topic Re: Questions about IFC_predefinedtype GDL parameters ? in Archicad C++ API

Questions about IFC_predefinedtype GDL parameters ?

Nader Belal — Thu, 06 Oct 2022 11:20:59 GMT

Hi there,

As many of you may know IFC_predefinedtype is an Archicad predefined integer parameter to communicate the library part with the Archicad's IFC add-on.

Does any of you have an insight for the values' definition of IFC_predefinedtype in your API documentation? Because I have checked the GDL references in PDF and online and there is nothing.

Re: Questions about IFC_predefinedtype GDL parameters ?

Akos Somorjai — Mon, 10 Feb 2020 09:59:50 GMT

Hi,

This is more of a question for the https://gdl.graphisoft.com forums.

Sorry, Akos

Re: Questions about IFC_predefinedtype GDL parameters ?

Nader Belal — Mon, 10 Feb 2020 10:41:52 GMT

Thank you Akos

Re: Questions about IFC_predefinedtype GDL parameters ?

Nader Belal — Sun, 01 Mar 2020 16:03:18 GMT

Hi there,

I'm putting the answer to this question, based on @Akos Somorjai recomendation.

Péter Baksa wrote:

I got some clarification from the developers:

An IFC translator has a "Type Mapping" preset, where a classification-based or element-based rule set can be defined. In the template shipped with AC, the classification system "ARCHICAD Classification" is set up to work with the IFC translators, always defining an IFC type and Predefined Type. Using these translators, IFC_predefinedtype has no effect.

When an IFC translator is set up to use element mapping, the mapping is not customizable by the user, and depends on the AC version. For AC23 this document shows two MEP element types where IFC_predefinedtype is handled by the translator. On the AC side, these parameters are handled by the MEP add-on.

So IFC_predefinedtype is retired, it exists in GDL elements only for compatibility.

source: http://gdl.graphisoft.com/forums/topic/questions-about-ifc_predefinedtype-gdl-parameters/#post-18588