> On 29 Oct 2020, at 17:49, françois fraysse <[email protected]> > wrote: > > Hello GMSH users and developers, > > I generated a simple quadratic tetrahedra based mesh using default settings > with gmsh v4.6.0. After regularizing, minimum jacobian lies between default > target, ScaledMinjac=0.102 so mesh seems valid, no warning or errors. > > Then in a separate code I post-process the mesh and build quadratic shape > functions. I evaluate the determinant of the Jacobian at the 10 nodes of each > tetra and it turns out that I get some small values below zero for some > tetras : ~1e-2/1e-3. > > I do not exclude a mistake in the verification procedure, but I didn't find > it so far. > > My question is : is ScaledMinJac an exact value or an approximation ? >
The value is not exact, but the validity check is a provable bound, i.e. we we report that the element is correct it should be. Can you run the AnalyseMeshQuality plugin and check the results? Christophe > Thank you for developing such a great software :) > _______________________________________________ > gmsh mailing list > [email protected] > http://onelab.info/mailman/listinfo/gmsh — Prof. Christophe Geuzaine University of Liege, Electrical Engineering and Computer Science http://people.montefiore.ulg.ac.be/geuzaine _______________________________________________ gmsh mailing list [email protected] http://onelab.info/mailman/listinfo/gmsh
