制作“稻草人”

在本文中，我將解釋制作稻草人圖像的過程。我將涵蓋創(chuàng)作的所有方面，例如插圖、造型，以及我在下面使用的紋理。

In this article, I will explain the process of making my Scarecrow image. I will cover all aspects of creation, such as the illustration, modelling and also the texturing which i have used the below

概念

因為這個插圖是針對CGTalk的“奇怪的行為”比賽的，所以我必須非常小心地為最初的想法，計劃和基本的概念階段做我想做的事情。這個想法很簡單：我想講講今天的問題以及環(huán)境發(fā)生的巨大影響。我認為這是一個很好的例子。

所以，我想到的第一件事就是選擇一個角色。我決定在田里做一個稻草人。一旦角色決定了，我開始研究最初的草圖。我總是盡量找到盡可能多的參考材料，因為這可以幫助我更快地定義事物，也可以作為紋理外觀的一些很好的信息。

稻草人不得不看上去很可信，我想要融入一個經(jīng)典的外觀：巨大的帽子，舊褲子，破洞的衣服，外露的稻草部分，舊木棍，巨大的靴子和大眼睛。雖然稍微夸大了一些比例

Concept

Because the illustration was for a "Strange Behaviour" contest on CGTalk, I had to be very careful with the initial idea, the planning and the basic concept stage for what I wanted to do. The idea was simple: I wanted to tell the story about today's problems and the huge impact of what is happening to the environment. I thought this could be a wonderful opportunity for an illustration.

So, the first thing that came to my mind was to select a character. I decided to make a scarecrow in a field. Once the character had been decided, I began working on the initial sketch. I always try to find as much reference material as possible as this helps me to define things quicker and also serves as some nice information as to how the textures should look.

The scarecrow had to look believable and I wanted to incorporate a classic look: huge hat, old trousers, ripped clothes, exposed parts filled with straw, old wooden sticks, huge boots and big eyes. The proportions needed to be human, although slightly exaggerated

第二階段是想象烏鴉。烏鴉必須看起來像飛行的邪惡的生物，他們試圖向稻草人發(fā)泄他們的憤怒。最后，我想保留那些大頭，爪子和邪惡的紅眼睛的鳥。 有了兩個人物，故事很簡單。

由于附近地區(qū)污染的水，烏鴉已經(jīng)發(fā)生了變異。 環(huán)境中充滿了輻射，使鳥兒變得兇悍，于是他們就對過去害怕他們的稻草人大發(fā)雷霆。 稻草人試圖逃跑，但它被困在泥潭里。

環(huán)境必須是抑郁，骯臟，污染; 它必須充滿輻射，灰塵和煙霧; 它不得不反映那個“時刻”。

我畫了一些構(gòu)圖元素的快速草圖，看看它是如何在最終形象中起作用的。 當然，在這個階段，沒有什么是刻在石頭上的！

The second stage was imagining the crows. The crows had to look like flying evil creatures who were trying to wreak their anger upon the scarecrow. In the end, I wanted to retain the same bird look with bigger heads, claws and evil red eyes. With 2 characters, the story was simple.

Because of the polluted water in the nearby area the crows had mutated. The environment has been filled with radiation which has caused the birds to become aggressive, and so they wreak their anger upon the nearby scarecrow that has frightened them in the past. The scarecrow tries to escape, but it is stuck in the mud...

The environment had to be depressive, dirty, polluted; it had to be filled with radiation, dust and smoke; it had to reflect that "moment".

I drew a few quick sketches for the composition elements, to see how it would all work in the final image. Of course, at this stage, nothing was carved in stone!

造型

一旦概念階段建立起來，我就開始建模實際的場景。 在這個階段，我開放了所有新的想法，并改變了主要人物的實際概念。

稻草人：我從盒子里建立了基體幾何，并使用了多邊形建模技術(shù)。 一旦確定了基本的比例，我開始研究主要輪廓。 一旦剪影被定義，我開始建模的細節(jié)，如衣服的皺紋，口袋，小補丁，紐扣，繩索和稻草。 對于紐扣，我使用了一個圓柱體，繩子是一個圓形的基本形狀的放樣表面。 對于腰帶，我使用了一個細分的平面，形成了正確的形狀，然后我做了一些洞，擠出了臉。 皮帶扣是一個改進的圓環(huán)

Modelling

Once the concept stage had been established, I began modelling the actual scene. At this stage, I was open for all the new ideas and changes to the actual concept of the main characters.

