# Face vertex exceeds mesh vertex count

Hello,
I am using Grasshopper for my master’s thesis in construction engineering at the University of Florence. I have had some difficulties in generating the mesh starting from a series of points. In particular, the error “face vertex exceeds mesh vertex count” occurs, when in reality the number of vertices does not exceed the number of vertices of the mesh. Below, I am attaching the screenshot of the problem. Thank you so much for your kind attention,

best regards
Liuba Gabelli

Ciao Liuba

I’m not a Grasshopper user, just guessing …

Maybe what exceeds the vertex count is a vertex index ?

Always post the definition (or part of it by isolating the issue). Diagnosis based on an image is rather impossible (and a bit annoying).

Other than that and given the opportunity: a Mesh Vertex is a Point3f on a per Face basis, while a Mesh TopologyVertex is a Point3f on a per Mesh basis (this may “contain” many vertices [valence etc]). Meaning that IF you construct the Mesh, say, face by face AND unless you use the CombineIdentical Method … you may have far more vertices than you imagine. All that mean that the TopoVertices indexing differs to the Vertices indexing (but there’s Methods from/to assuming a valid and manifold Mesh). Note that the Vertex Normals use the Vertices indexing. Finally If you play with V/E/F connectivity (3*3 = 9 possible combos) I would strongly suggest to use TopoVertices.