Dear ZoranB,
Unfortunately, there is no direct solution to convert a body to a face in AutoCAD. But you can use one of the following solutions:
1- Save the drawing including the body in IGS format and open the saved IGS file.
2- You can use Mechanical Desktop (the command AM2SF).
I need to model some curved surfaces in SAP2000 (FEM).
Since it is impossible to create complex surfaces in SAP, i guess i should use dxf import option. Elements in dxf file should be face objects in order to be recognized by SAP.
I've drawen solid objects and generated body object using "copy face" option.
I cannot use acad surfaces, because it is impossible (i think) to get intersection line of two face objects.
Any other idea?