How To: Create CAD files from ArcGIS 9.x feature classes with the EXPORT TO CAD tool
The EXPORT TO CAD geoprocessing tool creates CAD files from ArcGIS feature classes. Following, is a discussion on how to create CAD files from feature classes in ArcGIS 9.x using the EXPORT TO CAD tool. Included, are related articles to address specific functionality.
By default, the EXPORT TO CAD tool takes as input one or more ArcGIS feature classes and creates a CAD file (.DGN, .DXF or .DWG) where the analogous CAD entities are created with the default CAD symbology.
By default, the ArcGIS feature layer name is used to name the CAD layer of exported features, and analogous CAD entities are created from the geometry of the ArcGIS features.
However, it is possible to override or enhance the default behavior and access additional functionality by including specially named CAD fields and a seed file to specifically control the creation and content of the output CAD files.
The EXPORT TO CAD tool includes the following extended functionality:
By including specially named CAD fields in the exported ArcGIS feature layers, it is possible to control the various CAD properties, including the layer name, color, line type, the entity type, and so forth.
An AutoCAD seed file is optional for creating AutoCAD drawings or .DXF files, but may be required to access advanced workflows and extended functionality, such as the creation of AutoCAD block INSERT entities.
A valid Microstation V8 seed file is required when creating Microstation V8 drawings. A Microstation V8 seed file is required to set the appropriate coordinate system definition for the output Microstation files.
A sample seed file for 3D and 2D Microstation drawings is provided in the ArcGIS template directory. However, it is unlikely that the sample files in the template directory will be ideal for personal design files. Therefore, it is required that a personalized, valid Microstation V8 seed file is supplied to get meaningful results.
Click the 'show me' to display the article on how to create a Microstation seed file: <a href='http://support.esri.com/en/knowledgebase/techarticles/detail/27629' target='_blank'>How To: Create a Microstation seed file for use with the Export to CAD geoprocessing tool</a>
AutoCAD or Microstation seed files control the symbology, layers, the definition of blocks and other drawing specific parameters.
Anticipating the CAD layer names from exported feature layer names, with a seed file where layer symbology for those layers is predefined, is an easy way to create a formatted CAD drawing with varied symbology using the default functionality. <a href='http://support.esri.com/en/knowledgebase/techarticles/detail/28331' target='_blank'>How To: Export features to specific CAD layers</a>
Direct individual features from a feature class to different CAD files by including valid path values in a 'DOCPath' field. <a href='http://support.esri.com/en/knowledgebase/techarticles/detail/28333' target='_blank'>How To: Create multiple CAD files from one or more feature classes</a>
Append to any CAD file by supplying an existing drawing as the output CAD file name in conjunction with specifying the proper GP overwrite environment variable and the ALWAYS APPEND parameter of the EXPORT TO CAD tool.
Use a seed file to include a title block or other drawing content in the exported CAD files. This is another way to append to a CAD file.
The GP overwrite environment setting dictates whether or not the file is overwritten or appended to. The ALWAYS APPEND parameter is used to override the GP overwrite environment setting.
By default, CAD entities are generated in the output CAD files from analogous feature types. It is possible to override the default CAD entity type. For example, it is possible to use POINTS to create TEXT entities or create LINES and ARCS instead of LIGHTWIEGHT POLYLINES.
Specifying a CAD entity type ('CADType') of 'INSERT' in conjunction with specifying the block INSERT name in a field called 'RefName', can create block inserts from ArcGIS point features. <a href='http://support.esri.com/en/knowledgebase/techarticles/detail/28330' target='_blank'>How To: Create AutoCAD block inserts with attributes from ArcGIS point features</a>
By default, EXPORT TO CAD creates planer LIGHTWEIGHT POLYLINES in AutoCAD from ArcGIS linear features. To export polylines with 3D vertices, the resulting AutoCAD entities are planer and the elevation is set to the Z' coordinate of the first vertex.
To Create 3D polylines in AutoCAD, include the 'CADType' CAD field and set its value to '3D POLYLINE' to create polylines that have vertices with varying Z' coordinates. <a href='http://support.esri.com/en/knowledgebase/techarticles/detail/28333' target='_blank'>How To: Create multiple CAD files from one or more feature classes</a>
Microstation 3D linear features can contain vertices without using a specific 3D polylines as is required with AutoCAD. Therefore, there is nothing special that needs to be done to create 3D linear Microstation elements from 3D ArcGIS linear features.