赶单子间隔抽空更新，也算对得起点击的同学。。。。
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作者：James Gurney
翻译：http://blog.sina.com.cn/ts152154539
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Chromatic Shadows, Part 1

The painting below shows a warrior standing on a ledge. He is lit by a slanting bar of light that shines from below.
这幅画显示了一个站在窗台上的战士。他被一道下方来的斜射光照亮。


Note that the cast shadow from his arm is red on the bottom and blue above.
The colored shadows suggest that the scene is lit by two adjacent spotlights, a red one below and a blue one above. This is typical of theater lighting, where two or more colored spotlights cast shadows with chromatic edges.
Tomorrow we’ll take a closer look at chromatic shadows.

注意他的手臂的投影，下红上蓝。
彩色的影子表明，这个场景是被两个相邻的聚光灯照亮，一盏红色的在下方，蓝色的在上面。这是典型的剧场灯光效果，在两盏或更多有色灯影响下，投影边缘染上了颜色。
明天我们将进一步讨论有色阴影。
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Chromatic Shadows, Part 2

As we saw yesterday, adjacent colored light sources result in overlapping colored shadows.
正如我们昨天所看到的，毗邻彩色光源让物体有了交叠的彩色投影。


Here’s another rule of thumb: If you have two light sources of different colors shining on the same form, the cast shadow from each light source will be the color of the other source.
That’s because each colored light shines into the shadow of the other. So when the amber light shines on the cylinder, it casts a shadow that is filled only by the blue light—hence the blue shadow.
Let’s make the scenario even more challenging: What happens to the shadows when you have three colored sources? Here’s the effect from blue, red, and green lights.
这里还有一个法则：如果你有两盏不同色彩的光源，同时照亮一个物体，来自每个光源的投影的颜色将是另外一个光源的颜色。
这是因为每个有色灯都会照到另外一盏灯产生的投影中。因此，当黄灯照到圆柱体上，它的投影区里充满了蓝色光。反之同理。
让我们看看更复杂的场景：当有色光源有3个时，发生了啥？下面是蓝色，红色和绿色的灯光效果。


Note that the cast shadows behind my raised hand and my head are magenta, cyan, and yellow. The yellow shadow on the far right is cast by the blue light. It’s yellow because it is lit by a mixture of green and red. In the realm of light, as opposed to pigment, green and red mix to make yellow.
注意，我举起的手和我头后方的投影分别是洋红、青色、黄色。在最右边的黄色阴影为蓝色光所投射。它呈黄色，因为它是被绿色和红色的灯光共同照亮
（译者注：RGB光色相加
红色+绿色=黄色
绿色+蓝色=青色
红色+蓝色=品红
红色+绿色+蓝色=白色）。
在光色范畴中，和颜料的颜色相减理论相反，G加R是黄色的。（译者：自己拿个19号之类的笔刷去ps里刷刷，会有更不错的发现）

The bright cyan shadow is cast by the central red light. It’s cyan because it contains the blend of blue and green light. Blue and green light mix to make cyan.
亮青色阴影由中央红色灯所造成。青色是因为它被混合的蓝色和绿色光照亮。B加G混合成青色光。

If you’re intrigued by colored light interactions, I’d recommend going to the home improvement or theater lighting store and picking up red, green, and blue lightbulbs that you can put in three different light sockets. The best way to learn this stuff is to set them up and try all sorts of combinations. I took the photo in the New York Hall of Science, which has an interactive setup installed.
如果你对彩色光的相互作用感兴趣，我建议你到你家附近什么的卖个红、绿、蓝色的灯泡。学习这些的最好途径就是自己动手丰衣足食。上面那个照片就是俺在纽约科学馆拍的，那里有这个光色装置。

——————————谢谢观赏——————————