埃姆斯系列椅子关于材质的讨论

埃姆斯系列椅子关于材质的讨论
翻译by:yipinsucai.com

As promised, I wanted to follow up on my Eames series with a few  pointers about the materials created for the chairs. This is the first  in a series of mini how-to tuts about materials.
正如所承诺的,我想讨论一下我的埃姆斯系列的椅子关于创建椅子的材质。这是第一个系列迷你教程关于材质。
The Eames chairs are a good place to start. They all use materials  that are meant to show some age, a certain vintage quality and patina,  yet are as simple as materials can get. They are a good way to  demonstrate how materials can be made to look realistic without  necessarily using complex, multi-layered setups that would take a long  time to render. I will explore more complex materials later on (indeed,  I’m planning a post just about multi-layered mats), but, for the sake of  economy, I only use them in my work to achieve effects that cannot be  obtained with single-layer mats.
埃姆斯的椅子是一个很好的开端。它们使用的材料展示它们的年代,一定年份和光泽度,然却而很简单,比如做出材质。下面是一个很好的方法来演示材质可以看做的真实而且没有必要使用复杂的、多层的设置,需要很长时间来渲染。我以后将探索更复杂的材质(实际上,我计划写一个帖子关于多层材质),但是为了经济效益,我只有在工作中用单层材质达不到的效果的时候才使用多层材质。
For this series, I have cobbled together a material test scene. I may  upload it for free to TS if there is interest, but there really is  nothing to it. For illumination, it uses an HDR map and two light planes  (left and above). HDRIs in material testing scenes are anathema to  purists because they give the mats a non-neutral colour cast. I don’t  care. I want my materials to look the way they would in a fully  constructed scene and an HDRI map is the most efficient way to recreate a  plausible physical environment for the ball to to reflect and refract.  In any case, I would trust such a material scene vastly more than I  would the mat editor’s preview, which has a way of looking very much  unlike what the mat will look like in the scene.
对于本系列中,我已经拼凑一个材质测试场景。我可以免费上传它如果你有兴趣,但它确实是没有什么特别。对于照明,使用一个HDR贴图和两个面光(左边和上边)。HDRIs在材料测试场景里并不受欢迎,因为他们给材质球一个非中性的偏色。我不在乎。我想要我的材质看起来他们在造好一个场景里,一个HDRI贴图,最有效的作用是重新创建一个可信的物理环境的球,以反映和折射。在任何情况下,我会更相信这样一个实体场景大大超过在材质编辑器的预览,看上去更像现实中的效果。
A few points before looking at the specific mats.
观察一些特殊材质之前的要点。
1. Material creation should always be done by using real-world  reference. Try to look at the actual objects whose features you are  trying to re-create, or at least look at several photos taken in  different light conditions. Do not create materials just from memory or  by looking at other artists’ renders. Also, do not hesitate to ask  colleagues, partners or your kids about what they think of your  materials – a fresh pair of eyes, possibly belonging to someone who has  little to do with CG, is the best way to tell you if you are on the  right track.
1。材质创作总是应该通过使用真实世界的参考。尝试看看实际的对象特性你正试图重建的,或者至少看看几个在不同光照条件下拍摄的照片。不要创建材料只是从记忆中或通过查看其他艺术家的渲染。同样地,不要犹豫地问同事、合作伙伴或你的孩子们谈论那些他们认为的材料——一双明亮的眼睛,可能属于那些很少做CG的人,这是最好的方式,他们告诉你是否你在正确的轨道上。
2. Be as subtle as you can be. When fine-tuning a specular or bump  map, find a setting you like, then take the effect down one or two  notches. Some things should only be suggested.
2。尽量的敏感。当微调高光或凹凸贴图时,找一个你喜欢的设置,然后把效果下调一个或两个级别。有些事情只能建议。
3. Do not feel like you have to use variations of the same map in all  your slots. Real life does not always work like that (although it  sometime does). Add extra, discrete layers to your glossiness and bump  maps – they will only add to the material’s realism.
3。不要觉得你必须使用不同的贴图在你所有的材质槽。现实生活并不总是那样(尽管有时候是这样)。添加额外的,离散层到你的光泽度和凹凸贴图——他们会增加材料的真实感。
4. Even when doing single-layer materials, don’t be afraid of  layering your maps by using Max’s composite map or Vray’s blended  textures. These multilayered maps are a good way of masking repetitions  in tiled bitmaps and can help you conserve memory by deriving many  different looks from a limited number of maps.
4。即使做单层材料,不要害怕在你的贴图上的使用Max的复合贴图或Vray的混合材质。这些多层贴图是一种很好的方式来掩蔽重复的平铺的贴图,可以帮助你节省内存因为你省去了使用大量不同的贴图。
Eames plastic red
埃姆斯红塑料

