Trouble offsetting surface from Grasshopper

I’m having trouble getting clean geometry from this surface I developed in Grasshopper. When I offset it, I am getting messy overlaid surfaces I can’t trim or edit well. I’ve tried breaking it down into a polar section using meshtrim and attempted to clean it up that way with no luck. I even dupbordered it and tried to rebuild a section with sweep2, and trimming with no luck. Any suggestions for how I might be able to get better editable geometry would be greatly appreciated.

here is the file if anyone wants to take a look

Bowls.3dm (12.5 MB)

Hi James - if the offset distance is greater than inside curvature radius, you will get a mess…In this case offsetting inward at 2 which looks like about what you are after, indeed makes self- intersections - that is expected since the radius here is less than 2:


Ah thanks. That makes sense. Any Ideas of how to go about trying to add thickness to this surface and filleting the top edge? I am really stumped. My latest attempt, I trimmed the mesh down to one “section” and cleaned up the mesh to make it clean to polar array and extrude. After I did that I am running into the problem of a messy polysurface that I can’t fillet.

I’m thinking my approach is wrong but I am not sure where I fell down the wrong rabbit hole.

The cleaned up “section”

Messy extruded polysurface I can’t fillet.