Thanks, John. I found that info in tetgen documentation too.

I ran into another problem though. After I incorporated the tetgen sample code from Steffen, my program compiled ok. But at run-time, it stopped at the line:

equation_systems.init();

and gave me the following error:

[0] src/fe/fe_lagrange.C, line 614, compiled Jun 13 2006 at 22:52:46
Aborted

I was wondering if the tetgen conversion from HEX8 to
tetrahedral mesh generated some ElemType that is not recognized by libmesh? How did you guys use tetgen in your code?

Thanks,

David


On 6/28/06, John Peterson <peterson@cfdlab.ae.utexas.edu> wrote:
Quality constraint and area constraint.  Take a look at the
documentation for tetgen if you want to know more.

-John

David Xu writes:
> Hi All,
>
> What are the definitions for X, Y values in
> tetgen.triangulate_conformingDelaunayMesh(X, Y);
>
> Thanks,
>
> David
>
>
> On 6/21/06, Steffen Petersen <steffen.petersen@tu-harburg.de > wrote:
> >
> >
> > Find attached an example file.
> >
> > Steffen
> >
> >
> > David Xu schrieb:
> > > Hi Steffen and John,
> > >
> > > I've been trying to figure out to how to generate tetrahedral mesh in
> > > a simple cubic domain and I just happened to see your emails. I don't
> > > know much about tetgen. Could you guys send me your files so that I
> > > can learn from them?
> > >
> > > Thanks a lot!
> > >
> > > David
> > >
> > > On 6/8/06, Steffen Petersen < steffen.petersen@tu-harburg.de> wrote:
> > >
> > >>
> > >> I cannot see anything suspicious in the code.
> > >> I have just tested a simliar example which worked for me.
> > >> I will send the file to you.
> > >>
> > >> However, I have noticed some other problems.
> > >> In optimized mode I had to change the CXXFLAGS
> > >> in contrib/tetgen/Makefile
> > >>
> > >> #CXXFLAGS += -DTRILIBRARY
> > >> CXXFLAGS := -DNDEBUG -DTRILIBRARY -fPIC
> > >>
> > >> in order to get the example working.
> > >>
> > >> Steffen
> > >>
> > >>
> > >>
> > >> > Hi,
> > >> >
> > >> > I'm trying to use tetgen to generate a tetrahedral
> > >> > mesh in the cube [-1,1]^3.
> > >> >
> > >> > So far, my code is the following:
> > >> >
> > >> >
> > >> > Mesh mesh(3);
> > >> >
> > >> > // add nodes at the eight vertices of the cube
> > >> > ...
> > >> >
> > >> > // Instantiate TetGen interface
> > >> > TetGenMeshInterface tetgen (mesh);
> > >> >
> > >> >
> > >> > // Determine the TRI3 elements which define the convex hull
> > >> > tetgen.pointset_convexhull();
> > >> >
> > >> > // find neighbors, etc
> > >> > mesh.prepare_for_use();
> > >> >
> > >> >
> > >> > // Generate tetrahedra
> > >> > tetgen.triangulate_conformingDelaunayMesh(X, Y);
> > >> >
> > >> >
> > >> >
> > >> > Now, here's where my trouble comes in: for any value of X and Y,
> > >> > I get the following error:
> > >> >
> > >> > tetgen.C:9469: long int tetgenmesh::flip(tetgenmesh::queue*,
> > >> > tetgenmesh::badface**): Assertion `fc != NONCONVEX' failed.
> > >> >
> > >> >
> > >> > What am I doing wrong?
> > >> >
> > >> > Thanks,
> > >> > John
> > >> >
> > >> >