This is one of the simplest materials in the scene, used on the  plastic version of the chair shells (for reference, the ball is  40x40cm). Here is how it looks like in Slate, including a few details  about the diffuse slot:
这是一个最简单的材料在场景里,用于塑料版本的椅子壳(作为参考,球是40 x40cm)。下面是它在材质编辑器里看起来的样子：

翻译by:yipinsucai.com
I could have used a plain colour here, or a VrayColor if I needed  float values. The reason I used a bitmap instead was that I wanted to be  able to easily switch the colour of the chair to one of a few  pre-determined hues. So I painted a small colour swatch in Photoshop  showing all the available tints for these chair models and used the  CroppingPlacement took in the bitmap editor in Max to isolate only one  colour – in this particular case a slightly orangey red.
我可以用一个纯色在这里,或一个VrayColor如果我需要float values。我之所以使用一个位图,是因为我希望能够方便地切换椅子的颜色为预先确定的色调。所以我画了一个小小的彩色样本在Photoshop中显示所有可用的色调为这些椅子模型，使用max裁切位图的功能选择一个颜色——在这个范例里是稍微橘红色。
The next step was to add a very subtle imperfection to the surface. I  didn’t want it to be visible in the diffuse, only in the specular and  glossiness slots, which is enough to give a slightly aged, real-world  feel to the material. Here is a low-res version of the map I used in the  specular slot (note that I only used unfiltered bitmaps, regardless of  the slot, even though that can lead to longer render times):
下一步是添加一个非常微妙的不完美的表面。我不希望它在表面上是可见的,只在高光和光泽度通道里,这足以给它一些年代感,感觉真实的材料。这里有一张低分辨率的版本的贴图我用于高光通道(注意,我只使用未经过滤的位图,无论哪个通道,尽管这可能导致更长的渲染时间):

You see that I used a much lighter, low-contrast version of the same  map in the glossiness map. That’s what you want to do, but you don’t  have to do it that way. Most of the time, you can get along by using a  colour-correct map to extract a lighter, lower-contrast version of the  spec map, which you can then plug into the glossiness slot.
你看,我用一种更亮的低对比度版本相同的贴图在光泽度通道里。这是你要做的,但是你不需要这样做。大多数时候,你可以通过使用一个颜色矫正贴图来提取一个亮的、低对比度版的贴图,然后可以塞进光泽度通道。
Lastly, I opted for a procedural noise map to replicate the rugged,  high-frequency bump on the plastic shell. Here is the setup (note the  very low scale):
最后,我选择了一个程序上的噪波贴图模拟崎岖、高频凹凸在塑料外壳上的效果。这是设置(注意非常低的缩放):

Here are the details about the material proper. I’ve marked in red  the important bits. These include Fresnel reflection on – as it should  be for all materials except very reflective metals; Reflection subdivs  of 64 – which can be lowered depending on your render settings;  reflection cut-off value of 0,001 (instead of the default 0,01), which  will ensure accurate reflections when working in linear space; specular,  glossiness and bump map contributions of 40, 55 and 18 per cent  respectively – essentially a way to fine-tune how heavily the map will  affect the final result.
这里有详细的材质参数。我用红色标注重要部分。这些包括菲涅耳反射——因为它应该对所有的材料除了非常反射金属都有用，反射细分64——这可以降低取决于你的渲染设置;反射截止值0.001(而不是默认的0,01),这将确保准确的反射当工作在线性空间，高光,光泽度和凹凸贴图的值分别为18%和40 55 -本质上调整贴图会影响最终结果。

Here is what the material looks like on a real model:
这是材质在模型里的效果：

And here is how it looks in black, which tells us one important thing – darker materials look more reflective:
这是它用黑色时看起来的效果,这告诉我们一个重要的事情——黑色材料看起来更反射:

Fibreglass
玻璃纤维

This material (designed for the vintage version of the chair as  environmentally-unfriendly fibreglass was originally used before it  became technically possible to cast entire plasic shells in one go) was  derived from the plastic material with the following tweaks:
这种材料(复古版的椅子那种材料，生产时用塑料把整个椅子的塑料壳完整地浇注出来)由塑料材质加上下面的调整:
1. A dirtier diffuse made by merging the colour bitmap with a dirt  map using a composite map set to a “multiply” blending mode at 75 per  cent;
1.一个脏表面由composite map融合表面色和污垢贴图设置为 “multiply”混合模式为75%;
2. A lower glossiness for sharper reflection and a slightly higher specularity;
2.较低的光泽度为尖锐的反射和一个略高的高光。
3. A “fibreglass” bump map – actually a normal map derived from  photos of real vintage chair shells (I only used the fibreglass map in  the bump slot because it was too repetitive to be used in the diffuse  slot, which I should ideally have done). There are many different  Photoshop plugins and standalone applications to derive normal maps from  photos. One cost-effective but bare-bone standalone solution is Shadermap. Another, costlier but integrated in Photoshop and endowed with more controls isPixplant.  Note that normal maps should be loaded as bitmaps with a gamma of 1.0  and plugged into a Normalbump or VrayNormal maps before being plugged  into the bump slot of the material.
3.一个“玻璃纤维“凹凸贴图,实际上是一个法线贴图来自真正的老古董椅子壳的照片(我只使用了玻璃纤维贴图在凹凸通道,因为它看起来太重复了如果使用在漫射通道)。有许多不同的Photoshop插件和独立应用程序获得法线贴图从照片上。一个性价比比较高的解决方案是Shadermap。另一个昂贵但集成在Photoshop和赋予更多的控制是Pixplant。注意,法线贴图应该加载在伽马1.0的环境里，并且要使用Normalbump或VrayNormal贴图在插入凹凸通道之前。
4. The dirt, specular and glossiness maps are the same that were used in the plastic material.
4.污垢,高光和高光模糊贴图都是相同的和之前用于塑料的材质。
Here is how the material looks like in slate:
下面是在slate材质编辑器里的思路：
翻译by:yipinsucai.com

