Hi Baltasar, Indeed we sub-sampled discrete entities to compute bounding boxes. I just changed this to a "brutal" bounding box computation in the latest dev snapshot: give it a try (If it's really too slow we should consider storing the information.)
Christophe > On 23 Jun 2020, at 18:41, Baltasar Rüchardt <[email protected]> > wrote: > > Dear everyone, > > I hope you are dealing as good as possible with the pandemic. > > I am puzzled because the bounding box that I obtain from a stl geometry > is smaller than the volume defined by the surface. > > The procedure used is as follows: > > 1. Import stl > 2. Use Bounding Box on surface > 3. Create Points by coordinates obtained from Bounding Box > 4. Connect points to make a volume. > > This is done in create_to_small_box.geo [which should have rather be > named create_too_small_box.geo ...]. > > Background: The stl shows the surface of a heart obtained from a mrt > scan. I first shrink / expand it using the Plugin(Transform) and then I > want to translate it (again using the Plugin(Transform).Tz) such that > the tip of the heart is at the same height as the edge of an electrode > (small example in show_application_of_transforms.geo). My approach was > to use the bounding box zmin- value to compare the heights and then > calculate the necessary transformation by calculating tz= zmin_electrode > - zmin_heart . > > Does someone have a suggestion? Or any help? The alternative would be to > move the stl with meshlab such that the heart tip is at heigh zero, then > I could apply the shrinking and transform in gmsh without problems. > > Thank you very much in advance! > > Best regards > > Baltasar Rüchardt > > > Gmshinfo: > > Version : 4.6.0 > License : GNU General Public License > Build OS : MacOSX > Build date : 20200622 > Build host : gmsh.info > Build options : 64Bit ALGLIB Ann Bamg Blas[custom] Blossom Cgns > DIntegration Dlopen DomHex Fltk Gmm Hxt Jpeg[fltk] Kbipack > Lapack[custom] MathEx Med Mesh Metis Mmg3d Mpeg Netgen ONELAB > ONELABMetamodel OpenCASCADE OpenCASCADE-CAF OpenGL OptHom PETSc Parser > Plugins Png[fltk] Post QuadTri Solver TetGen/BR Voro++ Zlib[fltk] > FLTK version : 1.4.0 > PETSc version : 3.9.3 (real arithmtic) > OCC version : 7.4.0 > MED version : 4.0.0 > Packaged by : geuzaine > Web site : https://gmsh.info > Issue tracker : https://gitlab.onelab.info/gmsh/gmsh/issues > <bounding_box_smaller_than_stl.png><create_to_small_box.geo><outer_boundary.stl><show_application_of_transforms.geo>_______________________________________________ > gmsh mailing list > [email protected] > http://onelab.info/mailman/listinfo/gmsh — Prof. Christophe Geuzaine University of Liege, Electrical Engineering and Computer Science http://www.montefiore.ulg.ac.be/~geuzaine _______________________________________________ gmsh mailing list [email protected] http://onelab.info/mailman/listinfo/gmsh
