1. A method of rendering a graphical scene comprising: determining a plurality of functions that contribute to a light transport model of a scene; factoring the plurality of functions into a set of fixed functions and one varying function; determining a first radiance transfer vector that represents the product of the fixed functions in the wavelet domain; determining a second radiance transfer vector that represents the one varying function in the wavelet domain; determining an inner product of the first and second radiance transfer vectors to approximate a radiance of a point x in the scene; and rendering the scene.