Somebody knows how the IFC export options in Revit work?
File > Import/Export Settings > IFC Options > Export Options gives you a simple list of categories. For each category you can determine to which IFC Class Name it will be exported. Seems very obvious to me...
I used the exportlayers-ifc-IAI.txt for exporting. When I change the catergory Grids from Not exported to IfcGrid or IfcGridAxis I won't get an IFC file with grids. The default settings are that Rooms are not exported. Whatever I tried the exported IFC file contains an IfcSpace. I also put all the categories to 'Not exported' but I will the same file (??!!!).
I played around with the settings but to me it seems that these options are useless. I would like to export my Revit model to a customised IFC file. For example I'm only interested in exchanging the walls, columns and floors.