(3dsmax)－－－背景匹配 3dsmax

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'Setting up a background image'－－－－背景匹配

'Setting up a background image' 3!osQ1  

原文链接:http://www.3dtotal.com/team/Tutorials_3/setting_background/setting_background01.asp

Setting up a camera to match a photograph in 3D space can be a daunting task for anyone if you don’t know how to go about it correctly. In this tutorial I will demonstrate a real simple way of matching a camera in 3D studio max to a photograph background for easy compositing.

（设置一个摄像机来匹配一张照片的三维空间，如果你不知道如何正确的处理它，这对任何人来说都将是一项艰巨的任务。在这篇教程里我将在3dsmax中示范一个真正简单的方法来匹配一张照片背景，从而可以简单的进行合成。）

Before going in to the tutorial I am going to assume to know the basics of Photoshop 3D Studio Max and Perspectives
（在进入教程之前，我将假定你知道PS，3dsmax和透视学的基本知识。）
One vanishing point:（一点透视）
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One vanishing point is seen in roads rail tracks and any objects that are made up of lines either directly parallel with the viewer's line of sleepers)

（任何线性的物体，如道路，铁轨，车辙，他们与观察者的视线平行时，会消失于一点。）
Two-Point Perspective:（两点透视）
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Two-point perspective can be used to draw the same objects as one-point perspective, rotated. One point represents one set of parallel lines, the other point represents the other set. Looking at a box from a corner, one wall would head towards one vanishing point, the other wall would head towards the opposite vanishing point.  
（与一点透视类似，两点透视也能被用于描绘旋转的物体。一点消失于平行线的一端，另一点消失于另一端。你可以试着从一个角去看方盒子，一个垂直面朝一点消失，另一面朝相反的一点消失。）

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Three-point perspective:

（3点透视）
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Three-point perspective is usually used for buildings seen from above (or below). In addition to the two vanishing points from before, one for each wall, there is now one for how those walls recede into the ground. This third vanishing point will be below the ground. Looking up at a tall building is another common example of the third vanishing point. This time the third vanishing point is high in space.
（三点透视通常被用于仰视或俯视建筑物。它在之前的两个灭点的基础上添加了一点，对于之前的方盒子而言，这一点是两个垂直面共有的消失点。第三个灭点在地平面之下（俯视）。高楼是另一个有第三个灭点的普遍例子，这时第三点位于高空中（仰视）。）
Part 1: Preparing the Background image in Photoshop:

（第一部分：在PS中准备背景图片。）
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For this tutorial I am going to demonstrate the process on a simple 1 point perspective image so that it is easier for first timers to follow but generally the rules apply to all forms of perspective.

（在这个教程中，我将示范如何处理一个简单的一点透视图片。这对初学者来说应该比较容易掌握，但基本的原则是可以被用在任何形式的透视中的。）

Fig 1: The background image used


First of all create a new file in Photoshop, the size isn’t too important (I have a 2000x2000 template that I use whenever I need to).
（首先在PS里创建一个新的文件，图片大小并不重要。（我有一个2000×2000的模版文件，这样我可以随时调用。）

Then create 3 horizontal guide lines (top, dead centre, and bottom), and Shift drag your background image into the Photoshop file so that it sits dead centre. PVZEB  
（然后创建三条水平参考线（顶部，中部和底部），并在PS中移动你的背景图片，直到它位于正中心。）

Fig 2: The set-up file with guides

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Drag your top and bottom guide lines so that they snap to the top and bottom of your image (as shows in fig 3a & b).

（拖动你的顶部和底部的参考线，直到他们吸附在图片的顶部和底部。）

Fig 3a & b: Adjusting the guides and image
（调整参考线和图片）



Now you need to shift and drag your back ground image up or down so that the horizon/eye level runs along the centre guide line.
（现在你需要上下拖动你的背景图片，直到图片中的地平线与中间的参考线重合。）


Readjust the top and bottom guidelines so that they are once again snap to the top and bottom of the background image.


（重新调整顶部和底部的参考线，直到它们再一次吸附到背景图片的顶端和底端。）

Using the select tool select the region between the top and middle guide (note if you needed to move your image down you would need to select the region between the middle and bottom guides) and move the selection (select > transform selection] to the opposite side of the middle guide.

（使用选择工具选中顶部和中部参考线之间的区域（注意：如果你需要把你的图片向下移，你就要选中中部和底部参考线之间的区域），然后移动选择框（选择》移动选择）到中间参考线的另一边。）
Fig 4: Transforming the selection （移动选择区域）

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Once again adjust the top or bottom guide to snap to the edge of the selection that is furthest away from the middle guide.
（再次调整顶部和底部参考线的位置，使之吸附到选择区域的边缘）
The Photo now has the horizon/eye level set right in the middle of the image. （现在照片的水平线处于图片的正中间了）
Finally all that is left to do in Photoshop is to crop the whole image to the top and bottom guides and the edges of the photo. It is also worthwhile typing in the image dimensions somewhere on the image for later reference. And save the file. （最后沿着顶部和底部参考线裁剪照片。为了方便之后的参考工作，请记下图片的大小，然后保存文件。）

Fig 5: Cropping the image to size (with image size in bottom corner)
（按照图片右下角的尺寸裁剪图片大小。）

Part 2: setting up the scene :  
（第二部分：设置场景）


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Now comes the straight forward bit, open up a new scene and create a “Target Camera” and position it at 0,0,0 so that it is dead centre of the 3D space
（现在可以很顺利的做下去了，在3dsmax中新建一个场景，创建一个目标摄影机，位置在0,0,0，也就是三维空间的最中心。）


Open up the viewport configuration window (Alt+B) and set the “Background Source File” to your newly saved image and use the settings shown.

（打开视窗配置窗口（ALT+B），设置你之前保存的图片为背景源文件，并按下图设置相关参数。）

Fig 6-7: Viewport and render settings （视窗和渲染设置）

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Open the render settings window (F10) and set the output size of the render to the same size as your background image (remember you typed the image dimensions on to your image for reference).
（打开渲染设置窗口（F10），将渲染输出的大小设置的和你的背景图一样大（还记得之前记下的图片大小吗？）

And select “Show safe frame” from the viewport drop down menu.  
（从视窗的下拉菜单中选择“显示安全框”）



And that’s it your background image and scene is all set so that the camera is the same height as the camera was when the photo was taken and is now ready for use, simply import your model/models into the scene and move into position
（现在背景和场景已经设置完毕，这样三维的摄像机已经和图片拍摄时候的相机一样高了，准备工作完成。简单导入一个模型到场景中，移动它的位置。）
You don’t need to move/adjust the camera, as that is set up as already. The only things you may need to adjust is the vertical positioning of the cameras target (for cases where you have a 3 point perspective) or the positioning of the model itself into the correct place.

（你不需要移动或调整摄像机，那个已经设置好了。现在惟一要调整的是摄像机目标点的垂直位置（例如背景是三点透视）以及模型本身的位置是否是在合适的地方。）

Fig 9-11: a simple box in the 3d max scene rendered with a matte shadow plane underneath, any object/scene can be easily imported in and will be aligned to the background 4
（图9－图11：3dsmax中渲染的一个简单的方盒子模型。现在任何物体都能轻易的导入场景匹配背景了。）



Fig.9

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Fig.10



Fig.11
来源：译文3D网