Editing Revit setup for OpenBIM/Revit IFC import pitfalls

When you need to author an IFC file which will be opened by Revit things get complicated as they are for export (see: [[Revit setup]]). This page list some pitfalls to avoid.

=Mandatory conditions=
Having an <code>IfcBuildingStorey</code> is optional in IFC standards but mandatory for Revit (Last test: revit-ifc 21.1). Else an empty file will be created. Building elements like walls will be missing. <ref name=link group="workarounds">Link the IFC file instead of importing it. Some elements behaviour might change eg. a wall geometry become not modifiable by hand</ref>

In IFC standards an <code>IfcProduct</code> can be contained in an <code>IfcSite</code>, <code>IfcBuilding</code>, <code>IfcBuildingStorey</code> or <code>IfcSpace</code> <ref>''[https://standards.buildingsmart.org/IFC/RELEASE/IFC4/ADD2/HTML/schema/ifcproductextension/lexical/ifcrelcontainedinspatialstructure.htm IfcRelContainedInSpatialStructure]'', IFC documentation</ref>. However if you do so, Revit will link element to a newly created <code>Level</code> called ''Default'' on import. <ref name=link group="workarounds"/>

=Geolocation / Model far from origin=
Revit will not import your model correctly if your geometry is too far from Revits internal origin. Although in any software it is not a good idea to have large coordinates. Use relative placement as much as possible.

You might be able to see the model by linking the IFC instead of importing it.

=Workarounds=
<references group="workarounds" />

=References=
<references />

[[Category:Autodesk Revit]] [[Category:Proprietary software]] [[Category:Industry_Foundation_Classes_(IFC)]]
@@ Line 1: / Line 1: @@
-{{Autodesk_Revit}}
+When you need to author an IFC file which will be opened by Revit things get complicated as they are for export (see: [[Revit setup]]). This page list some pitfalls to avoid.
-{{IFC_Documentation}}
-If you intend an IFC file to be opened/imported with Revit things get complicated, just as they are for export from Revit (see: [[Revit setup]]). This page list some pitfalls to avoid.
 =Mandatory conditions=
@@ Line 9: / Line 7: @@
 =Geolocation / Model far from origin=
-Revit has currently no option to choose which base point an IFC model should be positioned by, it will be placed at the internal origin. If the IFC model is placed to far from this origin, Revit will not import your model correctly. Although in any software it is not a good idea to have large coordinates. Use relative placement as much as possible.
+Revit will not import your model correctly if your geometry is too far from Revits internal origin. Although in any software it is not a good idea to have large coordinates. Use relative placement as much as possible.
-You might be able to see the model by linking the IFC instead of importing it, but if the coordinates are large (world-coordinates) the IFC needs to be pathced before it kan be linked in to Revit. This can be done in BlenderBIM:
+You might be able to see the model by linking the IFC instead of importing it.
-* Go to the scene pane and look for "IFC Patch"
-* Choose either "ResetAbsoluteCoordinates" or "OffsetObjectPlacements" in the Recipie dropdown.
-* Choose filepaths to patch and patched
-* If you choose "OffsetObjectPlacement" add in the "arguments"-field the Shared Coordinates in Revit in opposite direcion seperated by comma. <code>x, y, z, rotation</code> E.g: <code>-128900, -1532260, 0, -19.5</code>
-=IfcSpace=
-When linking <code>IfcSpace</code> are converted into Generic Model and it is not possible to fix this. See issue [https://github.com/Autodesk/revit-ifc/issues/15 revit-ifc/issues/15]. A [https://github.com/Autodesk/revit-ifc/issues/15#issuecomment-558748917 workaround] is to create a model with spaces only and import it instead.
 =Workarounds=
@@ Line 26: / Line 17: @@
 <references />
-[[Category:Autodesk Revit]] [[Category:Proprietary software]] [[Category:Industry_Foundation_Classes_(IFC)]] [[Category:IFC invalid practices]]
+[[Category:Autodesk Revit]] [[Category:Proprietary software]] [[Category:Industry_Foundation_Classes_(IFC)]]