完成延迟光照处理后，摄像机是否应清除模板缓冲区？
When using Deferred Shading or Legacy Deferred Lighting, the G-buffer and lighting passes use the stencil buffer.
By default contents of the stencil buffer are preserved (not cleared) and end up containing information related
to lights. Setting this property to true makes
stencil be cleared to zero after the deferred light pass is done.
一般说来，如果您使用了延迟着色摄像机和带遮罩的 UI 元素（请参阅 UI.Mask），则需要清除模板
缓冲区。