Hi,
I’m sure there are better ways. Looking forward to see a solution nicer solution.
But here’s what I came up with.
I used the Py-ParametricTools from Maxon Labs: https://labs.maxon.net/?p=3158
These will be needed for this scene to work:
test_multiple_extrudes.c4d (177.1 KB)
You will see a bunch of consecutively executed Inner Extrudes and Extrudes on a hemisphere (which is still parametric). The thing is, one needs a selection to start with.
- So I made a copy of the hemisphere, made it editable and created a selection. This selection has to match the parametric object. If the number of subdivisions were changed, you’d need to create a new selection.
- Not strictly necessary, I copied the selection to the parametric hemisphere.
- Add the Py-Extrude and Py-InnerExtrude Deformers and restrict them to above selection. Done.

Of course this relies heavily on the inner workings of C4D’s modeling tools (the inner extrusion in this case), as these simply append new polygons. After each step, the selection still points to the original faces, which happen to be the “center” ones of the inner extrusion.
Not ideal, but maybe it can at least save you a few steps, if nobody else comes up with a good solution.
Cheers