Geometries Considered as Features
Any time OpenCities Map opens a DGN file it evaluates the contents and defines feature classes for the graphics. The following types of features may be found.
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XFM-DGN features: Those created by the OpenCities Map XFM system. These can be DGN based features created by XFM placement tools or features extracted from a spatial database. The business properties data are stored in the DGN.
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XFM-RDBMS features: Also created by the OpenCities Map XFM system, however the properties have been defined to reside in an external database such as Oracle or Access. The behavior of XFM-DGN and XFM-RDBMS features is the same.
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Inferred Features: Features not explicitly defined as Native XFM features are inferred. There are a number of ways features are inferred.
| Level |
By default, simple elements are defined as features based on their level name. For elements inferred as features using level names, the feature's class name is set to that of the level name. If the feature name contains invalid characters, they are first changed to underscores in the level name. If the level name begins with a number then it is prefixed with "Level_". If level name retrieval by level ID fails, then the feature name is: "Level_" + levelID. This behavior may be turned off by setting the configuration variable MS_GEOXFM_NO_LEVELFEATURES. |
| Cell Names |
Cells are assumed to represent separate feature classes based on their name. For elements inferred as features using cell names, the feature's class name is set to that of the cell name. If the feature name contains invalid characters, they are first changed to underscores in the cell name. If the cell name begins with a number then it is prefixed with "Cell_". For example: "Cell_4Pole". Orphan cells with cell elements on multiple levels have their feature name prefixed with "Cell_" followed by the level ID. For example: "Cell_48" where 48 is the level ID. Orphan cells with all elements on the same level have a feature name of that level name. If the name starts with a number, it will be prefixed with "Level_" . For example: "Pole", "Level_4Pole" This behavior may be turned off by setting the configuration variable MS_GEOXFM_NO_CELLNAMEFEATURES. |
| MicroStation GeoGraphics Features |
If a MicroStation GeoGraphics project was converted to an OpenCities Map project using the Import tool in OpenCities Geospatial Administrator then a number of rules would have been created to help OpenCities Map determine how to recognize those features. Those rules become part of the project and key off of the MSLINK number defining the feature code. |
| Session Features |
The Command Manager may have an entry titled Session Features. These are features that have been recognized by OpenCities Map but are not part of the feature definitions defined by the active XFM project. When session features are created, default placement and edit methods are also created. These can be used to create new session feature instances and, if business properties are present, edit them. |
- Unsupported Features: These are MicroStation element types that are not currently modeled in the XFM environment and includes:
Valid extended element types are: