In the attached, find 2 curves and a “ring” surface created by revolving a line and then splitting with the two curves. The surface was made with revolve for future texture mapping purposes.
First, Extrude the surface solid 5mm with SplitAtTangents=No (also for future texture mapping purposes). The extrusion takes a few seconds, but it hangs on “creating meshes” (jagged and faster). Esc can’t cancel the meshing. I let it run for 5 minutes, after that I decided to kill it…
Next, re-open the file and try the same thing just extruding the curves as sides (not solid), also with SplitAtTangents=No. That is pretty much instantaneous. Copy the surface upwards 5mm and then select the 4 surfaces and try join. Join will take quite a long time in this case, but if you’re patient it will appear to complete… The command line will blank out for awhile, then the meshing begins… and runs and runs… This one you can escape out of, though - but it eventually does complete after many minutes.
OK, now re-open the file once more, and extrude the surface with SplitAtTangents=Yes. The extrusion itself now hangs for a very long time… Kill it again… Extruding the 2 edge curves (not solid) with SplitAtTangents=Yes also hangs up.
The only thing that actually seems to work correctly is: Explode the two edge curves into 2560 individual segments, then select them all and Extrude solid… Takes less than one second here… Unfortunately, this will leave planar surfaces for the top/bottom and I don’t want that in this case…
Certainly this is perhaps difficult as the edge curves are relatively complex, but still, it seems that there is a problem here somewhere… Since extruding the 2560 individual curve segments works just fine…
–Mitch
ExtrudeJoinMeshProblem.zip (2.0 MB)