From BlenderWiki
PART V - LIGHT
Lighting is a very important topic in rendering, standing equal to modelling, materials and textures. The most accurately modelled and textured scene will yield poor results without a proper lighting scheme, while a simple model can become very realistic if skilfully lit. Lighting, sadly, is often overlooked by the inexperienced artist who commonly believes that, since real world scenes are often lit by a single light (a lamp, the sun, etc.) a single light will also do in computer graphics. 光源的使用和前期的建模，材质选取一样重要。没有一个合适的光源，就算用最精确的模型和材质做出的图象也只能产生不理想的结果 ，而一个非常简单的模型经过高超的光源技术处理也能变的非常真实。 悲哀的是光源的使用经常被一些没有经验的画师所忽视，他们一般会这么想，既然现实世界中的图景只是被一个光源（一盏灯，太阳，等等）照亮，那么一个光源也能在电脑图象处理方面做同样的事情
This is false because in the real world even if a single light source is present, the light shed by such a source bounces off objects and is re-irradiated all over the scene making shadows soft and shadowed regions not pitch black, but partially lit. 这样是不对的，因为在现实世界中，即使只有单光源，单光源发出的光线遇到物体会发生反射，将光线反射到整个场景上，使得影子很柔和而不是漆黑一片，是有些光亮的。 The physics of light bouncing is simulated by Ray Tracing renderers and can be simulated within Blender by resorting to the Radiosity (chapter_radiosity) engine. 真实的光线反射可以通过光线跟踪渲染器进行模仿，在Blender里可以通过光能传递功能得以实现。
Ray tracing and radiosity are slow processes. Blender can perform much faster rendering with its internal scanline renderer. 光线跟踪和光能传递都是缓慢的步骤。Blender通过其内部的扫描线渲染器，可以使渲染的速度大大提高。
A very good scanline renderer indeed. This kind of rendering engine is much faster since it does not try to simulate the real behaviour of light, assuming many simplifying hypothesis. 事实上是个很好的扫描线渲染器。这种渲染工具速度快很多，是因为它不是试图去模仿真实光线，而是采取了许多简单的假设。
In this chapter we will analyse the different type of lights in Blender and their behaviour, we will analyse their strong and weak points, ending with describing a basic 'realistic' lighting scheme, known as the three point light method, as well as more advanced, realistic but, of course, CPU intensive, lighting schemes. 这一章里，我们将分析Blender的不同类型的照明和他们的功能，将分析他们的优缺点， 最后以描述一个基础的逼真的照明方案结束。有被称为三点光的方法，同样有高级的，逼真的但当然很占CPU资源的照明方案。
Chapters
