Real-Time Global Illumination Using Shadow Radiance

A core unsolved problem in computer graphics is how to compute a global illumination solution for dynamic scenes at real-time frame rates. Global illumination is used to add realistic lighting to scenes by taking into account not only light that comes directly from the light source but also indirectly through reflection by other surfaces. In this proposal, we consider new techniques that aim at computing global illumination in real-time. Many applications, such as training, virtual reality, or entertainment, require the ability to interact with a virtual scene. For instance, a user may wish to move furniture around in an architectural application setting. This necessitates updating the resulting illumination in real-time according to the changes in the scene. However, current techniques for real-time illumination computation are either limited to static scenes or to very simple lighting models, such as point lights with hard shadows and no indirect illumination, which decrease the resulting image quality and realism. This is undesirable and a real-time method for general global illumination is still outstanding. The core reason why present global illumination techniques cannot handle dynamic scenes is the need for costly visibility queries between scene elements. In this project, we will develop a new approach to computing global illumination solutions in real-time, without the need for costly visibility queries. In fact, visibility will be handled implicitly by the algorithm through the use of shadow radiance. We will demonstrate the efficiency of our technique using a game and a design application setting. In both scenarios the illumination will always be updated in real-time according to user interactions (e.g., moving furniture around), which has not been previously possible.