By the time he had walked three or four miles, every shape in the landscape had assumed a uniform hue of blackness. 此刻，他已经走出三四英里了，田野中所有朦胧的形象都呈现出了一种深浅均匀的黑色。
The idea of switching from the texture to blackness is very straightforward but the real trick is in getting the colors to change based on how the surface is illuminated. 从纹理到黑色的切换的概念是非常直接了当的，但真正地技巧是，在获得颜色中来改变基于表面是如何被照亮的。
