Revit to IFC: An Export Guide - Part 10 - IfcPresentationLayer (CAD Layer)

Summary

The video explains how to assign and manage IFC presentation layers (CAD layers) for Revit model geometry. Layers can group elements and control their visibility. In BIMcollab Zoom, an element’s layer appears as a property, and a smart representation can color elements according to that property. The software can also display layer names and the number of elements assigned to each layer.

Guide and Key Points

• Set default IFC layer names: Revit’s DWG export settings show layer mappings for Revit categories, but this dialog does not define IFC export options.
• Edit the Revit input file: To change IFC layer mappings, locate the Revit input file in the user’s Application Data/Roaming/Autodesk/Revit folder. Make a backup before editing it.
• Specify a layer-mapping text file: In the input file’s catalogs section, update the DGN property to point to a text file that defines the exported layer names. Check that the file name and path are correct, then save the input file and restart Revit.
• Verify the export: Re-export the model and inspect its layer properties in BIMcollab Zoom. The video’s example updates the names to follow ISO 13567 and uses Uniclass 2015 for the layer classification field.
• Override layers for selected elements: Add an IFC Presentation Layer parameter in Revit at the type or instance level, then assign a layer value that follows the naming rules. For loaded families, the parameter can also be set at the family level. This allows default mappings to be applied broadly, with specific elements or types overridden as needed.

Main Speaker and Source

A single instructional narrator from Practical BIM Resources.