Geometry shadow maps

ABSTRACT

The standard shadow map method works well in the interior area of shadows but not along the boundaries. Although many methods have been proposed to address this limitation, they suffer from various limitations. In this paper, we propose the geometry shadow map method to improve the quality of shadow boundaries. Our idea is to represent each object by one or more triangle fans and its silhouette by the perimeters of the triangle fans. The geometry shadow map is used to access the object geometry information by storing the index information of these triangle fans. Our method changes the shadow calculation problem to a line-triangle intersection problem, which can be represented by matrix-vector multiplications. This avoids reconstructing the silhouette edges or computing and rendering shadow volumes. We present some interesting implementation tricks and discuss the performance of a GPU implementation of the proposed method.

References

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Index Terms

• Computing methodologies

  • Computer graphics

    • Image manipulation

      • Texturing