Immersive Architectural Daylighting Design Experience

We present an application of interactive global illumination and spatially augmented reality to architectural daylight modeling that allows designers to explore alternative designs and new technologies for improving the sustainability of their buildings. Images of a model in the real world, captured by a camera above the scene, are processed to construct a virtual 3D model. To achieve interactive rendering rates, we use a hybrid rendering technique, leveraging radiosity to simulate the inter-reflectance between diffuse patches and shadow volumes to generate per-pixel direct illumination. The rendered images are then projected on the real model by four calibrated projectors to help users study the daylighting illumination. The virtual heliodon is a physical design environment in which multiple designers, a designer and a client, or a teacher and students can gather to experience animated visualizations of the natural illumination within a proposed design by controlling the time of day, season, and climate. Furthermore, participants may interactively redesign the geometry and materials of the space by manipulating physical design elements and see the updated lighting simulation.

Our daylighting design tool is implemented in 3 systems. First, it is a desktop software daylighting tool for widespread use in architectural design. Second, it is a small-scale, low-cost virtual heliodon, appropriate to be installed in the conference room of architectural design practice for regular use. Third, it is a full-scale, immersive design environment in which participants can gather to experience animated visualizations of the natural illumination within a proposed design. Our project will also leverage the computational resources at the new Computational Center for Nanotechnology Innovations (CCNI).