Hi all,
First of all like to acknowledge that, Revit plugin is a great tool for BIM modellers and have become an integrated part of design. Though I work more in Archicad rather than Revit, I was disheartened of not being able to use the Revit plugin. After trying IFC import export between these two manually , finally I am happy to say that I get clean Revit IFC model with zones that had been created in Archicad environment by using there Archicad Revit IFC converter plugin.
I used the Revit Pollination plugin to extract the HB zone model and it worked perfecly extracting windows, doors and zones. Now its possible for archicad IFC model to be used indirectly for HB zone model extraction.
What is happening is that the room in the middle (Meeting) is recognizing the wall the left and the door inside of it as one of the objects that bound this room. However, for some odd reason the room on the left (Ladies) is not recognizing that same wall as a bounding wall and so it doesn’t include the door. Validation error comes from the fact that in theory that’s impossible. If you have a wall with a door in it, then rooms on each side of the wall would recognize that same wall as its bounding object, and would both have that door in it with a Surface condition. That’s not what we are seeing here. Why?
I can only speculate but that model as you said is an IFC import. IFC is notoriously bad as a reliable format for exporting/importing geometry out of Revit. Even in this model it did bunch of weird things. There are a bunch of Room Separation Lines created in the middle of the walls? Who knows why, but that will interfere with our ability to recognize walls as bounding surfaces and extract doors/apertures. It also creates these weird wall conditions where seemingly single wall gets broken down into smaller segments where each one is off the plane by a few mm. Example:
OK, but that’s not helping you. How do we fix this issue? I just deleted the extra Room Separation Lines to begin with. Then I deleted that wall between Ladies and Meeting rooms, and drew it again. That was it. I guess that caused Revit to refresh its geometry calculations for rooms, and now both rooms recognize that wall in the middle as a bounding object, both rooms get that door included, and now when its boundary condition gets set to Surface, it’s a valid Surface condition.
It still complains about some energy property, but that’s probably because of all of these weird double walls that IFC dropped all over the place.
My recommendation would be not to rely on IFC imports. Revit has a history of being really bad with IFC export/import. It creates a really “dirty” model.
Thanks for the detailed info @ksobon. That was quite helpful. So I guess for now I still need to wait for any development for an archicad pollination plugin to get clean analytical model.
@asisnath I think it’s safe to assume that an IFC import into Revit that needs some cleanup is better than nothing. I am just trying to stress the point that IFC imports into Revit will not be “clean”. You will need to do some work to get a nice model out of them. By no means am I trying to discourage you from using Revit.
The error message is because the interior wall has a non-symmetrical External Wall construction assigned to it. That should not technically happen but is easy to fix in the Rhino plugin.
That’s unlikely to happen anytime soon unless someone from the ArchiCAD team develops a solution for generating HBJSON files from their models. We don’t have the expertise in-house for dealing with ArchiCAD. At least not now.
