方差阴影图中的光渗现象消除算法

方差阴影图算法使用概率的方法计算像素被遮挡的上限概率,通过对深度图滤波的方法来有效地减少阴影图算法中的走样问题,但在深度比较复杂的场景中方差阴影图算法会出现光渗现象,即在应该是阴影的区域却有了亮度.文中使用最小-最大阴影图来辅助消除方差阴影图中的光渗现象,在对深度纹理进行滤波的同时生成一个最小-最大阴影图;在实时绘制场景时,利用最小-最大阴影图来辅助判断当前片元是否完全处在阴影区域内部,由此生成更真实、更准确的阴影.该算法可以很容易地添加到已有的方差阴影图算法的片元处理程序中,并且不会对原有阴影的柔和边界以及绘制的帧率产生影响.

Removal of Light Bleeding in Variance Shadow Maps

Variance shadow maps algorithm adopts a probability method to estimate the up-bound of the probability of a pixel falling in shadow,it effectively reduces the aliasing in traditional shadow maps algorithm by filtering the shadow maps themselves.However,this method may cause light bleeding in scenes of high depth complexity,i.e.areas with umbra may receive some light.In this paper,we propose an algorithm of integrating min-max shadow maps with variance shadow maps to remove light bleeding.We construct min-ma...