I’m aware that this topic is old, but I’ve had the same problem and was bashing my head against the wall for solid 4 hours to get it done - so, for anyone googling for the solution for this problem:
While it is true that you can’t “retarget skeletal mesh” as you do with animations, you have another option which was introduced in UE5 (at least I think so) - runtime animation retargeting:
- Create animation blueprint for your custom skeleton having only one node called “Retarget pose from mesh”. In the details panel, select IKRetargeter from Manny to your custom skeleton. Also, make sure that “Use Attached parent” is enabled.
- Inside character blueprint, assign Manny to the mesh and your desired animation blueprint. Also, set “visible” property to “false” and “Visibility based anim tick option” to “Always tick pose and refresh bones”
- Select the mesh, add new child component called “Skeletal mesh”. In the details panel, assign the retargeting animation blueprint that you’ve created in the first step, assign your custom mesh.
It’s done. If youre going to use sockets, it’s best to place them inside the custom skeleton - otherwise the transform might be a little bit off. Other things Foot IK, etc should work out of the box provided that Manny animation blueprint supports it.