DXF/DWG files exported from Concepts & ViaCAD contain encyrpted SAT data, per AutoDesk specification for surfaces and solids. The embedded SAT data provides exceptional compatability for complex surfaces and solids. (Concepts/ViaCAD and AutoCAD are based on ACIS and can share data precisely using SAT).

However, not all applications understand or support the embedded SAT data in DXF/DWG files. (Plus AutoDesk encrypts it) To get around this, export your data as R12. R13 was the first AutoCAD version to be based on ACIS. By exporting to R12, all surface and solid modeling data will be converted to facetted data supported by most applications.

Increase your display resolution to obtain finer facetting prior to exporting. If that still does not give enough resolution, use the Edit:Change Object type to Mesh and specify desired facetting.