制作“悲傷的外星人”（二）

其余的場(chǎng)景在材質(zhì)上非常簡(jiǎn)單。玩具盒未包裝，用Photoshop完成;其余的工作是使用照片紋理和基本的平面映射或立方體映射來(lái)為程序添加細(xì)節(jié)。一些紋理的構(gòu)成可以在圖11中看到。

The rest of the scene is pretty simple in terms of texturing. The toy box was unwrapped and completed in Photoshop; the rest was done using photo textures and basic planar mapping for adding detail or cubic mapping for procedurals. The composition of some of the textures can be seen in Fig.11.

圖11

成分和照明

Composition and Lighting

燈光和背景組成是這項(xiàng)工作中最困難的部分。我無(wú)法決定我想從現(xiàn)場(chǎng)得到什么。我試著用顯示器做一個(gè)白天的設(shè)置，但是很無(wú)聊(圖12)。于是，我嘗試了一種不同的構(gòu)圖，用夜光照明，在角色的方向，但我意識(shí)到它不是適合場(chǎng)景的格式，或者作為未來(lái)的展示的例子(圖13)。

The lighting and scene composition were the most difficult parts of this work. I couldn't decide what I wanted from the scene. I tried to make a daylight setup with monitors on, but it was quite boring (Fig.12). So then I tried a different composition with night lighting, in portrait orientation, but I realized that it wasn't a suitable format for the scene or as an example for a future showreel (Fig.13).

圖12

圖13

我使用灰色材料來(lái)準(zhǔn)備基本的照明;通過(guò)這樣做，你可以更好地看到效果，而且你不會(huì)被物質(zhì)的顏色所打擾。一開(kāi)始，我用了一盞燈和一盞燈來(lái)點(diǎn)亮另一盞燈。對(duì)于關(guān)鍵的光，我使用一個(gè)基本的燈罩，有精確的陰影和光的放置，這是我想要的。對(duì)于邊緣光，我使用了一個(gè)非常強(qiáng)烈的點(diǎn)直接指向外星人的大腦，以支持它的地下散射和形狀。

I used grayshade materials for preparing my basic lighting; by doing this you can better see light colors and intensities, and you're not disturbed by material colors. For the start I used a key light for a lamp and a rim light for another lamp. For the key light I used area and I modeled a basic lamp shade, to have exact shadow and light placement, which I wanted. For the rim light I used a pretty intense spot directing right onto the alien's brain, to support its subsurface scattering and shape.

把這些燈裝好后，我試著像個(gè)攝影導(dǎo)演一樣思考。揚(yáng)聲器太暗，所以我加了一個(gè)聚光燈指向它的上部。另外，電纜線是不可見(jiàn)的，左邊的部分有點(diǎn)暗，所以我又加了一個(gè)點(diǎn)。我還添加了一些填充燈來(lái)增加氣氛。最后的場(chǎng)景包括六盞燈(圖14)和一個(gè)反射框，為外星人的眼睛增添了美好的火花。我還使用了全局照明來(lái)增加場(chǎng)景的真實(shí)性。

After placing those lights I was trying to think like a director of photography. The speaker was too dark and so I added a spot light pointing to its upper part. Also the cables were not visible and the left part of the scene was a little bit dark, so I added another spot. I also added some fill lights to add to the ambience. The final scene contains about six lights (Fig.14) and a reflection box to add nice spark to the alien's eyes. I also used global illumination to add a little more realism to the scene.

圖14

材質(zhì)和渲染

Shading and Rendering

這個(gè)陰影很容易，除了外星人。當(dāng)時(shí)我正在學(xué)習(xí)modo，我對(duì)它的著色方法有點(diǎn)迷惑。但過(guò)了一段時(shí)間，我發(fā)現(xiàn)它非常有用和有效。我在modo 501中工作，皮膚著色器直到601才被完成，所以我基于mental ray的皮膚做了自己的皮膚。只要添加四層不同顏色和sss偏好的紋理，我就會(huì)從我的多色畫(huà)中生成這些紋理。我還為大腦材料做了一個(gè)稍微不同的設(shè)置，用一個(gè)面具將它無(wú)縫地融入到皮膚中，這在modo中是非常容易和有效的。您可以在圖15中看到皮膚和紋理的渲染。

The shading was pretty easy, except for the alien. I was learning modo at the time, and I was a little bit confused by its approach to shaders. But after a while, I found it very useful and effective. I was working in modo 501 and skin shader wasn't implemented until 601, so I made my own skin based on mental ray's one. Simply adding four layers of textures with different colors and sss preferences, I generated those textures from my polypaint. I also made a slightly different setup for the brain material and seamlessly blended it into the skin using a mask, which is a very easy and effective thing to do in modo. You can see the render tree for the skin and textures in Fig.15.

