In my research, I found this research paper, how they implemented B-Spline Surfaces in TUM Open Infra Platform.
There was also this interesting table:
Before that, I did not know that TU Munich was developing an Ifc-Viewer. Here is their git repository: https://github.com/tumcms/Open-Infra-Platform
TUM Open Infra Platform (OIP in short) is a software for checking and viewing IFC data. It comes with its own EXPRESS parser and C++ classes generator.
Had someone made experience with it?