largeish

As mentioned above in the directional lights section, the rendering of shadows for directional lights is an approximation that allows us to use a single render to cover a largeish area with shadows.

你也可使用着色语言作为技术基础来处理阴影投射体和接收体材质来更复阴影算法，比如支持自投影深度阴影贴图。