3D靜物 - 分解

我最近完成了我的靜物畫(huà)面，所以決定快速分解現(xiàn)場(chǎng)發(fā)生的情況！ 我將整個(gè)管道，從拍攝的背板和捕捉照明信息通過(guò)各種方式合成。

I recently finished my still life image, so decided to do a quick breakdown of what's going on in the scene! I will go over the whole pipeline, from shooting the backplate and capturing the lighting information all the way through to compositing.

Shooting the backplate and capturing the lighting information

After I knew what I was going to do, it was time to shoot backplate and capture all the lighting information.

For this I used:

- Canon 5D Mark II

- 50mm 1.4f

- 8mm 3.5f fisheye

- Tripod with a panoramic head (One that clicks every # of degrees. Very useful when creating HDRs)

- Chrome & grey sphere (to check my lighting)

- Macbeth chart (to calibrate my colors)

The first thing I did was to try and make a composition that was less or more pleasing to the eye in real life, maybe trying to get some happy accidents in that occur MUCH more often in real life than in 3D. I also used it as my main big reference to shade objects. All in all, this is a very useful thing to do even if you're not using any of it in your 3D scene.

拍攝背板并捕捉照明信息

在我知道我要做什么之后，現(xiàn)在是拍攝背板并捕獲所有照明信息的時(shí)候了。

為此我用：

- 佳能5D Mark II

- 50mm 1.4f

- 8mm 3.5f魚(yú)眼

- 三腳架全景頭（一個(gè)點(diǎn)擊每個(gè)度數(shù)，創(chuàng)建HDR時(shí)非常有用）

- Chrome和灰色球體（以檢查我的照明）

- 麥克白圖（校準(zhǔn)我的顏色）

我做的第一件事就是試著做一個(gè)在現(xiàn)實(shí)生活中看起來(lái)不那么喜歡的作品，也許試圖在現(xiàn)實(shí)生活中比在3D中更多地發(fā)生更多的事故。 我也用它作為我主要的重要參考。 總而言之，即使在3D場(chǎng)景中沒(méi)有使用任何東西，這也是非常有用的。

Shooting the backplate was very straightforward. I shot: a clean one, one with lighting checkers and one with a color checker. Something to note is that your camera has to be on manual mode. You do not want to have different settings for each of these shots. They all need to match!

Also ALWAYS shoot in RAW for these kinds of things. You don't want to have a compressed .jpg before you've even started.

The following pictures are shot in a really bright sunny environment, even though they don't really look like it. They're just as raw as it comes out of my camera sensor, and need some grading work to make them pretty again.

拍攝背板非常簡(jiǎn)單。 我拍攝的時(shí)候：一個(gè)干凈的背景，一個(gè)照明檢查器和一個(gè)與顏色檢查器。 需要注意的是，您的相機(jī)必須處于手動(dòng)模式。 您不想為每張照片都設(shè)置不同的設(shè)置。 他們都需要匹配！

還要一直在RAW拍攝這些類型的東西。 在你開(kāi)始之前，你不想要壓縮.jpg。

以下圖片在真正晴朗的陽(yáng)光環(huán)境中拍攝，即使它們看起來(lái)不是很像。 它們是從我的相機(jī)傳感器出來(lái)的原始，并需要一些分級(jí)的工作，使他們?cè)俅纹�亮�?/p>

These days I try to use Nuke as much as possible, steering away from Photoshop as much as I can. This gave me a problem ? by default Nuke doesn't read Canon's .cr2 raw files. I turned to DCRAW, an open source piece of software that you can access from the command line once installed. It reads ALL raw formats and converts it the input into a 16bit tiff.

Later on I learned that also NUKE can use DCRAWs code. Just put the DCRAW files into your nuke directory in your home folder, and enjoy reading in .cr2 files in Nuke! You even get an argument line in your read node where you can enter your options for DCRAW. Super sweet!

這幾天我盡可能多地使用Nuke，盡可能多地轉(zhuǎn)向Photoshop。 這給了我一個(gè)問(wèn)題？ 默認(rèn)情況下，Nuke不會(huì)讀取佳能的.cr2原始文件。 我轉(zhuǎn)向DCRAW，一個(gè)開(kāi)源的軟件，您可以在安裝完成后從命令行訪問(wèn)。 它讀取所有原始格式，并將其轉(zhuǎn)換為16位tiff。

后來(lái)我了解到NUKE也可以使用DCRAWs代碼。 只需將DCRAW文件放入您的home文件夾中的nuke目錄，并享受Nuke中的.cr2文件的閱讀！ 您甚至可以在讀取節(jié)點(diǎn)中獲得一個(gè)參數(shù)，您可以在其中輸入DCRAW的選項(xiàng)。 超棒！

Shooting the HDR

Once the backplate had been shot, it was time to capture the lighting information in the room. This is most commonly done by using a fisheye lens (because of the extreme wide angle), and shooting at least three exposures for every angle, for the full 360 degrees. You can shoot every 120, 90, and 60 ? it's entirely up to you! Just keep in mind that you do not want your lighting to change or your objects to move during the shoot. I personally went for 6 angles because I was the only one in the room and there were no clouds. Probably as easy as shooting an HDR gets!

Once again, I made sure my camera was set as manual as possible. I even chose a white balance setting just to be consistent across all my images, even though it makes absolutely no difference for raw images.

Using the panoramic head of my tripod, I shot three exposures (called exposure bracketing) for every angle. I did this using a little two second timer. Three Exposures really is the bare minimum, you should shoot more if you can. The camera I used with the default OS just can't do more than three.

I placed my Macbeth chart within a sunny area of my environment, so I can color calibrate the HDR to my photographed backplate (explained later on).