And in the editor:
普通材质编辑器：

Sharp and painted metals
锐利的油漆金属


This example shows how minimal changes can yield completely different  looking materials. The main difference between these two is the absence  of fresnel reflection (for the chrome mat) and a dedicated bump map  (for the black paint mat). Otherwise, they share most of their  characteristics, as you can see here:
这个例子展示了如何可以产生少量更改制作看上去完全不同的材料。主要的区别这两个是菲涅耳反射率铬合金材质)和一个专用的凹凸贴图(黑漆垫)。其他的他们分享他们大部分的特性,你可以在这里看到的:

This is the kind of material that succeeds or fails based on the quality of the textures. I used three here:
这是属于一种材料：成功或失败基于纹理的质量。我在这里使用了三个纹理:
1. A specular map designed to give a very, very subtle variation in reflectivity across the surface;
1.一个高光贴图给了一个非常微妙的变化在表面反射率上;
2. a glossiness map, basically scratches, finger- and handprints painted with custom brushes in Photoshop;
2。一个光泽度贴图,表现划痕,手指或手掌碰触的效果，使用PS自定义笔刷制作的;
3. a bump map to “break” the surface of the painted material (note  how the bright spots on the map read like the grains of sand or dust you  often see on shoddy paint jobs).
3.一个凹凸贴图,“打破”表面油漆的材料(注意在贴图上的亮点,看上去就像沙粒和尘埃你经常看到在劣质油漆工作上看到的)。

Here are the two materials in the editor. Note that I’m using a Ward  this time, which works better for metals. Also, you will notice that the  contribution of the glossiness map is extremely low – you really want  this to be very subtle. If you cannot make it subtle enough, try loading  the bitmap with a gamma of one, which will make it even fainter.
这里有两种材质在编辑器中。注意,我使用一个Ward材质,这对金属效果更好。同时,您将注意到光泽度贴图给的数值极低——我真的希望贴图的效果是非常微妙的。如果你不能让它足够细微,尝试加载位图用伽马,这将使它更加微弱。


Old, tired metal
老旧的金属

I needed an older metal for my vintage chairs. This one was totally  over-the-top, but I quite liked the effect in the end so I decided to  include it here, just as an example of the interesting effects you can  obtain with single-layered materials and the right bitmaps.
我需要一个老旧的金属为我的老式椅子。这一个是完全言过其实的效果,但是我很喜欢最后的效果,所以我决定把它在这里作为一个例子,您可以获得有趣的效果只是用单层材质和正确的贴图。
Here are the details:
这是详细参数：


A few things to note:
一些注意点：
1. Fresnel reflection is not active, yet the reflectivity of the  metal is low, giving it a dustier look. The map only contributes 15 per  cent of specularity, with the specularity colour contributing the rest.  Mixing bitmaps and colours to generate the overall reflectivity will  make the effect more subtle.
1。菲涅耳反射是不开启的,然而,反射率给的低,给它一个尘封的效果。高光贴图图只给了15%，,高光的颜色贡献其余的反射率（颜色控制反射率）。混合位图和颜色来生成整个反射率会使效果更微妙。
2. The diffuse map was desaturated via a colour-correction map before use.
2。漫射贴图是通过颜色校正降低饱和度制作的。
3. The specular/glossiness maps are the same and, like the normal map, were derived from an inverted greyscale version of the diffuse (the white scratches had to be indented and unreflective, not prominent and reflective).
3。高光/光泽度贴图都是相同的,并且像法线贴图一样,来自一个反向的灰度版本的表面贴图(白色的划痕必须凹进去并且不反射的,而不是突出和反射的)。
Here is the maps I used:
这是我使用的贴图：

That’s it for today. I hope this was of some interest. I’ll be back  shortly with a look at more complex materials. Of course, feel free to  ask if you would like to know about a specific material or effect.
今天到此为止。我希望这是有些意思。我很快就会回来研究更复杂的材质。当然,随时问如果你想知道一个特定的材料或效果。
翻译by:yipinsucai.com