IfcExport IfcProjectedCRS IfcMapConversion

[nathan_torggler]

Hi there, 

I tried to understand how Revit exports the geographic reference to ifc.

I figured out that EPSG Code, Description, Geodetic Datum, Easting, Northings, Elevation and Angle from True North is exported quite easy.

I couldn't find any option to define:

- IfcProjectedCRS.VerticalDatum

- IfcProjectedCRS.MapProjection

- IfcProjectedCRS.MapZone

- IfcProjectedCRS.MapUnit

- IfcMapConversion.SourceCRS 

- IfcMapConversion.TargetCRS

- IfcMapConversion.XAxisAbscissa

- IfcMapConversion.XAxisOrdinate

- IfcMapConversion.Scale

Is there by chance an option included in Revit to define these options?

Also I find i really akward, that the IfcMapConversion by 8 Attribute inheritance, but Revit exports 10?

And the the ifcdirection is exported as 6.1230317691118863E-17 also if the Orientation is 0.?

Actually also the Northings is exported as 106900.xxx-xxxxxxxx; I just removed the rest so it is more clear.

In Archicad it seems quite straight-forward.

[ridantuo]

Hello.

I think you should check these out so you get a better understanding how it works in Revit:

https://github.com/Autodesk/revit-ifc/issues/255

https://gopherproxy.meulie.net/thinkmoult.com/1/ifc-coordinate-reference-systems-and-revit

[nathan_torggler]

Not helping to my topic. @ridantuo : please read carefully.

[ridantuo]

Guess I am not understanding what you want then.