After the shoot I ended up with 18 .cr2 images. I stitched them together with an incredibly neat piece of software called PTGui.

PTGui outputted me the following 32bit EXR. Great ? but not there yet. The highest floating point value within the image was only 4 (keep in mind that 8 bit images can only store values between 0 and 1). I used a Nuke gizmo called mmColorTarget to match the values of the Macbeth chart in the HDR to the values of the Macbeth chart in my backplate (read more about this on the renderblog), and this boosted my max floating point value up to about 240.

拍攝HDR

一旦背板被拍攝，現(xiàn)在是捕捉房間內(nèi)照明信息的時(shí)候了。這通常是通過(guò)使用魚(yú)眼鏡頭（因?yàn)闃O寬的角度）而完成的，并且對(duì)于整個(gè)360度，對(duì)于每個(gè)角度拍攝至少三次曝光。你可以每120度，90度和60度拍攝，這完全取決于你！請(qǐng)記住，在拍攝期間，您不希望照明更改或您的物體移動(dòng)。我個(gè)人用了6個(gè)角度，因?yàn)槲沂俏ㄒ灰粋�(gè)在房間里，沒(méi)有云�？赡芟衽臄zHDR一樣容易！

再次，我確保我的相機(jī)設(shè)置為盡可能的手動(dòng)。我甚至選擇了一個(gè)白平衡設(shè)置，使其在所有圖像上保持一致，即使原始圖像絕對(duì)沒(méi)有區(qū)別。

使用三腳架的全景頭，我為每個(gè)角度拍攝了三次曝光（稱為曝光包圍）。我這樣做了兩秒鐘的定時(shí)器。三個(gè)曝光真的是最低的，你應(yīng)該可以拍攝更多，如果可以的話。與默認(rèn)操作系統(tǒng)一起使用的相機(jī)不能超過(guò)三個(gè)。

我把我的Macbeth圖表放在我環(huán)境晴朗的地方，所以我可以將HDR彩色校準(zhǔn)到我拍攝的背板（稍后解釋）。

拍攝結(jié)束后，我結(jié)束了18 .cr2的圖像。我把它們拼湊成一個(gè)非常整潔的軟件PTGui。

PTGui輸出了以下32bit EXR。好嗎但還沒(méi)有。圖像中最高的浮點(diǎn)值僅為4（請(qǐng)記住，8位圖像只能存儲(chǔ)0到1之間的值）。我使用一個(gè)名為mmColorTarget的Nuke gizmo將HDR中的Macbeth圖表的值與我的背板中的Macbeth圖表的值相匹配（在renderblog上更多地了解這一點(diǎn)），并將我的最大浮點(diǎn)值提高到大約240 。

A high value like this is great; it gives you nice crisp shadows. No need to fake this using CG lights! After the calibration, I color graded it a bit more for artistic purposes.

這樣高的價(jià)值是偉大的，它給你很好的陰影。 沒(méi)有必要用CG燈偽造這個(gè)！ 校準(zhǔn)后，為了藝術(shù)目的，我的顏色分?jǐn)?shù)更多。

Lens Distortion

So that's my HDR image sorted. Great! Just a couple more things and we can move into 3D space.

First thing I had to do is color grade my backplate a bit for artistic purposes. After that was done, I had to undistort the image. Real lenses always have their own lens distortion.

Undistorting this is easy because of the already available algorithms in Nuke. I just printed off this grid and snapped a picture of it at a 90angle, then read it in Nuke and used a lensDistortion node to analyze this grid, copy pasted the node and plugged it into my main node network. Easy! Ready to be used in 3D.

鏡頭失真

那就是我的HDR圖像排序。 大！ 只有幾件事情，我們可以進(jìn)入3D空間。

我必須做的第一件事是顏色等級(jí)我的背板有點(diǎn)為藝術(shù)目的。 在此之后，我不得不保留形象。 鏡頭總是有自己的鏡頭扭曲。

由于Nuke中已經(jīng)有可用的算法，因此，這是非常簡(jiǎn)單的。 我剛剛打印出這個(gè)網(wǎng)格，并以90度的角度拍攝照片，然后在Nuke中讀取它，并使用鏡頭分解節(jié)點(diǎn)分析此網(wǎng)格，復(fù)制粘貼節(jié)點(diǎn)并將其插入到我的主節(jié)點(diǎn)網(wǎng)絡(luò)中。 簡(jiǎn)單！ 準(zhǔn)備在3D中使用。

Aligning the camera to the scene

There are a couple of tricks to keep in mind when trying to align your camera in 3D. It can be a pain, but if you have taken the right steps, your image should line up perfectly.

A couple of tips:

- Measure your real life objects with precision, always make notes of measurements when shooting

- Make sure your image has no lens distortion

- If you shoot with a cropped sensor camera, make sure you multiply your cropping factor with your lenses focal length, and then enter that value into your Maya cam. Maya doesn't know whether you shoot with a cropped frame sensor or a full frame sensor!

And then there's a really useful trick that I learned from a senior modeler at MPC:

? Create your camera and immediately group it. On your camera, lock the rotation channels. On your group, lock the translation ones. By doing this you can select your group, pan around with your camera and adjust the rotation values very precisely using the rotate tool.

I feel like this trick really helps a lot when trying to precisely match something. You can also undo every camera movement really easily like this.

It will take a couple of minutes of thinking "this is never going to match up", but you will get there eventually.

