How to support self defined schema?

[FLYPoPo7]

We need to use custom schema. It's has some entity that doesn't exist in official ifc standard like 'IfcTunnel'. How to support entities like this? If it needs to change the code, what code do I need to change?

[martin1cerny]

We use internal code generation tool for this. Otherwise you can implement the extension if you follow the patterns in the code. We used the code generation for IfcRail pilot project which you can see here in IfcRail branch for example. But we tend to wait until the official release of the schema by buildingSMART.

[andyward]

We'll be picking this up officially in #353