The internal origin is the starting point for the internal coordinate system, which provides the basis for positioning all elements in the model.
From the internal coordinate system, you can establish the following:
- The project coordinate system, which provides local context for measuring distances and positioning objects in relation to the model.
- The survey coordinate system, which provides a real-world context for the model.
The internal origin is also called the startup location.
When you create a new model, by default the project base point
and the survey point
are placed at the internal origin. To see them, open the site plan view, or
make them visible in another view.
- To establish the project coordinate system, move the project base point away from the internal origin to another location, such as the corner of a building. If you later want to return the project base point to the internal origin, unclip the project base point, right-click it, and click Move to Startup Location.
- To establish the survey coordinate system, move the survey point away from the internal origin to a known real-world location, such as the intersection of 2 property lines or a geodetic marker. See Define the Survey Point.
Maximum distance from the internal origin
Model geometry must be positioned within 32 kilometers or 20 miles of the internal origin. Exceeding this distance may reduce reliability and result in undesirable graphic behavior. See About the Maximum Distance Limit.
Positioning links and imports by internal origin
When you import or link another model, you can position it by aligning the internal origin of the incoming geometry with the internal origin of the host model. To do this, set the Positioning option to Auto - Origin to Origin or Manual - Origin to Origin.
Spot coordinates by internal origin
When using spot coordinates in the model, you can specify whether the coordinates are relative to the survey point, the project base point, or the internal origin. To report spot coordinates relative to the internal origin, modify the Spot Coordinate type properties, changing the Coordinate Origin parameter to Relative.