Hi Steve and Michael G.,

Great break down Michael on the STEP vs. IGES!

Steve, Alibre does not allow surface manipulation like other so-called solid modellers like SolidWorks. When you import IGES or STEP it will try to stitch the surfaces together as a "solid" or you can turn that off for individual surfaces. Also, Alibre will direct import 3dm files.

What I do is to use MoI 3D to create most of freeform surface stuff, bring it into Alibre as reference geometry. I then us it to extrude to etc., and add things like draft to it in Alibre. Actually adding draft to my part(s) and making 2D drawing layouts is pretty much all I use Alibre for currently. Everything else I have been doing in MoI 3D.

Also Alibre and Pro-E import STEP and IGES to specific tolerances. This can make them show up as surface models instead of solid models. You can change the model tolerances to generate solids from surfaces most of the time, but it can effect the "down-the-road" usage of the model such as with manufacturing software (CAM programs etc.)

Michael T.