The Irradiance Volume

This paper presents a volumetric representation for the global illumination within a space based on the radiometric quantity irradiance We call this representation the irradiance volume Although irradiance is traditionally computed only for surfaces we extend its de nition to all points and directions in space The irradiance volume supports the reconstruction of believable approximations to the illumination in situations that overwhelm traditional global illumination algorithms A theoretical basis for the irradiance volume is discussed and the methods and issues involved with building the volume are described The irradiance volume method shows good performance in several practical situations keywords computer graphics global illumination realistic image synthesis light eld