The Mutable plugin merges physical assets only based on the bones specified in the Reference Skeletal Mesh, meaning that any additional bones that appear during the compilation process are ignored. Because of this, there are issues with applying physics using animation blueprints. It is necessary to explicitly set an Override Physics Asset inside Rigidbody node of the animation blueprint so that physics works correctly on bones that are not present in the initial reference skeletal mesh.
However, this approach cannot handle multiple different physical assets within a single Mesh Component. If the physical asset were properly merged even to the bones that appear during mesh generation, it would be possible to use a generic animation blueprint for physics that would work for all meshes with simple physics. That means, it would be possible to combine several meshes, each with its own physical asset, into a single mesh component. For example, a mustache, beard, and hairstyle could all be placed into one “Head” mesh.
Because of all this, I have to separate every element that should have physics into its own mesh component and create a separate instance of the animation blueprint for each skeletal mesh, with an explicitly specified Override Physics Asset.
But here I have another problem, I’m not sure if this is just my own clumsiness, but I often get an error when generating a Customizable Object Instance. As a result, I end up with a completely empty character. This often happens when one of the mesh components is supposed to be entirely empty (for example, when a helmet completely hides a hairstyle and a beard).
My question is: is there a chance that in the future it will be possible to merge physical assets taking into account additional bones that wasn’t presented in the reference skeletal mesh? Or at least a fix or an explanation for the error with generation of the Customizable Object Instance. If necessary, I can provide more information about the generation error.