[Gmsh] high order finite elements

[Axel Gerstenberger]

Dear developers and users,

some time ago I asked for a way to visualize bi-linear elements with 
real bilinear interpolation. The provided solution sent to me can be 
seen in the Gmsh archive under:
http://www.geuz.org/pipermail/gmsh/2006/001816.html

cite:
#############
There is a new functionality in gmsh for displaying high order FEM fields.

add

INTERPOLATION_SCHEME
{
   {.25,-.25,.25,-.25},
   {.25,.25,-.25,-.25},
   {.25,.25,.25,.25},
   {.25,-.25,-.25,.25}}
{ {0,0,0},
   {1,0,0},
   {0,1,0},
   {1,1,0}
};

after the last scalar quad of your map. Then, load your map and go into
the options -> Visibility

Maximum recursion level = 3 and target error = 0.

##################################

It works beautifully, however, I am not able to figure out how to apply 
this to second order elements (say quad9). I guess it must be trivial, 
but somehow I don't see it. Could you give me a hint, please? I think I 
tried hard to find an advice within the documentation, so I hope I did 
not miss it there...

An additional feature would be to show second order triangles and quads 
in one plot, but so far I can only provide one map at the end of the 
post-processing file. Is there a way to show second order triangles and 
quads in one plot?

Thanks in advance for your help and your software.

Best regards,

Axel Gerstenberger



BTW, I read one of the developers recent publications
"Efficient visualization of high-order finite elements"
J.-F. Remacle, N. Chevaugeon, É. Marchandise, Ch. Geuzaine
http://www3.interscience.wiley.com/cgi-bin/abstract/112659093/ABSTRACT

Will these high order visualization techniques be implemented into 
Gmsh2? That would be really a great feature.