatic weights and empty groups (for manual weight paint) the complex ones (legs & arms).

Now when i Append the animated character to a previous version of Blender (2.83) the arms and legs are not parented to anything and their vertex groups disappeared.

The Append from 3.0.0 to another 3.0.0 scene work well but i need him in 2.83. Is that a new bug to report ?

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2

3.0 recently changed where vertex groups live : in mesh rather than object. I would think this is related, but to make sure I’ll take the liberty to ping @HooglyBoogly if you don’t mind

Cheers,

Hadrien

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3

Opening in a previous version isn’t considered a bug. See:
https://developer.blender.org/T90746

I am not certain about the appending case though. You can export using a format that saves vertex groups, and reimport as a workaround.

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4

Not a bug, you’re talking about backwards compatibility, which we already know isn’t there from 2.9+ backwards. IIRC there’s even a warning if you open a new file in 2.83

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5

Thanks all for your answers
I should have inquired about that before tried a project in 3.0.
So now have I a way to get back my vertex in a lower version ? Or is it recreating the rig the only solution?
I tried exporting it in fbx, dae, collada, gltf… there’s always one part of the export that is screwed

6

You can make a list of all vertex weights, their names… and read it back from 2.8

7

I don’t get it. Does it mean i have to do this for each vertex separatly ?

8

No of course not, I meant from Python

I haven’t done this before, but it’s definitely possible and shouldn’t be very difficult. I don’t have time to work on it for you unfortunately. Here is the API doc : https://docs.blender.org/api/current/index.html#

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9

Thanks you !

10

I came across this problem and found an unexpected solution just now, so I thought I’d post it here. I have hundreds of blender models, animated and not, stored in Unity Project libraries, so I really needed to solve this problem without having to go through all my files and doctor each file individually.

I closed my other software down (Unity Game Engine) and uninstalled and reinstalled the latest Blender. And all my vertex group data was restored, even on my back-up drives. I don’t know why this worked for me, all I know is that it did work.

Hope it helps some one else.

Peace