Reference Point COGO

Developers
1

Hello everyone,

We are looking for IFC equivalent of “Reference Point” or “COGO”.
• Position for PIs;
• Limits of a parcel;
• Position of Light Pole;
• Vertical Signal;
• Representative Trees;
• Manhole position; or…
• Simply reference coordinate;
• Etc.
•

With IFC we have IFCGeographicalElement but we are not sure it would fit for all cases.
Moreover there is no specific entities to describe coordinates (Lat/Long and UTM).

Is there any work in progress on that topic?

Thank you in advance.

2

For a reference coordinate (e.g. in UTM), you should have look at entities IfcMapConversion and IfcProjectedCRS (versions IFC4 and up). The rest can be placed relatively to that reference point (like trees, border points, etc.) using IfcObjectPlacement and its derivatives. See Figure 7 here for a schematic.

There is a good paper on different possibilities on georeferencing IFC model data here. I agree with authors’ assertion that only LoGeoRef 50 is the only option with enough data for precise localization.