Computer-aided design (CAD) is a system of hardware and software used by design professionals to design and document real-world objects. AutoCAD and MicroStation are two widely used general-purpose CAD platforms. These systems are designed to accommodate a wide range of applications. Organizations involved in the engineering, architecture, surveying, and construction industries use them to provide a variety of services.
ArcGIS Pro accepts data generated by AutoCAD and MicroStation-based applications. The types of data generated by both systems are described below.
CAD systems generate digital data. CAD data can serve a range of purposes—from a design plan that is printed as a drawing or submitted as a legal document, to a repository for ongoing as-built information. The 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 in a projected grid zone. CAD files are useful as map content and often depict proposed design information that tells a story. The CAD drawings are often a source of new infrastructure or changes to the natural environment and can be used to 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.
ArcGIS Pro support files from ArcGIS for AutoCAD and MicroStation. Each uses file-based vector formats. Both formats support 2D and 3D information.
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 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 GIS 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 Autodesk Civil 3D that is included as CAD feature dataset features 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 principals 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 properties
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 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 . For example, field names that begin with a number are automatically prefixed with the letter t.
Feature classes created from AutoCAD Civil 3D entities have additional parametric and user-defined attributes and are included as feature attributes.
Feature classes generated using the ArcGIS for AutoCAD plug-in or the Export To CAD geoprocessing tool include their own GIS feature attributes.