將相機(jī)對(duì)準(zhǔn)場(chǎng)景

嘗試將相機(jī)與3D對(duì)齊時(shí)，請(qǐng)記住幾個(gè)技巧。如果你采取了正確的步驟，你的形象應(yīng)該完美排列。

幾個(gè)提示：

- 精確測(cè)量您的現(xiàn)實(shí)生活中的物體，拍攝時(shí)始終記錄測(cè)量結(jié)果

- 確保您的圖像沒(méi)有鏡頭變形

- 如果使用裁切的傳感器攝像頭拍攝，請(qǐng)確保將裁剪系數(shù)與鏡頭焦距相乘，然后將其輸入您的Maya凸輪。Maya不知道你是否用裁剪的幀傳感器或全幀傳感器拍攝

然后我從MPC的高級(jí)建模師那里學(xué)到了一個(gè)非常有用的技巧：

創(chuàng)建您的相機(jī)并立即分組。在相機(jī)上鎖定旋轉(zhuǎn)通道。在你的小組，鎖定翻譯。通過(guò)這樣做，您可以選擇您的組，使用相機(jī)平移，并使用旋轉(zhuǎn)工具非常精確地調(diào)整旋轉(zhuǎn)值。

我覺(jué)得這個(gè)伎倆真的幫助很多，當(dāng)試圖精確匹配的東西。您也可以輕松地撤消每個(gè)相機(jī)的移動(dòng)。

Setting up the scene

Wicked. So we've got all our photographic elements ready to go and our proxy geometry is modeled to match the objects in our photograph. Time to set up the scene.

We know that we will need both information from the HDR (direct illumination) and information from the environment (indirect illumination, because the light has already bounced once) to light our scene properly.

It's really easy to set this up in Arnold, but it did take me some initial figuring out.

I assigned a ShadowCatcher shader to all the modeled ?shadow catching' geometry. Since the geometry also has to cast shadows, do not disable ?opaque' in the Arnold tab ? unlike specified in the documentation.

設(shè)置場(chǎng)景

所以我們已經(jīng)準(zhǔn)備好了所有的攝影元素，我們的代理幾何是為了匹配照片中的對(duì)象。 設(shè)置場(chǎng)景的時(shí)間

我們知道，我們將需要HDR（直接照明）和環(huán)境信息（間接照明，因?yàn)楣庖呀?jīng)反彈一次）的信息，以適當(dāng)?shù)卣樟廖覀兊膱?chǎng)景。

在阿諾德這樣做很容易，但是它確實(shí)帶給我一些初步想法。

我分配了一個(gè)ShadowCatcher著色器到所有被建模的陰影捕捉幾何。 由于幾何也必須投射陰影，不要在Arnold選項(xiàng)卡中禁用，opaque， 與文檔中指定的不同。

The ShadowCatcher shader has some cool attributes. The first one we'll look at is the most important one. Use background.

In this slot we will pipe in a projection. In your node editor, just create a File [projection] node. It's pretty straightforward, plug in both your projection camera and image you want to project and make sure you have your UVs laid out for the objects you are projecting onto.

Important! Having it set up like this, your shadow catching geometry will also have a diffuse texture (the projection). This is NOT what we want, so we pipe the projection into an aiRaySwitch node, just not connecting the ?camera rays' slider. This will essentially not return any camera rays, whilst still returning all the other rays ? exactly what we want.

The rest is easy. Enable cast shadows, transparency and catch diffuse. Catch diffuse is one to play with ? it affects the colors of the shadows depending on the diffuse color. I wonder why I didn't try piping in the projection into that. Might be worth testing out!

ShadowCatcher著色器有一些很酷的屬性。我們要看的第一個(gè)是最重要的。使用背景。

在這個(gè)槽中，我們將投射一個(gè)投影。在您的節(jié)點(diǎn)編輯器中，只需創(chuàng)建一個(gè)File [投影]節(jié)點(diǎn)。這是非常簡(jiǎn)單的，插入投影相機(jī)和您想投影的圖像，并確保您的UVs布局為您投射的對(duì)象。

重要的！使其設(shè)置如此，您的陰影捕捉幾何也將具有漫反射紋理（投影）。這不是我們想要的，所以我們將投影管道放入aiRaySwitch節(jié)點(diǎn)，只是不連接相機(jī)射線的滑塊。這將基本上不會(huì)返回任何相機(jī)射線，同時(shí)仍然返回所有其他射線，正是我們想要的

其余的很容易啟用投射陰影，透明度和捕捉漫反射。捕捉彌漫它影響陰影的顏色取決于漫射顏色。我不知道為什么我沒(méi)有在投影中嘗試管道�？赡苤档脺y(cè)試！

For the lighting, I just created a skydome light with the HDR attached, intensity kept at 1. With the help of a chrome sphere I matched the direction of the light.

對(duì)于照明，我剛剛創(chuàng)建了一個(gè)與附加的HDR的滑雪燈，強(qiáng)度保持在1.在鉻球的幫助下，我匹配光的方向。

Modeling the objects

I really enjoyed the modeling aspect of this project. I usually do bigger things, which means I don't get to model into this fine detail. Really fun when there's no cap on your polycount and you can try and get every nice little shape in there! I only box modeled the tape, the tin and one single tube.

I laid out the UVs and after that I took the tubes into ZBrush and sculpted them an individual ZDisp map. I also quaded up the geometry so I'd get an even distribution of resolution whilst sculpting. It's always a good idea to do this!

Usually whilst sculpting this I'd reach for the DamStandard brush ? however, since it pinches the geometry and my UVs are already laid out, this is not ideal. I can't have the pinching. To work around this I simply took the alpha of the DamStandard brush and applied it to my regular Standard brush. Simple, problem solved. The whole time I watched closely that I was only working in the normal direction of the faces so not too much stretching would appear when they were textured.

A quick demonstration on how I approached sculpting the paint tubes can be seen here.

