RealDWG and Object Enablers
An object enabler is a program that is required to interpret custom objects in a DWG file. If the object enabler is missing, some information in the DWG file might not display correctly. Prior to V8i SELECTseries 1, MicroStation supported object enablers that were rewritten with the Open Design Alliance OpenDWG library, however, there were many object enablers that did not support OpenDWG. As of V8i SELECTseries 1, MicroStation can directly run object enablers that also run on AutoCAD, so the graphical objects created by these enablers are displayed desirably.
When you open a DWG file containing a custom object, and if the enabler is missing, an Alert window appears. The window lists all the missing enablers, some of which may have detailed information such as the provider of the enabler and the website from which you may find and download the needed enablers. Note that an enabler is not required to open a DWG file. When an enabler is missing, the file still opens and its custom objects become proxy objects.
Object enablers that are written to conform to the guidelines published by Autodesk can also be used in programs that incorporate the RealDWG libraries. This is advantageous because when you have the object enabler for an entity, you no longer have to ask the person who provided the DWG file to save it with "proxies" enabled. MicroStation can instead use the object enabler to obtain the graphics representation of the custom entity.
Custom objects created by Autodesk’s AEC products such as AutoCAD Architecture, MEP, Structural Detailing, Civil 3D and others are displayed in MicroStation with the object enablers either delivered with RealDWG or downloaded and installed by the user. However, if you try to open files that contain AEC objects created in an older version, you get an Alert window that provides the options to upgrade AEC objects, open the file as read-only, or cancel the file open process. You can also control this behavior by setting the configuration variable MS_OPENDWGAEC. Following are the valid values for this configuration variable:
- Value = 1 - The file is opened for editing and the AEC objects are upgraded to the current version.
- Value = 2 - The file is opened as read-only.
- Value = null - If not set at all or set to any other value, the Alert window opens.
If you select to upgrade the AEC objects, a message appears in the Message Center saying that the DWG file was last saved in an earlier version of an AEC product; saving this DWG file will update the AEC objects to a newer version, which is incompatible with the version of the software that was originally used to create them. If you edit the file and save it, the AEC objects will be upgraded to the most recent version of AEC object enablers.
Other Advantages of Using RealDWG
There are a number of advantages that result from using the RealDWG technology:
- Improved DWG fidelity.
- When opened in AutoCAD, DWG files saved in MicroStation V8i SELECTseries 1 and later editions will no longer show the alert box that says "This DWG file was saved by an application that was not developed or licensed by Autodesk…"
- AutoCAD's standard SHX fonts are now readily available so you do not have to request them from the provider of the DWG.
Supported Object Enablers
Other object enablers can be downloaded from their respective vendors and installed. You should check the respective vendor's website to get updated products. This includes AutoPlant object enabler; check the Download Center page on Bentley's website for the AutoPlant object enabler availability in near future.
Even if you have previously installed the object enabler to work with AutoCAD, you must go through the object enabler's installation process after you have installed MicroStation, so that it can be found and used by MicroStation.
Object enablers from Autodesk can be either for 32-bit operating system or for 64-bit operating system. Make sure you download and install a correct version of an object enablers on MicroStation.