How to Use Model Federation and Geo Referencing in BricsCAD BIM

Quick answer: BricsCAD’s reference point system (Global Origin/Survey Location, Project Location, Site Location) changed with V25. Before then, reference points could only be set by importing an IFC file, stored in the project’s BSYSLIB file and shared across every DWG in the BIM Project. Now, SETSURVEYLOCATION, SETPROJECTLOCATION, and SETSITELOCATION let you add or edit them manually, with coordinates and angle stored directly in the DWG file, so different files can have different reference points.

Adding Reference Points from Scratch

A new drawing’s reference point coordinates and angle default to 0.

Survey Location: set with SETSURVEYLOCATION; toggle its marker’s visibility via GEOMARKERVISIBILITY. It corresponds to the Geographic Location point (found in the Position section of the Geographic Location dialog, confirming the connection covered on this hub’s lights page). Its angle value corresponds to NORTHDIRECTION, the angle between True North and the Y-axis, measured clockwise; changing NORTHDIRECTION only updates the Survey Location angle if a GIS Coordinate System is set in the Geographic Location dialog.

Project Location: set with SETPROJECTLOCATION; toggle visibility via PROJECTLOCATIONVISIBILITY.

Site Location: set with SETSITELOCATION; toggle visibility via SITELOCATIONVISIBILITY.

Both Project Location and Site Location display the drawing’s True North angle, taken from whatever was set via SETSURVEYLOCATION or GEOGRAPHICLOCATION.

Importing Reference Points

1. Open the drawing.
2. Run IMPORT and select the IFC file.
3. In the IFC Import Settings dialog, set the model origin (the IFC file’s reference point) by choosing one of the available options.
4. Click Import.
5. Save the drawing.

Any existing reference point coordinates and rotation angles get overwritten by the information in the imported IFC file.

Exporting Reference Points

If a Site, Project, or Survey Location has been added to a drawing, it’s used when exporting to IFC via EXPORT or IFCEXPORT. Site Location, Project Location, Survey Location, and geographic coordinates can also export to Datasmith (.udatasmith, via EXPORT or DATASMITHEXPORT), confirming exactly the export capability referenced on this hub’s Using TwinMotion page.

Exporting an IFC-based project created in BricsCAD versions older than V25, which stores reference points in the old system, still produces the same results as before; adding reference points with the new commands overwrites that old information during export.

Worth noting: exporting based on the old reference point information isn’t ideal, since not all information from the original IFC import carries over into the project’s BSYSLIB file (angle information for the Site Location, for example). Manually migrating reference points is recommended instead.

Manually Migrating Reference Points

Two ways to migrate reference point information from a BIM Project based on an IFC file saved in a version older than V25:

Re-import the original IFC file into a new drawing:

1. Open a new drawing in the current BricsCAD version.
2. Run IMPORT and select the original IFC file.
3. Save the drawing.

The Global Origin (Survey Location), Project Location, Site Location, and rotation angles derive from the imported IFC file’s information and save into the new DWG.

Manually add the reference points:

1. Open the drawing in the current BricsCAD version.
2. Add the Survey Location, Project Location, and Site Location using SETSURVEYLOCATION, SETPROJECTLOCATION, and SETSITELOCATION, based on the Spatial Locations Manager dialog or the original IFC file you imported.
3. Save the drawing.

Frequently Asked Questions

Can different DWG files in the same BIM Project have different reference points now? Yes, since coordinates and angle store directly in each DWG file, unlike the old system where reference points were shared across every file via the BSYSLIB.

Why isn’t it recommended to export IFC based on old-system reference point information? Not all the original IFC import information carries over into the project’s BSYSLIB file, angle information for the Site Location is one example, so manual migration is preferred.

Does changing NORTHDIRECTION always update the Survey Location’s angle? Only if a GIS Coordinate System is set in the Geographic Location dialog.

Can reference point data be exported to Twinmotion via Datasmith? Yes, Site Location, Project Location, Survey Location, and geographic coordinates all export to Datasmith via EXPORT or DATASMITHEXPORT.