For both the paint tubes and the tin can I found that I also had to break up the surface with quite a bit of low level noise (which I sculpted, I did not do this procedurally). This really helped to sell the objects.

To create the paint splatters on the objects, I developed two ways ? and switched halfway through the project! The first one was to get some Photoshop splatter brushes, import those into MARI, splash them onto my object and convert that layer's alpha into a mask. This gave me a clean mask regardless of the color of the paint. Then I imported this map as an alpha into ZBrush and under the masking submenu I clicked ?Mask by Alpha?. The only thing I then had to do is inflate certain parts and sculpt a bit of texture on top.

Halfway through the project I found that it was much easier to have all this paint as separate geometry. It allows for much greater control rather than having it at render time through a Displacement map. I used the same splatter maps, but converted the ZBrush masks into polygroups. Then I could split off all the faces that weren't ?splatters', give it some thickness and DynaMesh that. It's pretty high res geo (although you generate the same amount of polygons with your disp map), but I found that it looks a lot better than having your actual object displaced.

The water droplets were created with the Waterdrop generator I made a while ago. It's free and it works fairly well, check it out here!

建模對(duì)象

我非常喜歡這個(gè)項(xiàng)目的建模方面。我通常做更大的事情，這意味著我不會(huì)模仿這個(gè)細(xì)節(jié)。真的很有趣，當(dāng)你的多數(shù)帳戶沒(méi)有上限，你可以嘗試，并獲得每一個(gè)美好??的小形狀在那里！我只用盒子塑造了磁帶，錫和一根單管。

我畫(huà)出了紫外線，之后我把管子插入ZBrush，并雕刻出一個(gè)ZDisp的地圖。我也加了幾何，所以我會(huì)得到一個(gè)均勻分辨率的雕刻。這樣做總是一個(gè)好主意！

通常雕刻時(shí)，我會(huì)使用DamStandard畫(huà)筆。然而，由于它夾著幾何體，我的紫外線已經(jīng)布局，這不是理想的。我不能捏捏為了解決這個(gè)問(wèn)題，我簡(jiǎn)單地拿了DamStandard筆刷的alpha，并把它應(yīng)用到我的普通標(biāo)準(zhǔn)畫(huà)筆上。簡(jiǎn)單，問(wèn)題解決。一直以來(lái)，我一直在密切注視著我只是在正常的方向上工作，所以在紋理化時(shí)不會(huì)出現(xiàn)太多的拉伸。

在這里可以看到一個(gè)關(guān)于如何接近雕刻油漆管的快速示范。

對(duì)于涂料管和錫罐，我可以發(fā)現(xiàn)我也不得不用相當(dāng)?shù)偷脑胍簦ㄎ业窨蹋�我沒(méi)有這樣做）分解表面。這真的有助于銷售物品。

要在對(duì)象上創(chuàng)建油漆飛濺，我開(kāi)發(fā)了兩種方法。并在項(xiàng)目中途切換！第一個(gè)是得到一些Photoshop飛濺畫(huà)筆，將其導(dǎo)入MARI，將它們?yōu)R到我的對(duì)象上，并將該層的Alpha轉(zhuǎn)換成掩碼。這給了我一個(gè)干凈的面具，無(wú)論顏色的顏色。然后我將這個(gè)地圖作為一個(gè)alpha導(dǎo)入到ZBrush中，然后在我點(diǎn)擊的掩碼子菜單下面。我唯一需要做的就是膨脹某些部分，并在上面雕刻一點(diǎn)紋理。

通過(guò)該項(xiàng)目的中途，我發(fā)現(xiàn)將所有這些油漆作為單獨(dú)的幾何體都容易得多。它允許更好的控制，而不是通過(guò)位移圖在渲染時(shí)使用它。我使用了相同的Splatter映射，但是將ZBrush掩碼轉(zhuǎn)換為polygroups。然后我可以把所有的面都分開(kāi)，沒(méi)有噴濺，給它一些厚度和DynaMesh。它是非常高的地理位置（雖然你生成相同數(shù)量的多邊形與您的disp映射），但我發(fā)現(xiàn)它看起來(lái)好比讓您的實(shí)際對(duì)象移位。

水滴是用我之前做過(guò)的水滴發(fā)生器創(chuàng)建的。它是免費(fèi)的，它的工作相當(dāng)不錯(cuò)，在這里查看！

Texturing

As always, I textured my objects in MARI. It was pretty easy ? nothing like texturing something that is supposed to look alive! The first step is probably the most important one, and that is looking for good reference. Once you know what you have to paint, and take the guesswork out, it's just doing it.

The labels of the objects were created in Photoshop since MARI lacks a lot of 2D tools. I then exported the maps and imported those into MARI, where I painted the Isolation maps of the layered shaders (more on this later on), splatters, a dirt layer and a dust layer.

The way I paint my isolation maps is simple. I just paint them with the standard MARI brushes, but not in black and white. If I'm painting dust, I need it to look like dust to be able to properly judge its appearance. So when I'm done with it, I just convert the layer's alpha into a mask. By doing this I can easily export the color map and the mask, to use in my layered shaders.

Note that you can also export the colored version, and use the alpha channel of that image to drive the mask properties of the layered shader. It's just whatever you prefer!

If I could recap one thing about texturing, it would be reference. Reference reference and more reference!

