ACIS objects describe solids or trimmed surfaces. Revit supports the import of ACIS objects contained in DWG, DXF, and SAT files.
For example, you can create ACIS objects using the AutoCAD commands Draw Solids and Draw Region. You can also import SmartSolids™ from MicroStation® into Revit.
To import ACIS objects, use the procedure Import or Link CAD Files.
Revit supports the following types of surfaces when importing ACIS objects:
You can import NURB (non-uniform rational B-splines) surfaces on ACIS objects in DWG or SAT files into mass or generic model families while you are creating the family.
You can then use the Roof by Face and Curtain System by Face tools to create roofs and curtain systems on these imported surfaces.
To use ACIS imports for face-based host tools, import geometry into an in-place family of category Mass or Generic Model. Face-based tools work best on ACIS solids.
For example, if you create walls by face on a cube, the walls join and miter correctly. If you create a curtain system by face on a solid, you can add corner mullions onto the joins between faces of the curtain system. For more information on face-based tools, see Creating Building Elements from Mass Instances.