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Autodesk / revit-ifc

IFC for Revit and Navisworks (2019+)
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PR: Different project north rotations depending on linking in IFC and corresponding .ifc.rvt file #710

Open Moult opened 10 months ago

Moult commented 10 months ago

Problem Description

This is a related issue to #522 .

When an IFC is linked, in the background it generates a correlating .ifc.rvt file. When an IFC is linked via "Link IFC", bug #522 is triggered: that is, the IFC's +Y project north correlate's with Revit's true north in versions 2022 and up.

The problem is the inconsistency between linking the IFC directly and linking the .ifc.rvt. If you link the .ifc.rvt, the opposite (desired) behaviour happens: the IFC's +Y project north correlates with Revit's project north. The problem is that sometimes users link in the IFC directly and sometimes they share the .ifc.rvt and link that artefact in instead (this saves on having 5 subcontractors having to wait an entire afternoon to load in an IFC ... instead only one person links the IFC, then they share the .ifc.rvt). So depending on which method you use you get different results.

Note that linking in the .ifc.rvt is actually the desired behaviour, firstly because it gets the project north correct, and secondly because it actually gives you options of mapping things like PBP -> PBP (in contrast, linking IFC is stuck on internal origin, see #320 ).

Now we have this strange workflow where we say step 1) link the IFC, 2) remove the link, 3) link the .ifc.rvt using PBP as the origin and only then it'll come in correctly.

Revit Version

2023.1.x

IFC for Revit Addon Version

24.x.x

Windows Version

11 22H2

Teun1 commented 9 months ago

To provide some more insight into what (some) people do with the software, an additional response. I can confirm that linking .ifc.rvt is also what I am doing. The 0 point is understandable, but in my case not the main reason. 1 Reason is that I still don't fully trust a reload from when using IFC. The second reason is to clean up the file before loading it. When adding very detailed IFC files to my Revit project (for example from Tekla) I run a script that does a few things. It removes all IfcAssemblies (these give me duplicate geometry). It removes all objects smaller than 1 inch. Some objects (e.g. a toiletpan) get an extra comment so they can be filtered out more consistently in my own project. The last reason for using .ifc.rvt is that sometimes I have to use Phases. For example, to get temporary items out of the way.