圖15

其余的著色器非常簡(jiǎn)單，我使用了modo的預(yù)置。我找到了我需要的著色器，將它應(yīng)用到我的模型上，并做了一些修改，使它適合我的場(chǎng)景。我還在庫(kù)中添加了自己的著色器，這樣我就可以快速地重用它們。

The rest of the shaders are really simple and I used modo's presets heavily. I found the shader I needed, applied it on my model and made some changes to make it suitable for my scene. I also added my own shaders to the library, so I could quickly reuse them.

對(duì)于幾乎所有的材料，我使用了正常的貼圖，因?yàn)槲野l(fā)現(xiàn)，表面凹凸是非常重要的，當(dāng)它讓你的場(chǎng)景變得真實(shí)，瘋狂的使用碰撞，從照片生成法線貼圖是非常簡(jiǎn)單和非常有效的。所有的材料都可以在圖16中看到。

For almost all the materials I used Normal maps as I've found that surface bump is very important when it comes to making your scene real and using Crazy Bump for generating Normals maps from photos is incredibly easy and very effective. All the materials can be seen in Fig.16.

圖16

至于渲染設(shè)置，我之前說(shuō)過(guò)，我用的是modo。這很簡(jiǎn)單，沒(méi)什么特別的;我要提到的唯一一件事就是我使用了一個(gè)25毫米的鏡頭，并且我想要做一個(gè)相當(dāng)深的領(lǐng)域。對(duì)于這種類型的場(chǎng)景，幾乎不可能使用基于深度后處理的zblur，因?yàn)樵谶吘墪?huì)得到奇怪的工件。有兩個(gè)解決方案。一是，將你的場(chǎng)景分割成幾層，然后分別渲染和模糊它們，二是，簡(jiǎn)單地使用渲染DOF。

As for the render setup, I said before, I used modo. It was quite easy and nothing special; the only thing I will mention is that I used a 25mm lens and as I wanted to make a pretty depth of field. For this type of scene is almost impossible to use post-processed zblur based on depth, because you'll get odd artifacts at the edges. There are two solutions. Once, separate your scene into a couple of layers, and render and blur them separately, or two, simply use a brute force render DOF.

我選擇了第二個(gè)選項(xiàng)，所以我設(shè)置了很高的抗鋸齒效果來(lái)獲得一個(gè)干凈的效果。在modo中，我也直接使用了鏡頭失真，因?yàn)樵诂F(xiàn)實(shí)世界中，25毫米鏡頭的失真是很明顯的。您可以在圖17中看到我的整個(gè)渲染設(shè)置。

I chose the second option, so I set antialiasing up very high to get a clean effect. I also used lens distortion directly in modo, as it helped the final image a lot because a 25mm lens distortion is obvious in the real world. You can see my entire render setup in Fig.17.

圖17

最后的渲染是6000 x 3374，渲染時(shí)間大約是在四個(gè)小時(shí)。但是如果你考慮所有的渲染效果，SSS, GI，很多燈等等，我認(rèn)為modo做了一件很棒的工作，我很確定其他的渲染器會(huì)更慢。

The final render was in 6000 x 3374 with the render time around four hours on a hardcore workstation setup. But it's great if you consider all the render effects, SSS, GI, a lot of lights, etc. I think that modo did an awesome job and I am quite sure that other renderers would be slower.

后期制作

Post-production

在過(guò)去的五年中，我一直在VFS行業(yè)工作，所以后期制作是我的日常工作。就像很多人一樣，我用Nuke來(lái)處理后處理，這個(gè)場(chǎng)景非常簡(jiǎn)單，就像你在Nuke上看到的(圖18)。

For the last five years I've been working in the VFS industry, so post-production is my daily bread. Like a lot of the world, I use Nuke for post-processing and for this scene it was fairly simple, as you can see on Nuke's tree (Fig.18).

圖18

最后，加入了一個(gè)眾所周知的組合:色差和谷物。我總是提醒人們明智地使用這個(gè)組合，因?yàn)樗�可以幫助你完成你的形象，但也可以很容易地摧毀它。只要觀察正常的照片就可以了。

Finally it came time to add a well-known combination: chromatic aberration, vignette and grain. I always caution people to use this combination wisely as it can help your image, but can just as easily destroy it. Just observe normal photos and that should help.

這是純渲染和最終圖像的比較(圖19)。

Here's a comparison of the pure render and the final image (Fig.19).

圖19

這是最終圖像的放大版本(圖20)。

And here's a larger version of the final image (Fig.20).

圖20