When importing a mesh as skeletal mesh and using any of the MikkTSpace or option to "Import Normals and Tangents" will cause the normals to import incorrectly. If using the Compute Normals or Import Normals option and setting it to "Built in" rather than MikkTSpace the normals will calculate correctly for the skeletal mesh.
Example asset attached, simple box mesh.
Image comparison of Static Mesh vs Skeletal Mesh import of same mesh. Static Mesh on the Left and Skeletal Mesh on the right.
Tested in:
4.11 Preview 1 CL- 2810555
4.11 releases CL-2824708
4.12 - Dev-Rendering CL-2824562
1. Open UE4
2. Import any mesh asset as Skeletal Mesh (box mesh attached to this report)
3. In the import options use any fo the "Normal Import Methods" with MikkTSpace set
Regression: Yes
Results: When using the MikkTSpace Normal Generation Method or Import Normals and Tangents will result in incorrect normals
Expected: Normals should look correct based on the mesh
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