Shading for Fourier volume rendering

Abstract

The work presented here describes two methods to incorporate viable illumination models into Fourier Volume Rendering (FVR). The lack of adequate illumination has been one of the impediments for the wide spread acceptance of FVR. Our first method adapts the Gamma Corrected Hemispherical Shading (GCHS) proposed by Scoggins et al. (2001) for FVR. We achieve interactive rendering for constant diffusive light sources. Our second method operates on data transformed by spherical harmonic functions. This latter approach allows for illumination under varying light directions. It should be noted that we only consider diffuse lighting in this paper. We demonstrate and compare the effect of these two new models on the rendered image and document speed and accuracy improvements.