'Lighting Basics'－－灯光基础 'Lighting Basics' by Yahya Ehsan
原文链接：http://www.3dtotal.com/team/Tutorials_3/lighting_basics/lighting_basics01.asp
We can’t see anything without light. Nature have it own rules, ‘natural rules’ and to reproducing images or animations in 3d/2d space we need to know about the lighting basics; so that our creation in terms of image(s) looks closer to nature. Sometimes we view two colored image and believe them real and on the other side we see multimillion colored image and clearly say it FAKE. It hurts to hear it. Doesn’t it!
（没有光，我们就看不到任何东西。大自然有它自己的法则，“自然法则”被复制到3d或2d空间里的图像或动画中。 我们需要了解关于灯光的基础知识，这样我们创作的图像就能接近自然。有时我们看到双色的图像并相信他们是真实的，而有时我们看到有数百万色的图像，却很肯定的说它假。听上去是难以置信的，但事实不正是这样吗？）
So let’s find out some mainly major or at least key points to not hear that word starting with F. To do so we need to have a clear understanding of the element related to this. To start with let’s have two objects a sphere and a room, and we are in that room. We can’t see anything unless we have a source of light. Just forget for a while about that we have sun or any other source of light. I will be indentifying the elements to learn by heart.
（所以让我们去寻找一些主要的关键点，以免听到那些抱怨之词。为此我们需要对元素间的关系有一个清晰的认识。让我们从两个物体开始：一个球和一个房间，我们在房间里。除非有一个光源，否则我们无法看到任何东西。请暂时忘记我们有太阳或其他光源。我将压缩这些元素以专心学习。） 作者: 火柴盒 时间: 2008-4-25 11:35
1. For an object to be seen in this room let’s bring some light. As we have introduced a light we can indentify two this in the above diagram.
（1.要使房间里的物体能被看见，让我们带来一些光线。
a.Existence of the light on the floor（在地面有光存在）
b.Object（物体）
(我想我不是在开玩笑，让我们开始，接下来...）
(没有光，看不到任何东西）
(光源在左上方）
2. We just said that if there is no light we can’t see anything so as the sphere is blocking the light to reach the floor, so that part will also be not visible.
And this thing is known as shadow and it’s due to sphere that is cutting the light to reach the floor so it’s sphere’s shadow. It’s also known as cast shadow.
（2.我们刚才说过，如果没有光我们不能看见任何东西，因为球挡住了一部分光到达地面，所以那一部分同样应该是不可见的。众所周知，这个部分叫做阴影。它是由于球切断了光到达地面，所以它是球的影子。这也被叫做投影。）
c.shadow（影子）
Let’s bring the light closer; as the light is closer you have notices that the shadow of sphere has become sharper. So, if light is near to the object its shadow will be hard edged [sharper].
(让我们把光源移近一点，随着光源更近了，你会发现球的阴影也变得锐利起来。所以，如果光源离物体近的话，物体的投影会有一个硬朗的边。）
Okay so we have got to know about shadows let’s talk about colors, why we see a color?
（好了，我们已经了解影子了，让我们讨论下颜色，为什么我们能看到一种颜色呢？)作者: 火柴盒 时间: 2008-4-25 11:36
3.Color derives from the spectrum of light (distribution of light energy versus wavelength) interacting in the eye with the spectral sensitivities of the light receptors. So let’s place a pure blue sphere in the room.
(3.颜色是光谱（与波长相对应的光能）与眼睛里敏感的光线感受器相作用的结果。让我们在房间里放一个纯蓝色的球。）
d.color （颜色）
Does it look natural? NO
（你觉着它看上去自然吗？不）
We have; existence of the light on the floor, object, its shadow and color of course, so why it’s not natural. If it’s not then something is missing.
（在地板上，物体上，他们的影子上都有光，当然还有颜色，这就是为什么它不自然的原因。如果不是这样，那么肯定有些东西丢失了。）
Let’s go and find it!
（让我们继续，并发现它！）
4.To understand it more clearly lets paint the room with all pure bright Green color.
（4.为了更清楚的理解它，让我们给房间一点纯净的绿色。）
Does it look natural? NO
（它看起来自然了吗？不）
We know that some part of light is directly in contact with that ground, it comes back, bounces, just like a ball falling from a height. As the bounce of the ball decreases in the height per contact with the ground so does it’s! [Lights] its intensity is decreased per contact.
（我们知道 一部分光是直接照射到地面上的，他又返回来，反弹，就像一个球从高处落下一样。每接触地面一次，球的反弹高度也随之降低，光也一样。每反弹一次，光的强度也随之而降。）
That’s the bounce of the light and its will be getting bit of green 9as the floor is green, so some green will merge to blue and produce a color somewhere between them.
（下图展示的就是是反弹的光线，它有一点点绿，因为地板是绿色的，所以一些绿色会合并到蓝色上，并混合出介于这两者之间的颜色。）
e.light bounce (so we can see the other side of the object as well with only one light)
(光线反弹（所以即使在只有一盏灯的情况下，我们也能看见物体的另一边。）
[The bounce light will be from the brightest part of the ground, not from the shadow side]
（反弹的光来自地面最亮的部分，而不是来自阴影部分。）
5. We claim to say that this is plastic, metal, rubber! How we say so, nature of the object in terms of visual form, is due to its reflective behavior. Explore this topic it’s got its own dimensions
（5.我们宣称那是塑料，金属，橡胶！我们为什么会这样说，物体的本性体现在了视觉形象上，这是因为他的反射现象。在此不深入探索这个主题。）
作者: 火柴盒 时间: 2008-4-25 11:37
6. Okay now let’s take some more earthly colors and see the results. Change the light placement take it to the top of object, take it to the right side.
（6.现在让我们用更常见的颜色来尝试下，看看结果如何。改变光源的位置，将它放到物体的顶部和右侧 。）
6. Let’s increase the intensity, due to more intense light same object is more visible so does its lower part as the bounce is also intensified due to original increase in intensity.
（6.让我们提高光的强度，因为更亮的光，一些物体更加清晰可见了，暗部也一样，因为反弹的光同样被增强了。）
7. Let’s bring some colored light; Orange and green. One from right and other from left same intensities; they have affected the original color of object.
（7.让我们看看一些有颜色的光：橙色和绿色。一个来自右侧，另一个来自左侧，他们强度一样，他们对物体的固有色都有影响。）
8.Objects color is overridden due to the color of the light. Every object has its color but we see due to light so light be the main lead, if it’s colored it will affect the original color. That’s some theatrical lighting focusing your subject. Observe the nature to get more natural images created by you.
（8.因为灯光的颜色，物体的颜色被改变了。每个物体都有自己的颜色，但我们是通过灯光看到他的，所以灯光是主导因素。如果它是有色的，它将影响物体的固有色。这里有一些戏剧性的灯光聚焦在你的物体上。仔细观察自然，你就能创作更真实的图像。）
So that’s it; if you have any queries or questions you can email me
（就到这儿吧，如果你有任何问题，可以email我。）
