Computer-aided design software is used by design professionals to design and document real-world objects. Organizations involved in engineering, architecture, surveying, and construction industries use CAD to depict various planning, construction details, and as-built representations of real world assets.AutoCAD and MicroStation are two widely used general-purpose types of CAD software. The data from these softwares are supported by ArcGIS Pro.
CAD datasets can vary in size, scale, and level of detail; they can represent information about the inside of a building at a project scale, or a survey plat at a regional scale. CAD files often depict proposed infrastructure assets, or other proposed changes to the build or natural environment that can be represented on a map in their geographic context. The CAD drawings are often a source of new infrastructure assets, or changes to the natural environment and can be used to create or update GIS datasets. ArcGIS Pro reads CAD files as GIS-formatted datasets to add them to maps and scenes and to migrate into GIS datasets. CAD files can be used directly in many geoprocessing tools and automated workflows for analysis and data creation.
CAD data positioning
CAD data is a common source of GIS content, but before it can be used in ArcGIS Pro, the data must have a defined coordinate location. CAD files are required to have a valid Esri coordinate system (PRJ file), and may require an optional coordinate transformation information (WLD) file to identify how the coordinates in the CAD data should be positioned on the earth's surface.
Notifications appear when you attempt to add CAD data that does not have a proper spatial reference. These notifications guide you to choose a proper spatial reference, and present actions to accomplish necessary CAD data repositioning. To validate the geospatial positioning information for any CAD or BIM file, you can view the Validate Position option of the File Properties dialog box invoked from the right-click context menu of CAD files in the Catalog pane.
Autodesk AutoCAD DWG and DXF
The DWG format is the native file format of Autodesk's AutoCAD software. In addition to Autodesk's AutoCAD, several other CAD vendors also use versions of the DWG file format. ArcGIS Pro reads .dwg and .dxf files that may also contain feature class data created in Esri's ArcGIS for AutoCAD plug-in or Autodesk's AutoCAD Civil 3D software.
The DXF format is an interchange format originally developed for enabling interoperability with other software applications. Its use is declining as software applications increasingly support the DWG format directly with licensed read/write technology from Autodesk or from third-party providers such as the Open Design Alliance.
ArcGIS Pro supports enhanced content in an AutoCAD .dwg file. ArcGIS for AutoCAD and Civil 3D both create additional feature class content in a .dwg file that is useful in ArcGIS Pro.
Bentley MicroStation DGN
The DGN format is the native file format of Bentley's MicroStation CAD software. A unique feature of the DGN format is that you can save it with nonstandard file extensions. This can be used to denote content; for example, you can save a DGN format file with a .par extension to identify drawings containing parcel information.
CAD feature dataset
In ArcGIS Pro, an AutoCAD or MicroStation file is read as an ArcGIS feature dataset of feature classes. This feature dataset contains a spatial reference and a collection of read-only ArcGIS feature classes. The read-only feature dataset and the included feature classes can be added to a map or scene or used in geoprocessing workflows in the same way as any other ArcGIS dataset without conversion.
CAD dataset feature classes
When you connect to a CAD file in ArcGIS Pro, the CAD entities in the drawing are organized on the fly into virtual feature classes that resemble a geodatabase schema.
By default, the CAD entities in the CAD file are organized by geometric type into feature classes. These default feature classes include Point, Polyline, Polygon, Annotation, and Multipatch. CAD entities contain various numeric and text properties that identify their symbology, as well as various parametric and user-defined descriptive attributes. These entity properties are read as feature attributes when the data is interpreted by ArcGIS Pro as GIS features.
AutoCAD .dwg and .dxf files may include additional information from AutoCAD Civil 3D that is included as CAD feature dataset feature classes. These feature classes are derived from the AEC objects stored in the .dwg and .dxf files and are used by the Autodesk Civil 3D software.
AutoCAD .dwg and .dxf files may also include additional information from ArcGIS for AutoCAD or AutoCAD DWG files exported from the Export To CAD geoprocessing tool. This information is included as additional CAD dataset feature class content. These feature classes are encoded using the mapping specification for CAD (MSC) data organization principles used by Esri to store ArcGIS feature classes in an AutoCAD .dwg or .dxf file. These MSC feature classes also contain additional metadata such as an Esri coordinate system definition.
Attributes from CAD entity properties
GIS feature attributes are generated from the CAD entity properties. ArcGIS Pro uses the CAD graphic properties and a number of user-defined attribute sources to generate a virtual table of GIS attributes. Some attribute fields are included from user-defined entity content generated by the CAD author. These attribute sources include AutoCAD block attributes, attributes of MicroStation shared cells, and user-defined attributes from Civil 3D. Predefined field names have been established for the standard properties of CAD fields. Some user-defined attributes may contain field names that are invalid in ArcGIS Pro and are modified to be acceptable. For example, field names that begin with a number are automatically prefixed with the letter t.
Feature classes derived from AutoCAD Civil 3D entities have parametric and user-defined attributes and are included as feature attributes. ArcGIS Pro supports Civil 3D user-defined property sets as feature attributes. The Civil 3D property set name will be included as a prefix to the field name for each included property set attribute.
Feature classes generated using the ArcGIS for AutoCAD plug-in or the Export To CAD geoprocessing tool will include user-defined GIS feature attributes that are included when the CAD data is accessed by ArcGIS Pro.