Following OSTexo's Vimeo video on creating threads and after finding out about ShrinkTrimmedSrf I get to that point and when I try to use the command nothing seems to happen - the selected /separated solid threads just become deselected and points don't "shrink" - Am I missing something?

MOI (trial) is kinda funky on Mac, so maybe it's a Mac version short coming ?

MOI 3 trial/Mac OSX 10.11

Hi kahuna - it's normal that you will not see any change of appearance after ShrinkTrimmedSrf, unless you are showing surface control points.

The way trimmed NURBS surfaces work is there is an "underlying surface" that then has trim curves on it which mark holes and cut away spots.

It is possible for that "underlying surface" to be quite a bit larger than the current active area. ShrinkTrimmedSrf will shrink down the underlying surface so it is only as big as needed to contain the trim boundaries.

Since you don't normally see the full underlying surface, any changes to it outside of the trim boundaries can also not be visually apparent. But when you turn on surface control points those are shown on the full underlying surface.

- Michael