Polysurface offset - terrible result vs. Microstation


Modelling some simple tunnel. I modelled inner “tube” as first in Rhino and subsenquently wanted to offset walls. That is when i ran into problems. Seems like seemignly simple task is not that simple for Rhino.

I tried Microstation with imported rhino surface and did it in one click with satisfactory result.

I dont understand how one program can do it easily while other one struggles.

Hi @ivan.galik
I think Microstation uses Siemens’ Parasolid kernel, which is great… and expensive. Rhino uses McNeel’s own, I believe, and it might not be as mature. In this case - without seeing the actual geometry - I would Cap the ends, MergeAllFaces and try Shell instead of OffsetSrf.
HTH, Jakob

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I’ve played around with a similar Brep and had good results with OffsetSrf after I closed the openings.

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shell seems to only work inwards. i need to offset it outwards

yeah it works like that with little postprocessing deleting extra chunks of geometry. thanks