I’m going to use the IFC Type IfcDistributionChamnberElement as an example.
The Archicad Classification 2.0 system has an identical Classification to map the AC to the IFC classification types.
The IFC Type Product - IfcDistributionChamnberElementType - has a drop-down list of Predefined types and any one of our projects, it’s certain that we will want to assign one of these Predefined types to elements in the building model.
What do I need to do in the “Map IFC types for Export” dialog so as to enable a selection from a drop down list when editing a specific instance of the object. As the two images suggest, I'm not seeing the option selected in the Map dialog when I open the Edit element dialog.
Posting a response I got in another forum from Nando Mogollon:
Hi Aaron, In short, there's nothing you can do to make that "greyed-out" field to be a drop-down list. The predefined type can be changed but in a different way. Indeed intuition dictates that the option should be available from the Element's Properties panel. My understanding is that it is not selectable ( as drop-down list or else) from there is because its type selection is driven By the Archicad Classification System. So, to get the Predefined Type (ifcDistributionChamberElementTypeEnum) to read the desired type in the Properties and therefore in the exported IFC, you will need to classify it (Archicad Classifications) with one of the sub types (Manhole, Trench, InspectionPit or whatever). Then the Preview Translator will make the Element to display the correct match in the Predefined Type (in the Properties tab/window)
A couple of notes: The current Archicad Classification system is a direct match ( not 100% but close) to the IFC4 list of entities and predefined types. Note that if using IFC2x3, predefined types are set to Userdefined /Object Type, not predefined types In the case of requiring other sub types (not pre defined but User defined, then just create a new Archicad Class for it, and map it to the Translator/Map IFC Types...
I have to be honest with you and say that I build my own Classification System as a 1 - 1 match of all of the IFC4 ProductType options. This way I can set up my translators for a 1-1 import and export also. The current Archicad Classification System by not covering everything means you need to add to it to make it meet your needs. Hence why I went with a different approach of creating mine from scratch.
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