> trimming works with subsurf also in maya.

Hi Claas - usually this type of trimming is a way to cut polygons into smaller polygon fragments.

This is not the same kind of trimming operation as NURBS-style trimming. In NURBS trimming, the surface itself is not diced into small surface fragments along a trimming boundary, instead the surface stays as it originally was, and new "trim curves" are calculated which live on the surface.

The trim curves can be removed later on to restore the surface.

- Michael