Fast, Sub-pixel Antialiased Shadow Maps

dc.contributor.authorPan, Minghaoen_US
dc.contributor.authorWang, Ruien_US
dc.contributor.authorChen, Weifengen_US
dc.contributor.authorZhou, Kunen_US
dc.contributor.authorBao, Hujunen_US
dc.date.accessioned2015-02-23T16:08:36Z
dc.date.available2015-02-23T16:08:36Z
dc.date.issued2009en_US
dc.description.abstractSolving aliasing artifacts is an essential problem in shadow mapping approaches. Many works have been proposed, however, most of them focused on removing the texel-level aliasing that results from the limited resolution of shadow maps. Little work has been done to solve the pixel-level shadow aliasing that is produced by the rasterization on the screen plane. In this paper, we propose a fast, sub-pixel antialiased shadowing algorithm to solve the pixel aliasing problem. Our work is based on the alias-free shadow maps, which is capable of computing accurate per-pixel shadow, and only incurs little cost to extend to sub-pixel accuracy. Instead of direct supersampling the screen space, we take facets to approximate pixels in shadow testing. The shadowed area of one facet is rapidly evaluated by projecting blocker geometry onto a supersampled 2D occlusion mask with bitmasks fusion. It provides a sub-pixel occlusion sampling so as to capture fine shadow details and features. Furthermore, we introduce the silhouette mask map that limits visibility evaluation to pixels only on the silhouette, which greatly reduces the computation cost. Our algorithm runs entirely on the GPU, achieving real-time performance and is an order of magnitude faster than the brute-force supersampling method to produce comparable 32x antialiased shadows.en_US
dc.description.number7en_US
dc.description.seriesinformationComputer Graphics Forumen_US
dc.description.volume28en_US
dc.identifier.doi10.1111/j.1467-8659.2009.01571.xen_US
dc.identifier.issn1467-8659en_US
dc.identifier.pages1927-1934en_US
dc.identifier.urihttps://doi.org/10.1111/j.1467-8659.2009.01571.xen_US
dc.publisherThe Eurographics Association and Blackwell Publishing Ltden_US
dc.titleFast, Sub-pixel Antialiased Shadow Mapsen_US
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