Navisworks IFC Export

Exporting IFC from Navisworks

IFC export from Navisworks is a brand new feature in the Geometry Gym plugin.

Existing offerings to export IFC generate huge tessellated models in a primitive way, leading to huge files that aren't practical to use. The Geometry Gym plugin detects extrusions to decimate the file size (in particular for structural models), and permits user nomination of property templates to filter/control properties that are exported.

We have a list of improvements we want to add to this new feature. If you have suggestions or problems, please contact [e-mail] (if you can share representative problem files, this helps a lot).

Improvements we've identified include:

• Recognition of IfcExportAs and IfcExport properties.

• Merge of IFC with existing file

• Support properties beyond Text

• Creation of property template file from active Navisworks document.

• Identify Revit Sub Categories (if possible)

• Support complex properties (such as bounded vales).

• Support Ifc Property Templates in Revit text format.

IFC Export

Configuration of the exported IFC is controlled by two configuration files. For project specifc settings, the plugin will search the navisworks document folder for configuration files. If it can't find them, the plugin will search the default folder for these, C:\Users\USERNAME\AppData\Roaming\GeometryGym\NavisWorks Note if you've loaded the Navisworks plugin and closed Navisworks, a configuration file will be created at C:\Users\USERNAME\AppData\Roaming\GeometryGym\ggNavisIFC.config You can edit this xml file to change the default folder location or FileName of each configutation file.

Class Mapping

For convenience, we support the nomination of class mapping consistent with Revit IFC export. At present this lists Revit categories and sub categories, although we haven't identified how to recognize sub categories in Navisworks yet. The mapping relates to the Type property and isn't constrained to revit categories.

We publish our version of this file here: https://github.com/jmirtsch/RevitIfcClassMap/blob/master/RevitIfcExportClassMap.txt

Property Template

At present we support nomination of property templates in ifc format. Here's a sample xml format of this. At present only text properties are supported, we will enable lengths, quanties etc ASAP, as well as support of the revit text file nomination of properties. Default expected filename is PropertyTemplates.ifcxml

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ifcXML xsi:schemaLocation="http://standards.buildingsmart.org/IFC/RELEASE/IFC4_1/FINAL/XML/IFC4x1.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.buildingsmart-tech.org/ifc/IFC4x1/final">
  <IfcProjectLibrary>
    <Declares>
      <IfcRelDeclares>
        <RelatedDefinitions>
          <IfcPropertySetTemplate Name="Identification" TemplateType="pset_occurrencedriven" ApplicableEntity="IfcElement">
            <HasPropertyTemplates> 
              <IfcSimplePropertyTemplate Name="Mark" TemplateType="p_singlevalue" PrimaryMeasureType="IfcIdentifier" />
              <IfcSimplePropertyTemplate Name="WBS" TemplateType="p_singlevalue" PrimaryMeasureType="IfcIdentifier" /> 
            </HasPropertyTemplates>
          </IfcPropertySetTemplate>
        </RelatedDefinitions>
      </IfcRelDeclares>
    </Declares>
  </IfcProjectLibrary>
</ifcXML>