Sequential Extrude With Partial Recombination Creates Seemingly Non-Conforming Mesh
Hi everyone,
I'm extruding a hybrid 2D mesh consisting of a block of quads surrounded by triangles. To create a 3D mesh, I'd like to extrude the quads in the block and recombine them afterwards into hex elements using a prescribed no. of layers. Outside the block, I'd like to create a (mostly) tet mesh using the same no. of layers. Hence, at the boundary of the two, I should get some pyramids connecting the hex and tet mesh in order to keep a conforming mesh.
However, gmsh does not seem to change the outer tet mesh when recombining the elements inside the block. There are no pyramids in the mesh and the outer region seems to contain additional edges on the block/air boundary that are not part of the block volume.
I've added a MWE and two pictures, one showing the hex elements inside the block and the other one showing the tet elements at the air/block boundary. I'm using the latest stable Gmsh 4.9.4. on Windows (but happy to check w/ other versions or OS).
Many thanks for your help!
Erik