紋理

和往常一樣，我紋理我的對(duì)象在MARI。這很簡(jiǎn)單沒(méi)有什么像紋理的東西應(yīng)該看起來(lái)活著！第一步可能是最重要的，那是尋找好的參考。一旦你知道你要畫(huà)什么，并且想象出來(lái)，那就是這樣做。

對(duì)象的標(biāo)簽是在Photoshop中創(chuàng)建的，因?yàn)镸ARI缺少很多2D工具。然后我出口地圖并將其導(dǎo)入MARI，在那里我畫(huà)了分層著色器的隔離貼圖（稍后再介紹），噴濺，污垢層和灰塵層。

我畫(huà)我的隔離地圖的方式很簡(jiǎn)單。我只是用標(biāo)準(zhǔn)的MARI刷子涂抹它們，但不是黑色和白色。如果我在畫(huà)灰塵，我需要它看起來(lái)像灰塵能夠正確判斷它的外觀。所以當(dāng)我完成它，我只是將層的alpha轉(zhuǎn)換成一個(gè)掩碼。通過(guò)這樣做，我可以輕松導(dǎo)出顏色貼圖和掩碼，以便在我的分層著色器中使用。

請(qǐng)注意，您還可以導(dǎo)出彩色版本，并使用該圖像的alpha通道來(lái)驅(qū)動(dòng)分層著色器的蒙版屬性。這只是你喜歡的！

如果我可以回顧一下關(guān)于紋理的一點(diǎn)，那就是參考。參考參考和更多參考！

Shading

I received some requests to dive a bit deeper into the shading of the objects, so I will try to do this!

If you've read about my previous work, you've probably noticed I like to use the alShader library instead of the standard Arnold library. It has many advantages, which you can read about over here.

At this moment in time I really like to think about shading as like thinking in layers, and I also build the networks this way. It gets pretty easy when doing this. I will go over three objects, the coffee tin, the paint tube and the tape.

底紋

我收到一些請(qǐng)求，深入對(duì)象的陰影，所以我會(huì)盡力做到這一點(diǎn)！

如果您已經(jīng)閱讀過(guò)我以前的作品，您可能已經(jīng)注意到我喜歡使用alShader庫(kù)而不是標(biāo)準(zhǔn)的Arnold庫(kù)。 它有很多優(yōu)點(diǎn)，您可以在這里閱讀。

在這個(gè)時(shí)候，我真的很想像陰影一樣思考層層疊畫(huà)，我也以這種方式建立網(wǎng)絡(luò)。 這樣做很容易。 我會(huì)去三個(gè)物體，咖啡錫，油漆管和膠帶。

Coffee Tin

As I mentioned earlier, everything begins with good reference. Life is pretty once you know what you've got to do, reach or accomplish. Then it's just doing it! Before I start, I always try to push myself to spend that extra bit of time on the internet, looking for that one picture that might push my idea that little bit further.

咖啡渣

正如我前面提到的，一切都從好的參考開(kāi)始。 一旦你知道你要做什么，達(dá)到或完成，生活就會(huì)很好。 那就是這樣做！ 在我開(kāi)始之前，我總是試圖把自己花在互聯(lián)網(wǎng)上花費(fèi)更多的時(shí)間，尋找那個(gè)可能會(huì)推動(dòng)我的想法的圖片。

The first thing I do is inspect the object, and stare at it for a couple of minutes. How does the light react with the surfaces? What properties of the surface really leave a mark in my mind? Are there any noteworthy specialties? What are the material layers of this object?

For example, the coffee tin will have six main layers:

1. Base metal

2. The super thin tin coat over the metal

3. The label material

4. Paint layer

5. Dirt (wasn't needed for this asset in my image, but still worth noting that it is there!)

6. Dust (wasn't needed for this asset in my image, but still worth noting that it is there!)

Once we've got the layers figured out, it's playtime. All we have to do now is recreate them and paint masks to layer the shaders on top of each other.

我做的第一件事是檢查物體，盯著它幾分鐘。 光如何與表面反應(yīng)？ 表面的什么屬性真的在我心中留下痕跡？ 有什么值得注意的專業(yè)嗎？ 這個(gè)對(duì)象的材質(zhì)層是什么？

例如，咖啡錫將有六個(gè)主要層：

賤金屬

金屬上的超薄錫涂層

3.標(biāo)簽材料

4.油漆層

5.污垢（我的形象不需要這個(gè)資產(chǎn)，但還是值得注意的是它在那里�。�

灰塵（在我的形象中這個(gè)資產(chǎn)不是必需的，但還是值得注意的是它在那里�。�

一旦我們得到了這些圖層，就是播放時(shí)間。 我們現(xiàn)在要做的就是重新創(chuàng)建它們并繪制掩模，以使著色器彼此層疊。

The way I approach building the materials at the moment is still very much by eye. I would like to start using more scientifically correct values and numbers soon, it's something that I'm working on.

So, for now, eyeballing! Let's start with layer one ? the metal.

In real life you'd have two layers for the base metal. The actual base metal that the coffee tin is made from, and then a tin layer on top. Because the underlying metal layer really is barely visible (just through some scratches), and if it would be visible, it wouldn't have had any crazy visual impact. So instead of building it this way, I decided to just create a tin material and use a spec map to emulate that metal layer underneath.

Because it's a metal, the Diffuse color should be black. Ideally you'd pipe a really dark breakup map into this, nothing is perfect in real life, but it just wasn't necessary in this case.

The Specular map is a simple tiling map with some scratches. I add a bit of color to this spec map by multiplying the tiling map on top of a color (light beige ? metals have a colored Specular highlight!) through an alLayerColour node. No need to go and do this in another software package.

