Realistic architectural visualizations using IfcOpenShell and free open source software

From time to time we get reports of people using IfcOpenShell to create visualizations of their architectural IFC models. I figured it was about time to take IfcOpenShell for test drive myself and see how it performs for creating architectural visualizations. I used the build of IfcBlender that is available on GraphicAll and imported this IFC file. A lot of sample IFC files are not that detailed to create interesting interior visualizations, but the FZK haus from EliteCAD is an exception and has quite a detailed interior. Blender has been used to quickly slap some materials onto the model, other than that no real adjustments have been made. The model has been rendered in LuxRender.

What has been discovered after taking IfcOpenShell for a test drive:

• IfcOpenShell is making some great progress and is able to import the vast majority of the geometry successfully ¹
• UV coordinates are generally not present in IFC files, making them perfect for the use of procedural materials
• The fact that only blank materials are assigned in IfcBlender is not such a problem since one would probably have to redefine them anyway for the rendering engine
• The fact that there is no normal smoothing for curved surfaces is quite appearant and has priority to be fixed
• Often objects contain multiple parts, these parts should be preserved to make assigning different materials to different subsets of the meshes easier ²
• Mapped representations should result in instanced geometry to reduce memory usage and limit manual work involved in finetuning the meshes ²

I would love to hear your comments and hear how IfcOpenShell fits into your workflow.

¹ If you want to get an idea of the progress IfcOpenShell is making, compare this wireframe view of the FZK haus to an import done only a month ago by Rafael Moya.
² For example consider the following representation (with apologies for the IFC lingo):

#100 = IFCSHAPEREPRESENTATION(#13, 'Body', 'MappedRepresentation', (#101, #102, #103, #104, #105));

#101 = IFCMAPPEDITEM(#106, #107);

#106 = IFCREPRESENTATIONMAP(#108, #109);

At this moment this results in one mesh with id #100. An alternative would be to mesh the five representations that are referenced by #90-#94 [indeed, one of them is #109] seperately and share them amongst the objects that reference them.