Fixing/removing BoundaryMesh is in my sights for when MeshView is implemented (https://bitbucket.org/fenics-project/dolfin/issue/329). There are problems with BoundaryMesh (particularly in parallel) that have been causing headaches.
Garth On 21 January 2015 at 07:55, Martin Sandve Alnæs <[email protected]> wrote: > Hi Matthew, > a BoundaryMesh is 'just a mesh' and FEniCS does not > preserve cell orientation, instead the vertex list in each > cell is sorted by global vertex number. This gives implicit > agreement of the edge direction between cells. > > Martin > > On 20 January 2015 at 18:17, Matthew Scroggs <[email protected] > > wrote: > >> Dear all, >> >> I have been attempting to implement FEM BEM coupling with Fenics and >> BEM++ and have encountered the following issue: >> >> When importing a mesh into Fenics then exporting the Boundary mesh, the >> normal vectors for each element are a mixture of inward pointing and >> outward pointing. (Before importing, they were all outward pointing). >> >> The following code is where the issue occurs: >> >> import dolfin >> from bempp.grid import grid_from_element_data >> from bempp.file_interfaces import export >> >> mesh = dolfin.Mesh('sphere.xml') >> bm = dolfin.BoundaryMesh(mesh, "exterior", False) >> bm_coords = bm.coordinates() >> bm_cells = bm.cells() >> bm_nodes = bm.entity_map(0).array().astype(np.int64) >> bd_grid = grid_from_element_data(bm_coords.transpose(),bm_cells. >> transpose()) >> export(bd_grid,'grid.msh') >> >> >> I have attached the imported and exported meshes. >> >> Matthew >> -- >> Matthew Scroggs >> PhD Student >> Department of Mathematics >> University College London >> >> _______________________________________________ >> fenics mailing list >> [email protected] >> http://fenicsproject.org/mailman/listinfo/fenics >> >> > > _______________________________________________ > fenics mailing list > [email protected] > http://fenicsproject.org/mailman/listinfo/fenics > >
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