Considerations when Performing Transformations

Learn about the rules that should be considered when using the Coordinate System Transformation Tool.

All objects in a drawing will transform into the target coordinate system, including all AutoCAD graphics. In most cases, you may see a slight rotation in the drawing as the view center is also transformed as part of the process.

Tip: It is strongly encouraged to review the generated HTML report after transformation as it will identify the status of objects in the drawing.

Survey Points

Survey points are skipped during transformation.

• Update survey points after the transform completes to move them to the new coordinates.
• A settings option copies the survey point into a COGO point for transformation.

External References (XREF)

XREFs inserted at 0,0 are not transformed. They are assumed as models drawings with a coordinate system that matches the current model.

Note: After the transformation, XREFs may be millions of units away from the rest of the model. The proposed workflow is that these models would be transformed separately and then the drawing would be updated.

Data Shortcuts

Data Shortcuts are not transformed. One of the following workflows is recommended:

• Promote shortcuts in the current drawing before the transformation.
• Update the source drawings for the data shortcuts.

Alignments

Alignments are transformed by moving pass-through points (such as start of alignment or fixed tangents). The dimensions in the alignment (arc radius, A value, or spiral length) with not be adjusted. This maintains the design intent of the alignment during transformation.

Note: Alignment stationing can be radically changed when scaling from one coordinate system to another. Station base elements like points of vertical intersection (PVI) and superelevation stations may need to be adjusted.

There is an option to use a location-based event point. When enabled, objects like sample lines at specified locations adjust to maintain their location, though the station value may change.

Labels

Civil 3D labels are skipped but adjust to maintain the relationship with their parent object.

Measurement Systems

Transformation between metric and Imperial units of measurement is not supported.

Point Clouds

Point clouds are not transformed.

Surface Digital Elevation Models (DEM) and Graphic Files

DEMs (non-TIN surfaces), rasters, and images with insert points transform at the insertion point. They will not rotate or adjust due to the transformation.

Rigid Body Objects

Rigid body objects such as bridges from InfraWorks are not transformed. Most other elements will move, scale and rotate to maintain the latitude/longitude of their design points.