Mesh

This part works with UsdGeom, UsdMesh, e.t.c.

Get mesh from prim

mesh = UsdGeom.Mesh(prim)

Get face and point information

vertex_points = mesh.GetPointsAttr().Get()
vertex_counts = mesh.GetFaceVertexCountsAttr().Get()
vertex_indices = mesh.GetFaceVertexIndicesAttr().Get()