Using OCC,I want to create (and ultimately mesh) a 3D spiral with cuts along the outer edge. This works fine when my spiral has two revolutions or less, but when the cutting geometry intersects the spiral a third time, the whole geometry seems to disappear. At least I cannot see it in the webgui. I have made a MWE [1] which hopefully makes the problem clearer. Observe that whether or not the MWE produces the expected result depends entirely on the value of the parameter named ‘revs’.
I can confirm the problem, for recent OCC versions from 7.6 to 7.8.
I believe that the problem is coming from the OCC modeling algorithms.
For debugging, I propose you remodel the geometry using the OCC C++ interface. There are also more parameters available which are not ported to the Netgen-OCC interface.
Here is an example, taking the C++ - modeling of the bottle-example from the OCC pages, and return the final shape to the Netgen-gui.
Most of Netgen-OCC-Python wrapping you can find here:
If the problem remains you may contact the OCC - forum.