目前我正在構(gòu)建材料的方式還是非常有意義的。我想盡快開(kāi)始使用更科學(xué)正確的價(jià)值觀和數(shù)字，這是我正在努力的。

所以，現(xiàn)在眼球！我們從第一層開(kāi)始吧？金屬。

在現(xiàn)實(shí)生活中，你會(huì)有兩層賤金屬�？Х儒a制成的實(shí)際賤金屬，然后是頂部的錫層。因?yàn)榈讓拥慕饘賹诱娴膸缀蹩床坏剑ㄖ皇峭ㄟ^(guò)一些劃痕），如果它是可見(jiàn)的，它不會(huì)有任何瘋狂的視覺(jué)沖擊。所以我不是用這種方法來(lái)構(gòu)建一個(gè)錫材料，而是使用一個(gè)規(guī)格圖來(lái)模擬下面的金屬層。

因?yàn)樗�是一種金屬，彌漫顏色應(yīng)該是黑色的。理想情況下，您將管理一個(gè)真正黑暗的破碎地圖，在現(xiàn)實(shí)生活中沒(méi)有什么是完美的，但在這種情況下，這并不是必需的。

鏡面圖是一個(gè)簡(jiǎn)單的貼圖，有些劃痕。我通過(guò)一個(gè)alLayerColour節(jié)點(diǎn)乘以一個(gè)顏色（淺米色，金屬有一個(gè)彩色的鏡面高光�。┥系钠戒佡N圖，給這個(gè)規(guī)格圖添加了一點(diǎn)顏色。不需要去另一個(gè)軟件包去做。

As you can see I use the two specular lobes provided by the alSurface shader in here. As I said before, I'm not going to lie; I haven't got any real values for these. Right now I'm trying to match the reflection by looking at my reference very, very closely! What I'm creating here is a combination of both a rougher reflection, and a sharper one.

The IOR value is pumped up to 5 to have it reflect like a metal. You can use values up to 100 or even 1000 to get a chrome like Fresnel falloff.

That's that for the tin layer. Now let's create an alLayer shader, another alSurface shader for the label shader and a file node to connect the mask that we painted into the layered shader.

如您所見(jiàn)，我使用alsurface著色器提供的兩個(gè)鏡面波瓣在這里。正如我之前所說(shuō)，我不會(huì)撒謊我沒(méi)有任何真正的價(jià)值觀�，F(xiàn)在我試圖通過(guò)非常非常非常密切地查看我的參考來(lái)匹配反思。我在這里創(chuàng)造的是一個(gè)更粗糙的反思和更清晰的反射的組合。

IOR值被泵送到5以使其像金屬一樣反射。您可以使用高達(dá)100甚至1000的值來(lái)獲得像菲涅爾衰減的鍍鉻。

那就是錫層。現(xiàn)在讓我們創(chuàng)建一個(gè)alLayer著色器，另一個(gè)用于標(biāo)簽著色器的alSurface著色器和一個(gè)文件節(jié)點(diǎn)將我們繪制的蒙版連接到分層著色器中。

TOP TIP 1: By default if you drag and drop the file node onto the mask attribute, it will connect out alpha to the input. This is NOT what we want! Make sure you switch the out alpha connection of the file node to out color. Since we've painted a black and white mask, all individual color channels will be identical. Connect it to either the red channel, blue channel or green channel depending on your favorite color.

TOP TIP 1：默認(rèn)情況下，如果將文件節(jié)點(diǎn)拖放到掩碼屬性上，它將連接到輸入的alpha。這不是我們想要的！確保將文件節(jié)點(diǎn)的外部alpha連接切換到外部顏色。由于我們畫(huà)了一個(gè)黑色和白色的面具，所有單獨(dú)的顏色通道將是相同的。根據(jù)您最喜歡的顏色將其連接到紅色通道，藍(lán)色通道或綠色通道。

TOP TIP 2: You can also work with just one texture file with transparency. In that case, obviously don't change the connection

Cool, let's move onto the label shader. Not that much special going on here, but definitely an important layer to get right. It's the shader that will dominate the biggest area of the image. All I did was connect my diffuse map that I painted, and set my spec parameters as the following:

TOP TIP 2：您還可以使用一個(gè)透明的紋理文件。 在這種情況下，顯然不要改變連接

很酷，我們來(lái)看標(biāo)簽著色器。 這不是特別的，但絕對(duì)是一個(gè)重要的層面。 這是著色器，將主導(dǎo)圖像的最大區(qū)域。 我所做的是連接我繪制的漫反射圖，并設(shè)置我的spec參數(shù)如下：

Note that I used a slightly tinted Specular color. This is for artistic reasons ? it gave me a much ?fuller' feeling. It's hard to describe, but it worked. You should always remind yourself that you're an artist, not a scientist. It's good to base yourself on values that are proven to be correct, but there's no one saying you can't cheat if you know why you cheat.

The last layer for this object is the paint layer. Again, nothing special going on really! Just a diffuse color map and some tweaked spec values.

請(qǐng)注意，我使用了一個(gè)稍微有色的鏡面顏色。 這是出于藝術(shù)原因嗎？ 它給了我更多的感覺(jué)。 這很難描述，但它的工作。 你應(yīng)該總是提醒自己，你是一個(gè)藝術(shù)家，而不是科學(xué)家。 把自己置于證明是正確的價(jià)值觀上是很好的，但是沒(méi)有人說(shuō)如果你知道你為什么欺騙，你不能欺騙。

該對(duì)象的最后一層是涂層。 再次，沒(méi)有什么特別的事情真的！ 只是一個(gè)漫反射的顏色地圖和一些調(diào)整的spec值。

That's actually it for the tin can! Nothing special or over complicated, but still looks pretty sweet. Working in layers is easy!

這實(shí)際上是為了錫罐！ 沒(méi)有什么特別或過(guò)于復(fù)雜，但仍然看起來(lái)很甜蜜。 分層工作很容易！

Tape

The tape was fun to make; it's not something you shade every day! The main thing to note about this object is that I created two different shaders ? one for the actual roll of tape, which is double sided geometry, and one for the torn off tape ? which is single sided. This is an important feature to consider, because we have to shade single sided objects differently. For example, sub surface scattering effects that I would use on double sided geo don't make sense on single sided geo.

