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

Rui Maciel rui.maciel at gmail.com
Wed Feb 24 22:22:52 CET 2010

Geordie McBain wrote:
> Yes, I see what you mean.  The ASCII representations are a little
> ambiguous.  For the tet and hex I had thought the u-axis was behind
> and to the right of the vw-plane, while for the prism the u- and
> v-axes were forward and for the pyramid the u-axis was forward with
> the vw-plane in the plane of the page.  With those interpretations,
> all four systems are right-handed, but I think there are other valid
> interpretations; e.g. for the prism the u- and v-axes could be into
> the page which would give a left-handed system.
> Perhaps the figures would be clearer if where one edge crossed
> another, the closer edge symbol was used, rather than using a
> plus-symbol?

You are absolutely right.  The ASCII art drawings have a M. C. Escher's 
Waterfall-ish touch to it. I failed to see it the right way the first time 
around but once you see it you just know it's there.  And it's perfectly 

Thanks for the help, Geordie.  Kudos!

Rui Maciel