Cliff Retreat Moments: Part 2: Material ID and Masks

在Part 1中，我讨论了一些关于崖居别墅设计的研究片断。而在Part 2中，我将继续深入阐述我如何使用材质ID渲染通道来提高我选取材质的速度，并快速创建这些图片。这种方法不仅使我PS工作流程变得合理，而且如果设计发生改变，我也能方便快捷地对我的PS图层文件进行编辑。通过使用材质ID通道并对进行分组，每次我改变了我的设计，我可以很简单地渲染出一个新的ID材质通道，更新PS中的材质ID通道图层，并根据需要通过蒙版在PS中编辑替换某一区域的材质。下面简要介绍了我的方法:

In part one, I discussed some quick study vignettes of the cliff retreat design. For part two, I want to go into more depth about how I used a Material ID render channel to speed up my material selections and generate these illustrations in a relatively short amount of time. This not only streamlines my Photoshop workflow, but also allows me to make quick updates to my Photoshop files later if my design changes. By utilizing Material ID channels and masked groups, I can simply render out a new ID every time I make a change to my design, update the ID layer in my Photoshop file, and then use that new ID to update my masks as needed. Below is a quick explanation of how I do that.


1. TURN ON MATERIAL ID CHANNEL/打开材质ID通道

在这个教程中，我使用了SU V-Ray，它可以自动为模型中的不同材质生成不同颜色。以上就是我使用了材质ID通道的效果。大多数的渲染软件如V-Ray都提供了创建材质ID通道的功能。

In this tutorial, I am using V-Ray for Sketchup which automatically generates colors for each texture used in the model. Above is the what the Material ID channel looked like for my view. Most rendering programs like V-Ray offer the ability to create a Material ID channel.

要想启动材质ID通道的话，打开V-Ray编辑选项对话窗口，点击VFB Channels选项，在这个选项中找到位于“Standard Channels”列表的“Material ID”并选择它。当它被选择后，当你开始渲染图片时，V-Ray会为你生成以上的材质通道。

To turn on the Material ID channel, open the V-Ray Option Editor dialogue box, and go to the “VFB Channels” tab. In that tab, find “Material ID” in the Standard Channels list and select it. Now that it is selected, V-Ray will generate this channel when you render the image.


2. SAVE MATERIAL ID CHANNEL/保存材质ID通道

视图渲染完成后，在下拉菜单的左上角窗框处找到材质ID通道。选择它，你可以通过如下方法在渲染缓存窗中保存通道，但我一般都在“Output”选项中勾选“Save Output”小窗口，V-Ray会自动保存我所有的ID通道。

After rendering the view, you can find the Material ID channel in the upper left side of the frame buffer window in the drop down menu. You can save the image from the frame buffer window but I typically have V-Ray save all of my channels automatically by checking the “Save Output” box in the “Output” tab of the V-Ray Option Editor.


3. BRING IN MATERIAL ID CHANNEL INTO PHOTOSHOP/把材质ID通道导入PS

我喜欢把材质ID图层放在图层面板最上层。这样我可以随时简单地把它关闭而不受到其它图层的影响。

I like to keep my Material ID layer at the top of the layers palette. This allows me to turn it off and on easily to make selections without any other layers getting in the way.


4. MAKE SELECTION/创建选区

要建立材质ID选区的话，把材质ID图层打开，然后点击菜单栏中的“选择>色彩范围”。

To make a selection, select and turn on the Material ID Layer.  Then, Choose “Select>Color Range”.

当色彩范围对话框出现的时候，设置“模糊性”滚动条到大约50。这可能需要做一些调整，具体由被选择的颜色和细节决定。接下来，选择你要的颜色点击“OK”即可。

When the Color Range dialogue box appears, set the “Fuzziness” slider to somewhere around 50. This may need to be adjusted depending on the color and amount of detail that is being selected.  Next, pick the color that you want selected and then choose “OK”.


5. SETUP GROUP AND MASK/建组并创建蒙版

到这里我本可以就此结束这一期讲座，因为我们已经完成了用材质ID来创建一个选区，但我还想再进一步，在选区的基础上建立图层组蒙版。这样我们可以一次对所有相同材质图层的组建立蒙版，而不是对每个图层应用相同的蒙版。首先，点击位于图层面板下方的“创建新组”图标，建立一个新组。通过材质ID图层建立某一选区，点击同样位于图层面板下方的“创建蒙版”，对新组创建蒙版。

I could end this tutorial here since we have completed the task of using the Material ID to make a selection, but I want take it one step further and turn that selection into a mask on a group. This allows me to use one mask for many textures instead of applying the same mask to each individual layer.  First, create a new group by clicking the “Create a New Group” icon at the bottom of the layers palette. With the selection from the material ID still active, select the “Create New Mask” icon at the bottom of the layers palette. This will apply a mask to the group just created.

我现在把表示绿草材质拖进刚建立的新组，而不需要对每个草图层建立蒙版，材质自动被抠出来了。当我对栏杆或者墙体进行更改的时候，这样做极其有效，我不需要改变每个图层的蒙版，只需要更改图层组的蒙版。

通过渲染材质ID，我每张效果图的选取处理都异常快速精确。而通过对图层组建立蒙版，我一直以来都用很少的蒙版保持着一个清晰明了的PS图层工作面板。这样的工作流程使我能便捷地更新我的PS图层文件，从而更深入设计完善我的方案。

I now can drag my grass textures into that group just created and not have to worry about masking each individual grass texture. This is especially useful if I make changes to the railing or wall, I don’t need to update all of the individual grass texture masks. Instead, I only need to update the group mask and all of my grass textures inside will be updated too.
By rendering out the Material ID with each new rendering, I can make selection fast and accurately. By applying masks to groups instead of each individual layer, I  maintain a clean and organized Photoshop file with minimal masks. This workflow allows me to easily update my Photoshop files as I continue to design and refine my project.


出处：本文译自visualizingarchitecture.com/，转载请注明出处。