TOWARDS PROBE-LESS AUGMENTED REALITY - A Position Paper
Claus Brøndgaard Madsen, Michael Nielsen · 2008
Abstract: The main problem area for Augmented Reality is ensuring that the illumination of the virtual objects is contin-uously consistent with the illumination in the real scene. State of the art in the area typically requires the real scene illumination conditions to be captured as a High Dynamic Range environment map. The environment map is then used for shading and shadowing. Handling the real and the virtual shadows and their interaction is the single most difficult aspect. This paper presents a completely different approach to determining the illumi-nation conditions in the real scene. Based on an assumption that the scene is outdoor we automatically detect shadows in the image and use this information to determine the ratio of sky irradiance to sun irradiance. We then present how to convert this information into radiance levels for both the sky and the sun. When combined with a computation of the Sun’s position based on date, time and information about position on the Earth, we arrive at a full illumination model applicable for rendering virtual objects into real scenes. 1