Open a Revit project, and use the Import CAD or Link CAD tools to import or link vector data from other CAD programs, such as AutoCAD (DWG and DXF), MicroStation® (DGN), and Trimble® SketchUp® (SKP and DWG). Revit supports importing most DGN surfaces and solids with the exceptions of cones, B-Spline surfaces, and SmartSolids. For detailed information, see the table below.
|Geometric Elements||Import Symbol||The following DGN elements are translated into an import symbol: line, SmartLine, LineString, multiline, shape, complex chain, complex shape, arc, ellipse, curve, B-spline curve, and pattern. Pattern elements are limited to simple pattern styles.|
|Levels||Levels||DGN levels are mapped automatically into import symbol level. Invalid DGN characters in level names are converted to spaces.|
|Colors||Colors||All colors are translated using RGB values when the Preserve option is selected for Colors.|
|Text Elements, Text Styles||Text Element||TrueType fonts are imported as text elements.|
|Dimensions, Dimension Styles||Dimensions, Dimension Types||The size, spacing, style, and shape of dimensions may vary slightly. Dimension associativity is maintained whenever possible.|
|Fields||Text||Fields are translated as static text.|
|Raster Images||Raster Images||BMP, TIF, PNG, and JPG are the only image file types supported.|
|DGN References||Links||The DGN file type is supported.|
|DGN Design Model||Design Model||The selected design model in a DGN file is converted into an import symbol in Revit.|
|DGN Sheet Model||Sheet||Only models can be imported.|
Suppose that you import an AutoCAD® drawing into Revit and then want to trace over walls in that drawing. As you place the cursor near the lines representing the walls, it can snap to the lines or the midpoint between the lines.
Revit supports reading in proxy graphics from AutoCAD files. Proxy graphics are AutoCAD's representations of AutoCAD Architecture objects. Unlike AutoCAD Architecture objects, proxy graphics have no intelligence.
Proxy graphics can exist for many types of data in AutoCAD, including Mechanical Desktop (MDT) parts and AutoCAD Runtime eXtension (ARX) objects. If you set the Proxygraphics command to 1 in AutoCAD, Revit can then import ARX objects and AutoCAD Architecture objects (such as walls and floors) in the DWG or DXF file.
Revit can import DWG files containing subdivision surfaces and solids created in AutoCAD. Some complex subdivision meshes may fail to convert to a traditional solid or surface altogether, or generate a problematic solid or surface. Other highly complex SubD meshes may not import completely or at all.
An object in Revit must be assigned a category in order for Revit to know how to cut it, whether in plan or section. Geometry in a 3D DWG file imported or linked directly into a Revit project has no category assigned, and therefore will not be cut. For example, if you create a level at the elevation of a typical wall and then switch to a plan view, the imported geometry will not cut at that level. However, if you import the geometry into a cuttable family category (such as Generic Models), the geometry will cut in accordance with Revit’s cut planes.
Import (you cannot use Link) your 3D DWG geometry into the family. You can use any of the cuttable family categories, but most likely the Generic Models category will meet your needs. After you load the family into the project, the imported geometry will cut according to the object styles assigned to the category used.