Working with BIM file

Overview

When working with BIM files it is recommended to separate the different parts of the scene into more modular pieces.

In general, we suggest separating the building "structure" from the building "assets". Structure would refer to slabs, floors, ceilings, walls, doors, windows etc. While assets would refer to the HVAC, plumbing, furniture etc.

When dealing with multi-storey structures, we recommend that each storey gets exported individually.

Modularisation Example

Example IFC hierarchy:

• IfcProject/ProjectHouse

  • IfcSite/House

    • IfcBuilding/House

      • IfcBuildingStorey/Storey-0

        • IfcAnnotation/Annotation-0

        • IfcSlab/Slab-0

        • IfcSlab/Slab-1

        • IfcWall/Wall-0

        • IfcDoor/Door-0

        • IfcWindow/Window-0

        • IfcFurniture/FurnitureGroup

          • IfcChair/Chair-0-0

          • IfcChair/Chair-0-1

          • IfcTable/Table-0-0

          • IfcTable/Table-0-1

      • IfcBuildingStorey/Storey-1

In this example, assume we have a basic IFC file with the above structure and only concerned with the first storey.

Modularising this would result in 3 glb files:

• Storey_0.glb

• Chair_0.glb

• Table_0.glb

Contents of Storey_0.glb:

• IfcBuildingStorey/Storey-0

  • IfcAnnotation/Annotation-0

  • IfcSlab/Slab-0

  • IfcSlab/Slab-1

  • IfcWall/Wall-0

  • IfcDoor/Door-0

  • IfcWindow/Window-0

  • IfcFurniture/FurnitureGroup

Storey_0.glb will only contain the structure of that storey. We do not include annotations or furniture.

Contents of Chair_0.glb

• IfcChair/Chair-0-0

Contents of Table_0.glb

• IfcTable/Table-0-0

For repeating furniture, we only need to export one of each type.

See Tips to get your 3D assets works in Spatialwork for details on exporting them properly.

Exporting to GLB

Once we've planned how the scene is going to be modularised, the next step is to actually export it as a .glb file.

Revit 2022 (untested/paid)

To export objects to glb in Revit 2022, we'll make use of a plugin from the Autodesk Store called SimLab GLTF Exporter for Autodesk® Revit®

Blender 3 (free/hard)

In this section we will explore how to export a glb file using Blender from an IFC file.

1. Export BIM file as IFC file

2. Install the BlenderBIM Addon for Blender 3.3 LTS

3. Import IFC file into Blender

4. Select objects to export with modularisation in mind.

   1. Make sure to select the entire hierarchy of the object and not just the parent node.

   2. If it a repeatable asset (furniture) ensure that they follow Tips to get your 3D assets works in Spatialwork

5. Go to File -> Export -> glTF 2.0

6. Browse to directory to save

7. On the right panel of the export window

   1. Twirl down Include

   2. Check Limit to Selected Objects

8. Name the file

9. Export