Morph Target shading quality problem


I’m currently working on a character editor in UE4 4.7 and the head mesh on my character has a lot of blendshapes/morph target. Unfortunately I’m facing a quality problem with the shading of the morph targets :


I’m not sure what I can do. Under Maya the Blendshapes work properly. With or without normal map in the material, the result doesn’t change much and stays very identical to the gif above. I’m not sure if it could be a tangent/binormal computation problem over here.

The skeletal mesh was imported with only “import normal” enabled, the rest was computed by the editor.

I’m open to any suggestions.

What does it look like if you let the editor compute the normals on the mesh?

Thanks for your comment. Actually I “solved” the issue (but forgot to reply). It’s related to locked vertex normals in Maya. Locked vertices are imported and kept by the editor. Unlocking them will avoid this problem.