Implementing Planar Multi-resolution Soft Shadows on the Fly

摘要

Projection-based shadow algorithm plays an important role in practical applications of realistic computer graphics for its easiness to be understood and implemented. In this paper, we give a presentation for implementing the algorithm to render various shadows on specific planes by using the stencil buffer of OpenGL. In order to simulate the effect of soft-shadows, a number of points on a given light source are sampled and the blending function of OpenGL is enabled to blend images generated from each sample points. Finally, the accumulation buffer is used for full-scene anti-aliasing to make the shadow more realistic. To pursue different realistic effects, our implementation can control resolutions of the rendered shadows in interactive way.