Mutable Destroys Metahuman Face (Advanced Rig logic for Mutable)

[Mantikator]

I know that the Mutable plugins are in beta/experimental state, but because of their huge potential we are trying to implement it to our metahuman customization workflow.

However, we ran into a fundamental issue that we are unable to fix when swapping metahuman heads in a customizable object instance during runtime. After compiling the CO in editor, everything seems to work, unless the editor is being restarted twice, or the project is running as a packaged build. Then the face bone structure is breaking exactly as described in the Mutable wiki, as if there were no advanced rig logic plugin (or the wrong DNA) in use.

I attached a very small repro project and images of what my basic setup looks like.
We would be very thankful if anyone could let us know if there is a mistake in my graph, or if it is a bug and if there is any fix or workaround for us.

We use Unreal 5.5.3 (latest launcher version). The metahumans are up to date, just downloaded from Bridge.

Repro: MutableMetahuman.zip - Google Drive

Just hit play in the startup map. Head swaps when pressing V on the keyboard. You can tell that it’s broken for example when the white character’s nose has a dent (like in the image).

Best regards,

Matthias

[M4ttr1xST (Pep Sánchez)]

If you dig in GitHub code updates you’ll find a couple of submits that corrects this. Although this is not backwards compatible and it’s difficult to backport to 5.5.3, so it will require to upgrade your project to latest version in Github.These are the commits that solve this issue:

[Mutable] Convert ModelResources to UObject. https://github.com/EpicGames/UnrealEngine/commit/ea8756dabb5a48244d58d308d7a6a198acc71ea0
[Mutable] Re-enable DDC for cook and turn off Asynch cook. https://github.com/EpicGames/UnrealEngine/commit/1ce9c86280880940b7ec303eada38af968e6ef4d

Hope this helps!
Best

[ddibb1 (ddibb)]

Isn’t 5.5.3 the latest version?

Edit: Nvm, realized now that this was for 5.6…