Bilateral Filtered Shadow Maps

Abstract

We present a novel shadow smoothing algorithm using the bilateral filter. From the observation that shadow leaking, which is found often in filter based approaches, occurs at depth discontinuity seen from the viewpoint of the eye, we apply the bilateral filter which is conceptually a product of two Gaussian filters, one for smoothing the shadow map and the other for handling depth discontinuity. Consequently the bilateral filtered shadow maps can smooth the shadow boundaries effectively and do not suffer from shadow leaking artifacts.