Ambient-Occlusion-Animation 环境闭塞动画

Ambient Occlusion Animation 环境闭塞动画
By Dani Ohayon
作者：Dani Ohayon
Software used/使用软件:
3ds Max
翻译by：yipinsucai.com

The purpose of this workflow is to generate a lighting system that will produce good indirect illumination without the use of Final Gather.
此工作流的目的是创造一种照明系统,能产生不错的间接光照而不使用最终聚集。
The point is to be able to animate objects and get a good updated lighting solution for each frame. We will be using AO with the Custom Ambient Light Color map.
关键是能找到一种不错的方法：让动画物体的每帧获得先进的照明效果。我们将使用AO参数栏里的Custom Ambient Light Color map。
The map will be a spherical projection of a mr Physical Sky that will align with the scene's Sun light direction. We will use this utility to mass update our A&D material.
这这个贴图是一个mr Physical Sky，能匹配场景里的太阳光方向，它将球形包裹我们的场景。我们将使用这个实用的工具大规模更新我们的A&D材质。
The combination of the map and AO gives the scene the illusion of daylight indirect illumination that takes into calculation the proximity between objects (Fig.01).
结合贴图和AO，让场景里的物体产生日光的照明并根据物体的距离计算出间接照明(Fig.01)。

Fig. 01
Materials, Gamma and Exposure/材质，伽马和曝光
This workflow uses the AO map option in the A&D material, so it is crucial that all your materials are A&D (no Pro Mat stuff).
这个工作流程使用A&D材质里的AO MAP选项,因此,至关重要的是,你所有的材质必须都是A&D材质球(没有Pro材质)。
Now, just try to follow Fig.02 – 03 to start with and change it later as you see fit. The Unitless Physical scale use is important in this workflow; it will work accurately with the image brightness and will look normal in the Material Editor, so you don't get over-exposed material previews, which makes it hard to work with.
现在,只要试着照Fig.02 - 03，参考着修改参数,你看着办吧。在这个工作流程里Unitless Physical scale 很重要，它将使图像的亮度和材质编辑器看起来正确,所以你不要让这些材质过爆，会导致很难使用。

Fig. 02

Fig. 03
Create a few objects on a plane so you can test shadows, AO and lighting. Make the objects life sized so you can see how they will work with a real world scale.
创建一些物体在一个平面上,这样你就可以测试的影子,AO和照明。使对象比例像真实世界一样,这样你就能看到它们是什么运行机制。
If your objects are too small or too big you'll get extreme results (too much or not enough shadows and light). The large sphere in my scene is 12' in diameter; you can see the RPC on the side for scale.
如果对象是太小或太大的你会得到极端的结果(太多或太少的阴影和光)。场景里的大球是12英尺,你可以看到旁边站着的人物参考来做对比。
Now add a daylight system and make sure you create a mr Physical Sky shader in your environment. You can make a test render now and save it for a later comparison.
现在,添加一个日光系统,确保您已经创建一个物理的天空材质在您的环境中。你可以做一个测试渲染现并将其保存作为以后渲染的参考。
Now we will replace the Skylight and FG solution with our AO Ambient Light map. We do that by the use of a bitmap in the Custom Ambient Light Color.
现在我们将用AO环境光贴图取代天光和FG solution 。我们用一张位图自定义环境光色。
The bit map in this example was generated using a WrapAround (Lume) shader in the Lens slot (Render Settings > Renderer) in an empty scene with Daylight system and a mr Physical Sky in the environment map.
这个示例的天空图片是用一个Lens slot 中加了一个WrapAround (Lume) shader (Render Settings > Renderer)放在一个空场景中，并且打了一个日光系统+一个MR物理天光环境渲染而成的。
The camera was pointing at the straight horizon. After some blurring in Photoshop, it should look like this (Fig.04).
照相机对准地平线。后期在Photoshop中用了一点模糊,它看起来应该是这样的(Fig.04)。

Plug this map into the AO Ambient map of one of your materials (in the Material Editor, not the utility yet). To start, set up your map as shown in Fig.05.
把这个贴图映射到AO环境地图中(在材质编辑器中)。首先,设置你的贴图如Fig.05所示。

Fig. 05
Then open the utility and press the Load Ambient Map button in the AO section to load an instance of that map (you can find it if you click on Browse From: Scene). Press Update Map to populate this map in your entire scene (Fig.06).
然后打开utility 点击Load Ambient Map按钮用关联的方式载入这张贴图(你可以找到它,如果你点击浏览从:场景)。点击 Update Map 把贴图载入到场景里(Fig.06)。

Fig. 06
U Offset
As you can see from the AO map, it suggests the location of the sun in your sky. So this setting should be adjusted to match the location of your actual sun. In my opinion, the best way to do that is to switch to Top view and do test renders of a sphere.
正如你从AO贴图上所看到的,它显示太阳在天空的位置。所以这个应该设置为匹配你实际场景中的太阳的位置。在我看来,最好的办法是,切换到顶视图做测试渲染一个球体。
The left sphere was rendered with the actual Sun light only. The two spheres at the center are with the AO map only (with the respective setting of U offset) and the last one shows the combination. (Fig.07).
左边的球是只只用了一个你打的那个太阳光，中间的两个球只使用了AOmap，分别调整了U offset设置，最后一个球员是合成后的效果。

Fig.07
Now make sure you turn off Final Gather and render (Fig.08).
现在关掉Final Gather 然后渲染。

Fig.08
At this point you might want to switch between the two solutions for quality and accuracy comparisons (AO > FG).
现在你可以调出两种模式的渲染结果做一个对比。
To do this quickly you can turn on FG, and in the utility switch to Global Ambient and force it. This will make use of the color swatch in your environment – just make sure it's black.
要切换回FG很容易，你只要打开FG,在utility切换到Global Ambient。这需要确保你的环境色是黑色。
I hope you found this tutorial useful!
希望这篇教程对你有用！
翻译by：yipinsucai.com