||BIMSERVER.Org – An Open Source IFC Model Server
||Jakob Beetz, Leon van Berlo, Ruben de Laat, Pim van den Helm
||In this paper we introduce the ongoing development of a free and open model server to persist, maintain and manage instance models of the Industry Foundation Classes (IFC) format. By using open standards, robust existing software frameworks, best practices and workflows accepted in the broader software engineering world as the basis of our framework, we hope to gain traction within the research and development community by creating a completely open reference implementation that is free to use and extend within individual research projects and commercial applications. By providing an open and extendable architecture around a robust and performant kernel we hope to be able to encourage the integration of many earlier and current efforts that have been undertaken in the field of IFC-based model processing.We describe the set of features implemented so far and give an outline of a roadmap for future developments. Some of these implemented features include: User management, up- and downloads of models, a check-out and check-in mechanism and versioning. As part of this versioning mechanism we show a tree comparison algorithm that allows the creation of version-deltas we refer to as change sets. These change sets are used to minimize the amount of traffic to and from the central repository by only communicating its differences. All server-side functionality described here is exposed through a web-service API which has been used to implement web-based and standalone client applications. A filtering mechanism allows the extraction of sub-models such as specific element types. We show how we transform original STEP part 11 EXPRESS schemas into a Meta-Object-Facility (MOF), and store them in XMI/EMF models. Furthermore, we describe how our framework provides a mapping to a BerkeleyDB database facilitating its rich set of features. We demonstrate how we use a suite of more than 1600 IFC models from various sources to test the integrity of the framework. To demonstrate that our framework works efficiently enough for real-world building model scenarios, we provide some performance indicators using this extensive suite of test models.We finish our report by laying out some of the ideas and plans for the future development of the server which include query languages (for the definition of IDMs etc.), a viewer (e.g. for the visualization of differences between model versions) and the integration of other model schemas such as the ISO 12006-3.
|Year of publication:
||IFC, model server, BIM, CAD, collaboration
Jakob Beetz, Leon van Berlo, Ruben de Laat, Pim van den Helm (2010).
BIMSERVER.Org – An Open Source IFC Model Server. CIB W78 2010 - Applications of IT in the AEC Industry,