衝突したセカンダリ UV テクスチャの座標
This can be used for 3D texture painting or drawing bullet marks.
If the collider is not a mesh collider, Vector2.zero will be returned.
If the mesh contains no secondary uv set, the uv of the primary uv set will be returned.
Note: A textureCoord2 requires the collider to be a MeshCollider.
no example available in C#