Anyway, let's start with the double sided geometry first.

膠帶

磁帶很有趣; 這不是你每天都遮蔽的東西！ 關(guān)于這個(gè)對(duì)象的主要注意事項(xiàng)是我創(chuàng)建了兩個(gè)不同的著色器？ 一個(gè)用于實(shí)際的卷帶，這是雙面幾何，一個(gè)用于撕掉膠帶？ 這是單面的。 這是一個(gè)重要的特征，因?yàn)槲覀儽仨毑煌�地遮蓋單面對(duì)象。 例如，我將使用雙面地理的子表面散射效應(yīng)在單面地理上是沒(méi)有意義的。

無(wú)論如何，我們先從雙面幾何開(kāi)始。

As you can see, it's once again pretty simple. I loaded in both my painted diffuse map (really simple, flat colors with some really subtle value/color differences ? I could have done this procedurally in Maya but happened to be in MARI) and a scratch/breakup map. I repeated the breakup map with a 2.5/1 UV ratio. (re-word this) It just needed to be squashed! This piped into both the bump slot and the spec slot of the alShader.

As you can see, it goes through an alRemapColor node before going into the spec slot. The reason for this is simple ? it's way too ?heavy', there's too much value difference. I only want this map to be subtle, so inside of the alRemapColor node I raised the gamma to a value of 8. If you'd test this out, you'd see that the values get flattened out a lot ? exactly what I was looking for.

你可以看到，這又是非常簡(jiǎn)單的。 我加載了我畫(huà)的漫反射圖（真的很簡(jiǎn)單，平淡的顏色，有一些非常微妙的價(jià)值/顏色差異，我可以在瑪雅程序上完成，但恰好在瑪麗），還有一個(gè)劃痕/破碎圖。 我用2.5 / 1紫外線比例重復(fù)分解圖。 （重新寫(xiě)這個(gè)）只需要壓扁！ 這被連接到凹凸槽和alShader的規(guī)格槽。

您可以看到，在進(jìn)入規(guī)格槽之前，它將通過(guò)一個(gè)alRemapColor節(jié)點(diǎn)。 這樣做的原因是簡(jiǎn)單的 ？ 這樣做太重了，有太多的價(jià)值差異。 我只希望這個(gè)地圖是微妙的，所以在alRemapColor節(jié)點(diǎn)的內(nèi)部，我把這個(gè)伽瑪提升到了8的值。如果你測(cè)試出來(lái)，你會(huì)看到這個(gè)值被壓扁了很多？ 正是我在找什么

An important visual attribute this tape has is some subtle sub surface scattering, so we have to make sure we include this. The attributes are really simple I only used one SSS layer, which had the same color as the diffuse map.

這個(gè)磁帶的一個(gè)重要的視覺(jué)屬性是一些微妙的子表面散射，所以我們必須確保我們包括這個(gè)。 屬性非常簡(jiǎn)單，我只使用一個(gè)SSS圖層，它與漫反射圖具有相同的顏色。

That's it for the double sided geo; let's move onto the single sided geometry. It's a bit more interesting!

這就是雙面地理; 讓我們移動(dòng)到單面幾何。 這有點(diǎn)更有趣！

To quickly sum this up, we have a refractive ?glue' shader, and a backlit ?paper' shader layered on top of each other with the remapped scratch map from earlier acting as a mask. Once I figured this out, it was once again, pretty easy! Inside of the shaders nothing complicated or special is going on. It's all about the layering.

為了快速總結(jié)一下，我們有一個(gè)折射式膠水著色器和一個(gè)背光？紙張著色器彼此頂層，重新映射的刮痕圖從以前作為掩模。 一旦我想到這一點(diǎn)，它再次是很容易！ 在著色器里面沒(méi)有什么復(fù)雜或特殊的。 這一切都是關(guān)于分層的。

An important attribute for the paper shader was backlighting. With this I emulated the translucency of the paper, just like I did with the SSS on the actual tape model.

In retrospect, I should have added more rough reflections on the tape on the grazing angles. I tried to do this with through my spec, but it didn't really work strong enough. It's something I looked over ? and should have faked this with my diffuse. It would have been a lot faster to render and easier to control.

Basically I would use a Sampler Info node to query my viewing angle, and map that into my U and V coordinates of a ramp node. Then in that ramp node I can plug in whatever I like and interpolate in between whatever I plugged in based on my viewing angle. Just like you would fake a cloth shader. It's explained pretty well over here.

Then I painted an opacity map for the edges of the tape, to give it a bit of a torn look. That's all, tape = done!

紙張著色器的一個(gè)重要屬性是背光。 這樣我仿效了紙張的半透明度，就像我在實(shí)際的膠帶模型上與SSS一樣。

回想起來(lái)，我應(yīng)該在放牧角度的膠帶上增加更多的粗糙反射。 我試圖通過(guò)我的規(guī)格這樣做，但它并沒(méi)有真正的工作足夠強(qiáng)大。 這是我看過(guò)的東西 并應(yīng)該用我的漫畫(huà)偽造了這個(gè)。 渲染速度要快得多，易于控制。

基本上我會(huì)使用Sampler Info節(jié)點(diǎn)來(lái)查詢我的視角，并將其映射到我的斜坡節(jié)點(diǎn)的U和V坐標(biāo)。 然后在那個(gè)斜坡節(jié)點(diǎn)中，我可以插入任何我喜歡的內(nèi)容，并根據(jù)我的視角插入任何插入的內(nèi)容。 就像你會(huì)偽裝一塊布料著色器。 在這里解釋得很好。

然后我畫(huà)了膠帶邊緣的不透明度貼圖，給它一點(diǎn)撕裂的樣子。 就是這樣，磁帶=完成！

Creating and rendering dust

This was a tricky one. I had never encountered a piece that needed a bit of dust sprinkled on top! I weighed up my options and decided that I'd try to do it as it would occur in real life, meaning rendering curves as thin hairs.

