Autodesk
No way to control the generation of IfcSpaceType
There are two possible scenarios for a user to want:
- Not every occurrence needs a corresponding type. So, don't generate IfcSpaceTypes.
- IfcSpaceTypes have semantic meaning, and so there should be a 1:N relationship between IfcSpaceType and IfcSpace, instead of 1:1 which Revit seems to do.
Hi @Moult, I am looking at this issue now. It's an interesting one that I have a solution for, but want to verify it first. The issue in Revit is that room elements don't have types. They are fairly unique in that sense. As such, when we made sure to export a type for each entity, we just basically exported each room twice, once as IfcSpace, once as IfcSpaceType. This is inefficient.
My proposed solution is to create one IfcSpaceType per predefined type, and that's all it contains. You wouldn't be able to tack on extra information it, but it is artificially created anyway. Does that make sense to you?
It's definitely a step in the right direction, but instead of doing a "oh, for this object, it's a special case" type of solution, have you considered building an IFC data manager as a dedicated feature? That goes for a lot of these types of bugs (managing IfcSystem, managing IfcMaterial, managing rel space boundaries...)
Any sort of short-term compromise would just mitigate but not actually fix anything, and the impression people will get with Revit+IFC is "yeah, Revit can't do that thing".
I remember when I was first building the BlenderBIM Add-on, I would constantly be thinking to myself about how to map a particular IFC feature to Blender's data model. The mappings and tricks just kept on getting diminishing returns until I decided not to fight it anymore and just ... support the IFC data model properly. I'm not saying go all-in native IFC (totally inappropriate, you know more than I do), but "partially native" to plug the gaps where Revit is out of scope is also a valid technical solution?
The company I work for is transitioning from these traditional authoring tools being the be-all and end-all of BIM handover data to being just one "raw input" in a pipeline of data sources that all feeds into a central IFC data model. When seen as part of this larger pipeline, where cost, time, carbon, FM, play much larger roles, it really begs the question about how to deal when Revit has a feature which is "borderline" supported like this one.
Hope I sparked an idea :)
We do have items on our roadmap to continue to improve Revit and IFC integration. This will likely be done piecemeal, but you are right that it is important that IFC feel like a first class citizen and not an afterthought. That said, in this particular case, I am looking for a quick win instead of something that might take a lot longer :)