I made an assembly that I converted to Part. I made some changes and then converted that Part to IGS. Following the import of the IGS into SW, one of the bodies turned into a surface instead of a volumetric.
How do you put it back in volume?
I tried the "sewn surface" function but I only have one surface element so the function cannot be used....
First of all, have you made an import diagnosis? Right-click on one of the volume or surface functions of your "Import Diagnostics" part. It solves a lot of small rebuild bugs.
This function is only accessible if you have not added new functions in the Feature Manager of this part from an IGES (no material removal, ...).
Did you check that there is no discontinuity in your surface before trying to sew it? Solidworks is very good at getting straight ends to walk around where it shouldn't be
For the record, it is an AutoCAD model, converted into a STEP, registered as a Part, modified and then registered as an IGS, to finally be taken back as a Part :)! Aaaah the hazards of multi-media modeling for 3D printing....