[Gmsh] Local referential for the hexahedron and prism element family

Rui Maciel rui.maciel at gmail.com
Mon Feb 15 13:57:54 CET 2010

Geordie McBain wrote:
> How do you define the sign of a numbering of the vertices in a
> polyhedron?  Is there a definition?

I'm following Gmsh's node ordering reference, which is available at:


> I know for tetrahedra there are two essentially distinct possible
> numbering

This isn't a node ordering problem per se.  My only issue is that according to 
Gmsh's manual it appears there is an inconsistency regarding the local 
coordinate system for the prism family of elements.  In fact it appears that, 
at least on the ASCII art representation presented in the manual, the 
tetrahedron and hexahedron element family follow a "right-hand" coordinate 
system while the prism and pyramid follow a "left-hand" one. 

Either way, this isn't exactly a problem.  I've raised this issue as I'm 
having troubles generating meshes of specific element types and therefore I'm 
not able to check if the local coordinate system inconsistencies are present 
only in the manual's representation or if has any impact on the generated 

Rui Maciel