So then my only problem was: how do I create all these curves?! I looked online, but couldn't find any tool for Maya that was even remotely suitable. I didn't want to spend an incredible amount of time on just creating some dust, so I decided to paint on curves with Maya's PaintFX, using the popcorn preset. Pretty strange, having popcorn scattered all over my scene, but the curves that are used as a base for the PaintFX are pretty good. I converted the PaintFX into curves and rendered these as thin hairs. You can find a lot of information on rendering curves (with sets) in the Arnold documentation.

For the shading of the curves, I didn't use a Hair shader. I just used a standard alSurface shader with a really light brown diffuse color. It gave me the look I wanted!

The dust, however, is something I'm not 100% happy with. The shading is OK but the shape of the little dust particles just doesn't work fully. Writing a little dust PaintFX preset might be a cool thing to do sometime in the future!

創(chuàng)造和渲染灰塵

這是一個(gè)棘手的事情。我從來(lái)沒(méi)有遇到過(guò)需要一點(diǎn)灰塵灑在上面的東西！我衡量了我的選擇，并決定我會(huì)嘗試在現(xiàn)實(shí)生活中發(fā)生的事情，這意味著渲染曲線是細(xì)毛。

所以我唯一的問(wèn)題是：如何創(chuàng)建所有這些曲線？我在網(wǎng)上看，但找不到任何甚至遠(yuǎn)程適合的Maya工具。我不想花費(fèi)不可思議的時(shí)間來(lái)創(chuàng)造一些灰塵，所以我決定用Maya的PaintFX繪制曲線，使用爆米花預(yù)設(shè)。很奇怪，爆米花分散在我的場(chǎng)景，但是用作PaintFX的基礎(chǔ)的曲線是相當(dāng)不錯(cuò)的。我將PaintFX轉(zhuǎn)換成曲線，并將其渲染為細(xì)毛。您可以在Arnold文檔中找到關(guān)于渲染曲線（包含集）的大量信息。

對(duì)于曲線的陰影，我沒(méi)有使用Hair著色器。我剛剛使用了一個(gè)標(biāo)準(zhǔn)的alSurface著色器，具有非常淺的棕色漫反射色彩。它給了我想要的樣子！

但是，灰塵是我不是100％的快樂(lè)。陰影是好的，但是灰塵顆粒的形狀不能完全正常工作。寫(xiě)一點(diǎn)灰塵PaintFX預(yù)設(shè)可能是一個(gè)很酷的事情在未來(lái)做某個(gè)時(shí)間！

Compositing

The final step of the process! For this image not much compositing work was needed ? it came out pretty decent out of the render engine!

I added some colour corrections for some individual objects based on the ID masks that I rendered out, some overall grading, and a bit of grain and the depth of field.

With every project I do I try to learn new things, explore new techniques. In this project I wanted to try out Sony's SPI-ANIM OCIO profile instead of the default 2.2 gamma curve in Nuke. There's way too much to it to explain in this post, but with a quick Google you'll be reading about it in no time.

It's all about the maths behind going from your linear image to what you display on your monitor. The default is a 2.2 gamma curve, but there are many other options, which actually prove to look better. The highlights were not blown out, and everything had quite a film like look. Pretty cool! Try it yourself

Overall I learned A LOT whilst creating this image. I absolutely loved diving into all these mini details. I definitely think one of my next pieces will once again be a small scenery. It's just SO much fun! Hope this was a little bit useful, and don't hesitate to contact me if you have any questions or remarks. I'm always looking to learn!

合成

最后一步的過(guò)程！對(duì)于這個(gè)圖像，不需要很多的合成工作？它呈現(xiàn)出相當(dāng)不錯(cuò)的渲染引擎！

我根據(jù)我提出的ID掩碼，一些整體分級(jí)，以及一些紋理和景深，為一些單獨(dú)的對(duì)象添加了一些顏色校正。

我每個(gè)項(xiàng)目都會(huì)嘗試學(xué)習(xí)新事物，探索新技術(shù)。在這個(gè)項(xiàng)目中，我想嘗試索尼的SPI-ANIM OCIO配置文件，而不是Nuke中默認(rèn)的2.2伽瑪曲線。在這篇文章中有太多的解釋，但是用一個(gè)快速的Google，你可以隨時(shí)閱讀它。

這是關(guān)于從線性圖像到您在顯示器上顯示的數(shù)學(xué)背后的數(shù)學(xué)。默認(rèn)是2.2伽瑪曲線，但還有許多其他選項(xiàng)，實(shí)際上證明是更好看。亮點(diǎn)沒(méi)有被吹滅，一切都有一個(gè)像電影一樣的電影。很酷啊自己試試

總體而言，我創(chuàng)造了這個(gè)形象時(shí)學(xué)到了很多東西。我絕對(duì)喜歡潛入所有這些迷你細(xì)節(jié)。我絕對(duì)認(rèn)為我的下一個(gè)作品將再次成為一個(gè)小風(fēng)景。這只是很有趣！希望這有點(diǎn)有用，如果您有任何問(wèn)題或意見(jiàn)，請(qǐng)隨時(shí)與我聯(lián)系。我一直在尋找學(xué)習(xí)！