Computer Graphics

High-Dynamic Range Systems

Real scenes and real photographic images exhibit a much larger dynamic range than current technology provides for. This project investigated how images with high dynamic range (HDR) can be acquired and how images with high dynamic range can be displayed on current hardware. One result is a system that can acquire HDR images at video rates. A collaborative project led by UBC and with G. Ward and other researchers at McGill and York University as well as several companies resulted in a new HDR display system. The technologies were being commercialized by the startup Brightside Technologies. Dolby recently acquired this company. We also presented a first high-dynamic range projector and dealt with user interface issues on high dynamic range displays.

Real-time Rendering

This research investigated multiple methods to make creating new images more efficient, through image-based methods, new ways to compute shadows, dealing with very large models, levels of detail, and the results of global illumination computations.

3D Scanning

Several commercial solutions exist for scanning of 3D objects. The result is a geometric model of the object. Although impressive results have been demonstrated, user intervention is still required to generate complete object models. This project addresses the problem with techniques that check during acquisition for missing or badly sampled parts and direct the acquisition device to capture new views of such parts.

Ray Tracing

This work presented the first ray tracing method for triangular free form surfaces, which are becoming more common in CAD applications. Another important contribution introduces a compact and efficient description of complex trimming curves such as those created by combining objects described by free form surfaces. We also present an optimization for the traversal of bounding volume hierarchies, which speeds up the traversal by at least 50% and another speed-up method based on subdividing directional space.

Global Illumination

These publications discuss new methods to deal with shadow boundaries for area light sources and a massively parallel method to compute radiosity solutions on distributed memory machines with hundreds of processors. Key contributions include a distributed visibility computation technique that consumes less bandwidth compared to other approaches an efficient dynamic load balancing technique.