Morph Targets and Animation

Hi,

I have been dealing with this for a while now so I decided to ask here. (Sorry for this being so long, I am trying to be as descriptive as possible.)

I am trying to create a simple character customization for my WIP project as seems logical I reached out to Morph targets my workflow is as follows:

  1. Create character in Makehuman (Exported as FBX)
  2. Create several morphs of that character (Each exported as FBX)
  3. In Blender join these targets as shape keys
  4. Import to UE4
  5. Retarget animations

Everything works fine IF I do not change the height of the model using a morph target for height. And by everything works I mean all the animations behave as expected, all non height related morphs do modify the mesh as they should etc…

But once I modify the height morph target this happens:

The body and the hands get significantly deformed.

Please note this is a Mixamo based animation, but happens the same on retargeted Mannequin animations.

Significant things to note:

  • The morph targets look ok when there is no animation playing
  • In Blender if I move the bones while the shape key value is modified there is no deformation happening
  • If I import the animation into Blender the mesh gets deformed as well.

The skeleton bones are

male_t
  Root
    pelvis
      spine_01
        spine_02
          spine_03
            clavicle_l
              upperarm_l
                lowerarm_l
                  hand_l
                    index_01_l
                      index_02_l
                        index_03_l
                    middle_01_l
                      middle_02_l
                        middle_03_l
                    pinky_01_l
                      pinky_02_l
                        pinky_03_l
                    ring_01_l
                      ring_02_l
                        ring_03_l
                    thumb_01_l
                      thumb_02_l
                        thumb_03_l
            clavicle_r
                ...
            neck_01
              head
      thigh_l
        calf_l
          foot_l
            ball_l
      thigh_r
        calf_r
          foot_r
            ball_r

Things I have tried so far:

  • Change the pose from A to T (Easier retargeting from Mixamo)
  • Uploaded T pose character(with Morphs) to Mixamo and let them do their work
  • Uploaded T pose character(without Morphs) to Mixamo and retargeted to morph capable model
  • Changed all settings that came to mind during the import(Smoothing groops, update skeleton pose, use T0 as ref pose and others)
  • Used UE4 4.19-4.21 to try things out

The skeleton I used in Makehuman is GameEngine(tried it with others as well with no change), for the A pose I used a blender script to get the bones to the correct position and adding the twist bones(so it is more or less compatible with UE4 skeleton). This is why I tried the T pose which is just plain T pose with no extra modifications done during the morph target creation process.

I am pretty sure I am missing something obvious somewhere, did anybody run into this and managed to resolve it? Any ideas what to try?

I understand that this is probably the animation issue as it happens both in UE4 and in Blender, I also tried multiple from both Mixamo and the Engine content and all have the same issue.