1·A very good example of directional light is sun light.
一个比较好的例子就是太阳光。
2·A directional light doesn't have a position, only a direction.
定向光没有位置，只有方向。
3·Finally, the directional light gives each side a different color.
最后，定向光使每面都具有不同的颜色。
4·If the light is a Spot or a Directional light, this must be a 2d texture.
如果灯光是聚光灯或方向光，这必须是一个2d纹理。
5·Base pass renders object with one per-pixel directional light and all SH lights.
基础通道用一个逐像素方向光和所有球面调和光渲染物体。
6·Shadow softness fade based on the distance from the camera. Directional light only.
阴影柔化是根据到相机距离进行淡出的。只用于方向光。
7·The directional light was a good choice to generate nice, smooth shadows and caustics.
方向灯时很好的产生漂亮和柔和的阴影和焦散的灯光。
8·Finally, in Forward rendering path, only the brightest directional light can cast shadows.
最后，在正向渲染路径，只有最亮的平行光可以投射阴影。
9·To accomplish this I decided to use a targeted directional light, which was used as a sun.
为了完成这一步，我决定使用一个目标方向灯来作为太阳。
10·First it is necessary to define the light's position (or direction for a directional light).
首先我们需要去定义光的位置(后者为方向光定义一个方向)。