3DIR: three-dimensional information retrieval from 3D building information modelling environments.

More and more information is being packed into Building Information Models (BIMs), with the 3D geometrical model serving as the central index to lead users to the many other types of building information. The Three-Dimensional Information Retrieval (3DIR) project investigates information retrieval from such environments, where information or documents are linked to a 3D artefact. In these situations, the 3D visualisation or 3D geometry of the building can be exploited when formulating information retrieval queries, computing the relevance of information items to the query, or visualising search results. Following reviews of literature in BIM/CAD and information retrieval, a clear gap was identified in the practice of information retrieval from BIM/CAD systems. End users were consulted to ascertain the precise user requirements in such an information retrieval system. Scenario-based design was adopted to design a software prototype. The 3DIR system was developed as an add-in under the Autodesk Revit BIM platform. The 3DIR prototype creates an index of all text data attached to the 3D model. The user is able to search for information by selecting specific 3D objects, by keyword and by specifying particular 3D regions of the model. Relationships between 3D objects are also used to rank search results. Search results are displayed by highlighting 3D objects in the 3D model. Findings from the evaluation of the prototype demonstrate its usefulness but suggest directions for future development. It is concluded that a tight coupling between text-based retrieval and the 3D model is extremely effective in 3D BIM environments.