Question about VV Query Oriented Mode and Non-Manifold Mesh Support

[will-zzy]

Hello! I noticed that when RXMesh performs a v_v query (vertex as the seed and vertex as the iterator — which, algorithmically, does not require the mesh to be manifold), the implementation assumes the mesh is manifold if oriented iteration is needed.

I would like to ask: Is manifoldness strictly required when using the oriented iterator? Or, alternatively, could non-manifold meshes be supported simply by replacing this part of the code with block_mat_transpose?

[Ahdhn]

The reason we assume manifoldness with oriented VV is that there is no canonical orientation for non-manifold meshes. Orientation can be either clockwise or counterclockwise but for non-manifold meshes it is not possible to establish a consistent orientation. We are also not aware of any application/use case that requires oriented VV on a non-manifold mesh (since non-manifold geometry usually requires special treatment)