On the Solids tab of the Modify DWG/DXF Export Setup dialog (see Exporting to DWG or DXF), you specify one of the following options to determine how solid geometry in 3D views will be exported.
- Polymesh. Exports all visible Revit geometry as polymeshes. A polymesh is a 3D shape consisting of multiple polygons that are meshed (joined) together. For example, a polymesh cube consists of 6 square surfaces that are joined together to form the cube shape. This geometry is referred to as face-based.
- ACIS solids. ACIS is a solid modeling technology. For example, ACIS represents a cube as a single object or shape with 6 sides. Any elements that are already polymeshes (such as toposurfaces and import symbols that contain polymeshes) remain as polymeshes.
- AutoCAD® Architecture and AutoCAD® MEP objects. This option is available only when the key ExportACAObjects is added to the Revit.ini file and its value is set to 1. When the option is selected, you can select the type of objects from the Prefer drop-down list.
