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DDScad IFC Export

Introduction to IFC Export

We can export the content of a drawing to IFC (Industry Foundation Classes), which is a standard format for BIM models. Before exporting, you should turn off the display of elements that should not be included in the IFC file.

Exporting to IFC

Instructions

  1. Open the dialog for Settings Gemini Terrain... - Project - IFC
  2. Optionally enter the origin for the BIM project and click OK
  3. Select File - Export - IFC...
  4. Select the desired IFC version
  5. Click Browse... and enter the name of the file and click Save
  6. Select exchange requirements in the dropdown menu, typically Terrain Export 3D
  7. Click Export and open

Layers and Application Layers

Note

There is currently no support for exporting the calculated terrain grid. If a triangular mesh is the data basis for the terrain grid, this will be included. If the base data for the terrain grid are contour lines or point clouds, nothing will be exported.

Other objects are exported as: * IfcBuildingElementProxy (version IFC2x3) * IfcGeographicElement (IFC4)

Models

Masses and Layers in Excavation Pit

Masses are displayed as volumes. This is done by calculating a triangular mesh for the bottom and top of the mass, and then closing the triangular meshes. These volume objects are not 100 percent exact, but the display accuracy is set with Density for drawing masses in the excavation pit dialog.

Note

Note that this number is related to the setting Grid size used in calculations in Settings Gemini Terrain... - Project - General: This is the grid resolution used to calculate the triangular mesh, so the triangles will never be finer than this setting.

Since the display of these volumes is not completely exact, the usual mass calculation is still used. The correct volume is found as a property (PropertySet), which you can find by double-clicking on the relevant mass.

In addition, a function has been created that cleans up the triangular mesh by merging triangles that lie in a plane. This improves performance and reduces storage space, especially in masses with large flat areas.

The display of area masses is also now presented as a triangular mesh – naturally without volume.

Tree Structure of Elements in the IFC File

The IFC file is divided into a tree structure. This tree may look slightly different depending on whether you use Solibri, Navisworks, DDS, or other programs, but the essence should be the same:

  • Masses end up in a container called "ExcavationMasses"
  • Layers are sorted in "ExcavationLayers"

The display of these can be turned on and off – this also depends somewhat on the choice of IFC viewer.

Tree structure in IFC view

Example of how this tree structure can look in DDS's IFC viewer

Project Properties

When we export to IFC4, the following information is included:

  • Map conversion information
  • Coordinate reference system information
  • Longitude and latitude (site longitude and latitude)