Autodesk Architectural Desktop and Bentley AutoPLANT Objects
AutoCAD ObjectARX applications can create custom objects within a DWG file that represent components specific to the application. If the application is present when a DWG file is opened, then the application is used to display the objects. If the application is not present, then a subset of the application referred to as an "object enabler" may be used to display the object. If neither application nor object enabler are present, the object can be displayed using graphic data, or proxy graphics, stored with the object the last time it was displayed.
In editions of Promis.e prior to SELECT Update 8.5.1, object enablers are not supported, and the display in Promis.e matches AutoCAD's display when the associated object enablers are absent. As the storage of proxy graphics is optional (controlled through the system variable PROXYGRAPHICS), some objects may not be displayed at all. In this case, both AutoCAD and Promis.e display only the object’s bounding box.
Effective with SELECT Update 8.5.1, an API is provided to allow development of MDL applications that can enable ObjectARX objects within a DWG file. This API has been used to create enabling applications for Autodesk Architectural Desktop objects and Bentley AutoPLANT objects. These applications are provided with SELECT Update 8.5.1, and objects created with these applications are displayed with complete geometry even when their proxy graphics is not stored in the file.
Bentley AutoPLANT and ProSteel objects in a DWG file that was originally created in AutoCAD cannot be saved in a V7 DGN file.