> On 14 Jan 2020, at 17:57, triimaran <[email protected]> wrote: > > Hello everyone, > > is there any way to change all selected lines/curves to have the same > direction? > I want to make a structured mesh for a simple room with a rectangular heater > inside and rectangular inlet and outlet on different walls. All geometry > lines I have are either parallel or perpendicular. All I need is to choose > some parallel lines in one view and set the progression so that the mesh will > be finer near a wall. Unfortunately lines from both imported or created > geometries tend to have quite random directions. I know that I can change in > geo file particular lines in Transfinite Curve function by writing minuses > ("-") before chosen curves (e.g. Transfinite Curve {1, -3, -4, 6}), but this > solution is ok just for geometries with not too many lines. It is even more > troublesome and unreasonably time consuming when imported geometries have a > lot (usualy x4) duplicated lines.
Using the API you could iterate over all the curves, check the orientation (using e.g. getDerivative()), and set the meshing constraint based on that. Christophe > And here comes my second, minor problem: > > Coherence function does nothing in this case. When I import STEP file there > is even no way to delete any part of the geometry. When importing IGES the > Delete option works, but lines are also duplicated and to delete them I would > have to delete first all volumes and surfaces, then create them again, which > is also too time consuming for a bit more complex geometries. Although, I > guess, if all chosen lines could have direction changed as mentioned above, > then duplicated lines should not be a problem, because I could use "Coherence > Mesh" at the end of meshing (which seems to work properly). > Edit: when trying it now Delete function does not work also for the .iges > imported geometry. I have no idea what has changed. > > Please find attached geometries (I used only .step and .iges because > exporting to .brep was always filling it with a lot of triangles). These > geometries are just for an example (made in Fusion 360, I was trying hard to > use FreeCAD but failed to use slicing functions to make it possible to > export). In the .geo file I used the Transfinite Curve for one set of lines > to make the problem more clear (mesh 1 and then 2D). > In the attached pictures there is how my final geometries will look like > (made in Gambit - I am trying not to use it further also because of the same > problem: no way to change the lines' directions and after one meshing they > all become random, so to change something I would have to delete everything > and start all over). > > This is my first time writing here so please forgive me in case some of these > problems are obvious to solve. > > Best regards > J. > > <view_gambit2.png> > <view_gambit1.png> > > <example_structured.iges><example_structured.step><example_structured.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
