CGAL users discussion list

[Richard Downe <>]

I'm using the AABB_polyhedral_oracle surface meshing demo code to remesh 
a surface -- basically, I combine 2 or more (6 or 7 is the high side of 
what is common) disjoint tubular meshes using NEF_polyhedron.  The .off 
file I get when I write the NEF_polyhedron to a file is clean, with no 
self intersections, and I can view it in tecplot without difficulty.

The problem comes with the remeshing -- I remesh to smooth the surface 
and guarantee that my triangles are as regular as possible, etc., since 
the downstream processing is computational fluid dynamics.  Most 
surfaces work fine.  The attached surface I continually get

File: /usr/include/CGAL/Surface_mesher/Surface_mesher.h
Line: 248
Explanation: (0.0200637 0.0244694 0.0292433) is already inserted on 
surface.

in spite of the fact that the .off file appears to be fine.
If I set  Tag to Non_manifold, it meshes successfully, but the output 
surface contains a patch where some of the facets are reversed.  I feel 
as though this provides some insight into what might be wrong/breaking, 
but I don't know enough to intelligently pursue it further.  Wondered if 
anyone else might have insight.
Attached is the .off file from the NEF_polyhedron pre-remshing.  I can 
supply the final mesh as well, but it is quite large, and sending both 
will put me over the attachments size limit, thus if anyone would like 
to see it, let me know and I'll send it along separately.
Thanks.
--rd

Attachment: cgal.off.bz2
Description: Binary data