hi,

Can someone explain what returned indices from GetTopologicalVertices Method refer to? I get some indices but they are not corresponding to the mesh vertices index.

I thought that obj_ref.Mesh().Faces[faceNumber] and obj_ref.Mesh().Faces.GetTopologicalVertices(faceNumber) were supposed to return the same indices result.

thx

Hi Raf

they refer to the â€ślogicalâ€ť amount of vertices of a mesh. Meshes can have more vertices for two reasons: some vertices can be unused, and some vertex-points can be repeated so that different normals can be assigned to the (for example, along the sharp edge of a cube). TopologicalVertices gives a single index for each of these. You can then trace back to which â€śnormalâ€ť mesh vertices the topological vertex refers. Please also note that TopologicalEdges refer to these indices, rather than the other Vertices.

To compute this information, once a mesh is constructed and until itâ€™s edited, Rhino caches topological information regarding vertices.

I hope this is helpful

## Giulio

Giulio Piacentino

for Robert McNeel & Associates

giulio@mcneel.com

Hi Giulio, Ok it sounds clear now. Thank you for you explanation.

Raf