From BIM to VR - The design and development of BIMXplorer

Doctoral thesis, 2016

The architecture, engineering and construction (AEC) industries are currently undergoing a change from a drawing-based form of information exchange to a model-based. Using the concept of Building Information Models (BIM), the content produced by architects and designers has evolved from traditional 2D-drawings to object-oriented 3D-models embedded with information to describe any building in detail. This, in turn, has opened up new possibilities of using real-time visualization and Virtual Reality (VR) as a tool for communication and understanding during the design process. However, as primarily created to describe a complete building in detail, many 3D dataset extracted from BIMs are too large and complex in order to be directly used as real-time visualization models. Because of this, it is still difficult to integrate VR and real-time visualizations as a commonly used tool during the design process. The recent introduction of a new generation of Head-Mounted Displays (HMD) has also made the situation even more challenging. Although these new types of VR devices offer huge potential in terms of realism, sense of scale and overall suitability for design and decision-making tasks, they are also far more demanding when it comes to real-time rendering performance. In order to address the current situation this thesis contributes with the design and evaluation of a new software application that provides a simple interface from BIM to VR. Following a design science research approach this application has been developed in order to fulfil a set of requirements that has been identified as important in order for VR and real-time visualization to become an everyday used tool for design and communication during the building design process. Along that path, three new technical solutions have been developed: -An efficient cells- and portals culling system automatically realized from BIM-data. -An efficient approach for integrating occlusion culling and hardware-accelerated geometry instancing. -An efficient single-pass stereo rendering technique. The final system – BIMXplorer – has been evaluated using several BIMs received from real-world projects. Regarding rendering performance, navigation interface and the ability to support fast design iterations, it has been shown to have all the needed properties in order to function well in practice. To some extent this can also be considered formally validated, as the system is already in active use within both industry and education.