Forest, VincentBarthe, LoicGuennebaud, GaelPaulin, Mathias2015-02-232015-02-2320091467-8659https://doi.org/10.1111/j.1467-8659.2009.01488.xEfficiently computing robust soft shadows is a challenging and time consuming task. On the one hand, the quality of image-based shadows is inherently limited by the discrete property of their framework. On the other hand, object-based algorithms do not exhibit such discretization issues but they can only efficiently deal with triangles having a constant transmittance factor. This paper addresses this limitation. We propose a general algorithm for the computation of robust and accurate soft shadows for triangles with a spatially varying transmittance. We then show how this technique can be efficiently included into object-based soft shadow algorithms. This results in unified object-based frameworks for computing robust direct shadows for both standard and perforated triangles in fully animated scenes.10.1111/j.1467-8659.2009.01488.x1111-1120