Introduction

Building Information Models (BIM) are typically Object Oriented and tend to be large. For example the Industry Foundations Classes (IFC) have more than one thousand different classes. Because the BIMserver has been written in Java (an Object Oriented Language), it is very usefull to have actual Java classes in the used BIM model (for now, the BIMserver uses IFC internally), this is where the Eclipse Modeling Framework (EMF) comes into play.

IFC Schema

Most BIM meta models are described in a file format. As IFC is based on STEP/EXPRESS technology, the schema is available as an .EXP file. This file has been converted to an EMF ECore file with the BuildingSMARTLibrary (part of BIMserver project).

Generating Code

The EMF framework generates Java classes with the given ECore file, these classes are used to store BIM models and passed to the database layer.

Caveats

If you load a model from an IFC-Step file, the String values of floating point numbers are being stored as a String as well. If you change the float values programatically, you should update (or clear) the string value.