Hi Marco,

> Is it a convenient techinique to run the "ShrinkTrimmedSrf" and "merge" commands in order to get a cleanup model ?
> (I refer in particular to the "merge" command)

Well, you can if you want to, it probably shouldn't do any harm.

I guess I can think of a case with surface models where you probably wouldn't want to do it, like if you have a planar surface that's a rounded rectangle made up of lines and arcs and it's a standalone surface not joined to anything else. Running merge on that type of surface will merge together all its edges into one single edge since the lines and arcs were smooth where they touched but now you've got one single segment instead of separated lines and arcs, and that means that the lines will be degree elevated and be made up of more points than when they were simple 2 point lines and some of the logical structure of the object is gone.

Personally if you have a structurally sound object I'd generally hesitate to mutate it by automatically doing these things unless there was a lot to gain like if the edges were very badly fragmented or if the active area of a surface is very tiny compared to the full surface.

- Michael