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Help transferring facial hair with facial blendshapes

I have a character which had xgen eyebrows and eyelashes. The mesh has about 250 blendshapes for facial animation. I wanted to transfer this to UE4 and I did that by transferring the mesh with blendshapes to UE4. And the xgen hair as alembic. Turns out UE4 doesn't support alembic hair animation (or simulation) if the underlying mesh moves via morphers.

Great, so I had an idea, what if I convert all those xgen hairs to mesh strands and export them all as morphers. I convert the xgen into mesh and used wrap deformer to move them in the scene using the already applied blendshapes. Unfortunately you cannot export this using fbx and I am stuck. 

I could use help this, 
How could I possibly move facial hairs like brows that are attached to a face with blendshapes and not bones, inside of unreal engine? The hairs are not part of the blendshapes.

Replies

  • Obscura
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    Obscura godlike master sticky
    Im pretty sure it does support morph targets cause I tested this explicitly, and nothing special has to be done actually. Which UE version are you using? It should work in 4.25.
  • revoconner
    Obscura said:
    Im pretty sure it does support morph targets cause I tested this explicitly, and nothing special has to be done actually. Which UE version are you using? It should work in 4.25.
    Could you give me a preview of what you did. Not detailed but steps would help. 

    What I did was import mesh as skeletal mesh with morphs. Imported hair as alembic. On the skeletal mesh I added the groom as part of the component and then added niagra below it as groom simulate.

    to test it, I’m using animation blueprint on the mesh in the scene. In the blueprint I’m using set morph target (name of morph), and add the value to 1. On compile the mesh moves but the hair stays at the same place in the scene.

    I am on ue4.25
  • MostHostLA
    The hair system is still experimental/beta However it did work with morphs last I tested it.

    Also, it *has* to work with morphs because it works with any mesh deformation from bones - a skinned mesh.
    Unless you are testing the preview or are on a pre-.25 version you shouldn't be having problems by just binding the groom to the mesh.

    Do a small test with a skinned mesh and 2 bones. When you stretch the bones the groom reacts accordingly when properly bound.
    The morph use a similar process to distort the mesh, thus the groom. Is expected to work all the same.

    There are still engine crashes when binding multiple grooms and a handful of other issues. You should really be using custom hair cards still. Probably into half 2021...
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