Please make new bones update blend profiles and masks automatically

This is causing rare visual defects in our project. We have a large team. If someone reimports a skeletal mesh a bone could have been added, possibly not even by them. Or they simply forget to update the existing blend profiles and masks. Now the new bones don’t blend properly during animation transitions.

It has taken a fair bit of time, it takes time to validate these meshes intermittently, time to debug when someone starts pointing out visual defects, its just a headache in general. This should be part of the engine functionality.

In the end we did hook into the import/reimport process to detect new bones and update them, but the engine doesn’t make this friendly at all, the new pipeline tools are awful to use, and custom asset factories generally require using them from the start and take too much work to implement for this purpose.

Steps to Reproduce

  1. Import UE5 Manny fbx file
  2. Create a blend profile or mask and set non-default value on spine_01, e.g. 0.565
  3. Modify the fbx file to add spine_new under spine_01, export it
  4. Reimport UE5 Manny from the fbx we just exported
  5. Check the blend profile or mask that you added, spine_new will have a default weight, and not 0.565

Expected: spine_new is imported with 0.565 to match it’s parent.

Hi, sorry for the delay getting back to you on this. I think this change makes a lot of sense. The dev team are also happy for the default behaviour to be changed to this. I’ll get the modifications made - it seems like it should be trivial, so I’ll aim to get it into 5.6 for you.