Manual/PartV/Ray Shadows
Wikipedia，自由的百科全书
As opposed to Buffer Shadows, Ray Shadows are obtained by casting rays from a regular light source, uniformly and in all directions. The raytracer then records which pixel of the final image is hit by a ray light, and which is not. Those that are not are obviously obscured by a shadow.
与缓冲阴影不同，射线阴影通过从一个规则的光源在所有方向上均匀地投射光线来获得、射线追踪会纪录最终图像的哪些象素被射线光击中，哪些没有。没有被击中的将被阴影明显地模糊化。
Blender lets you choose between different kind of Lamp types, and each of these cast rays in a different way. For example, a Spot Light cast rays uniformly and in all directions within a cone; on the other side, the Sun Light cast rays from a infinitly distant point, with all rays parallel to the direction of the Sun Light.
Blender让用户在不同的灯光类型之间选择，每种类型都能在不同的方向上投射射线。例如，一个聚光灯在一个圆锥体内的所有方向上均匀地投射；另一方面，日光从一个无限远处投射，并且所有的光线都平行。
Because a number of rays is cast by each lamp of your scene, Ray Shadows are way slower to compute than Buffer Shadows are, but are more sharp on the border of lit/unlit areas of a surface. In order to activate Ray Shadows for a given light source, go to the Lamp Buttons menu, and in the Shadow and Spot tab, activate the Ray Shadow button, as showed in The Shadow and Spot tab
因为你的场景中的每个灯都会发射光线，所以射线阴影的计算比缓冲阴影要慢一些，但是在照亮/非照亮区域的边界会锐化一些。为了对一个给定的光源激活射线阴影，进入灯光按钮组菜单，在阴影和聚光灯面板中按下射线阴影按钮，如图阴影和聚光灯面板所示
All the Lamp types, except the Hemi Light one, can produce Ray Shadows. At the moment, only the Area Light provides supplementary buttons and settings relative to Ray Shadows. Please consult the Area Light buttons in Chapter xx and the Figure Area Light Options. for a view of Area Light's Shadow and Spot tab.
除了半光灯之外，所有的灯光类型都能产生射线阴影。只有区域灯光提供辅助按钮和与射线阴影相关的设置。关于区域灯光阴影和聚光灯面板，请参考XX章中的区域照明按钮和图区域灯光选项。
Of course, as with any other Raytracing related feature of Blender, you also have to activate the Ray button, in the Render tab of the Scene (F10) Buttons menu, as shown in The Render tab, along with the Shadow button, common to the Buffer Shadows method.
当然，使用Blender其它的射线追踪向广特性，你也必须激活场景（F10）按钮组菜单的渲染面板中的射线按钮。正如渲染面板所示，在缓冲阴影中阴影按钮的使用方式也是相同的。
|
