[Gmsh] Ruled surface interpolation
Christophe Geuzaine
cgeuzaine at ulg.ac.be
Wed Apr 30 21:41:47 CEST 2008
Martin Aunskjær wrote:
> Hello,
>
> I've used Gmsh to generate a 3D mesh around a body
> made of lots of ruled surfaces. All the triangular
> faces on these surfaces receive special treatment in
> my fluid dynamics solver, since they must be modified
> from being flat to being curved. This procedure
> involves projecting a lot of Gauss integration points
> inside each surface triangle onto the real, curved
> surface.
>
> I do this by using the InterpolateSurface() routine in
> Geo.cpp. This seems to work fine, except in those
> cases where a ruled surface has holes. Say, the
> definition is like this:
>
> Ruled Surface(177) = {156, 175};
>
> Then any point inside a surface triangle on surface
> 177 will be projected onto a surface defined by the
> generatrices of edge loop 156, the hole is not taken
> into account (holes are skipped in the interpolation
> routine). This way, the projected point will in fact
> not be on surface 177.
>
> My question is, how can I solve this problem?
>
Someone will have to implement e.g. trimmed nurbs interpolation...
(At the moment the native ".geo" language only uses transfinite
interpolation (using 3 or 4 borders) to interpolate curved surfaces. For
more complex case we usually import STEP or similar files.)
> The surface meshing routines seems to be capable of
> correctly inserting points on ruled surfaces with
> holes. Is there some mechanism in the meshing routines
> that I can reuse to project my surface triangle
> integration points correctly onto any surface ?
>
> Thanks,
> Martin
>
>
> Trænger du til at se det store billede? Kelkoo giver dig gode tilbud på LCD TV! Se her http://dk.yahoo.com/r/pat/lcd
>
> _______________________________________________
> gmsh mailing list
> gmsh at geuz.org
> http://www.geuz.org/mailman/listinfo/gmsh
>
>
--
Prof. Christophe Geuzaine
University of Liege, Electrical Engineering and Computer Science
http://www.montefiore.ulg.ac.be/~geuzaine