Check BlandShape Normal

Created November 16, 2020 Last modified November 17, 2020 Add blendshape normal validation page (de8e1d10)

Since Unity 2018, when importing fbx into Unity, the BlendShape normal is automatically recalculated. As a result, there is a possibility that artifacts are produced on the model’s surface.

Validate surface normal using MToon’s debugging options

Drag fbx to the Hierarchy window and select it. In the Inspector, click Select -> Materials -> Extract Materials and choose a folder to save these materials. Next, select all materials and change Shader to VRM/MToon.

To visualize the surface normal, go to Options - Debugging Options - Visualize and select Normal:

debug normal

Select a GameObject containing SkinnedMeshRenderer with BlendShape. Drag the slider while observing surface normals:

debug normal

We can see surface normals around nose tip and mouth are not correct.

Fix BlendShape normal

To fix BlendShape normal, in the fbx’s inspector, click Select -> Model -> Legacy Blend Shape Normals and check the box.

Now confirm whether the BlendShape normal has been fixed:

fixed normal

VRM - humanoid 3d avatar format for VR