Scarecrow: I established the base body geometry from a box, and used the polygon modelling technique. Once the basic proportions had been established, I began working on the main silhouette. Once the silhouette has been defined, I began modelling details, like clothing wrinkles, pockets, small patches, buttons, rope and straw. For the buttons I used a cylinder, and the rope was a lofted surface with basic shape as a circle. For the belt, I used a subdivided plane and formed it into the correct shape, and then I made holes and extruded the faces. The belt buckle was made from a modified torus

草帽是用瑪雅的油漆效果制成的，使用里面的草帽（禾草）。 我制造了幾根小稻草，放在稻草人身上。

The straw was made with paint effects in Maya, using the brush inside visor (grasses-straw). I created a few small strands of straw and put them on the scarecrow.

烏鴉：這是烏鴉的基本過程。 我用一個盒子把它塑造成所需的形狀

Crow: Here is the basic process for the crow. I used a box and shaped it into a desired form

羽毛是由一個簡單的平面和UV繪制的。 然后我簡單地把它復制成一個翅膀。 我也用一個不透明的來形成一個羽毛，以便更快的渲染

The feathers were made from a simple plane and UV mapped. Then I simply duplicated it and formed them into a wing. I also used an opacity mask to form a feather, for faster rendering

對于小麥，我創(chuàng)造了一個小種子，然后復制，并旋轉(zhuǎn)它，直到我得到了整個殼。 然后，我模擬了一個圓柱的莖，使其更加統(tǒng)一。 為了創(chuàng)造樹葉，我使用了一個平面，并將其正確地塑造成了正確的形狀。

其他物體，如桶，木棍和發(fā)電廠，都是由圓筒制成的。 對于草地，我用油漆效果來創(chuàng)造小草。 我通過復制它們將草地播種到田地網(wǎng)上。

For the wheat, I created a small seed then duplicated and rotated it until I got the whole husk. Then I modelled the stem from a cylinder and made it more uniform. To create leaves, I used a plane and properly formed it into the right shape.

Other objects, such as the barrel, wooden sticks, and power plants, were all made of cylinders. For the grass I used paint effects to create small strands of grass. I sowed the grass onto the field mesh by duplicating them.

ZBrush

一旦我對建模階段感到滿意，我決定使一些部分更詳細，使用法線貼圖來加快渲染速度。 為了創(chuàng)建正常的地圖，我把稻草人的OBJ格式導入ZBrush，并開始雕刻每一個稻草人。 因為我不得不在Maya里面生成法線貼圖，為了更容易的烘焙，我把每一個多邊形的多邊形保留了最多200萬個。 這個想法是在較低分辨率的幾何體上使用高多邊形幾何體，而不會丟失所有的細節(jié)。 我決定使用法線貼圖來代替凹凸貼圖。

ZBrush

Once I was satisfied with the modelling stage I decided to make some parts more detailed, using normal maps for faster rendering. To create normal maps I imported the OBJ format of the scarecrow into ZBrush and began sculpting each piece of the scarecrow individually. Because I had to generate normal maps inside Maya, I kept the poly count at a maximum of 2 million polygons for each piece for easier baking. The idea was to use high polygon geometry on lower resolution geometry, without losing all the detail. I decided to use normal maps instead bump maps.

在ZBrush中，我使用標準畫筆來定義大的皺紋。 我用光滑的工具來實現(xiàn)一個美麗的過渡。 在定義了大皺紋之后，我使用懶惰的鼠標功能進行了細化處理，以平滑曲線。 我通常在細分級別4使用懶惰的鼠標，以避免虛線。 一旦雕塑完成，我將高分辨率網(wǎng)格作為OBJ輸出到Maya中。

In ZBrush, I used a standard brush to define large wrinkles. I used the smooth tool to achieve a beautiful transition. After large wrinkles had been defined, I went into smaller detail using the lazy mouse feature to smooth curved lines. I usually use the lazy mouse at subdivision level 4, to avoid doted lines. Once the sculpting had been completed I exported the high poly mesh into Maya as an OBJ.

電子郵件

對于桶，我已經(jīng)創(chuàng)建了UV貼圖和顏色紋理。 所以我所做的就是在Photoshop中使用顏色紋理并對其進行去色。 然后，我使用了Levels，并調(diào)整每一層的亮度/對比度來創(chuàng)建一個面具。 當一個面具已經(jīng)創(chuàng)建，我用它在ZBrush掩蓋的強度。 這個面具然后作為雕刻的模板，它也幫助我微調(diào)桶上的細節(jié)。

Email

For the barrel, I had already created UV maps and colour texture. So what I did was to use the colour texture in Photoshop and desaturate it. Then I have played with Levels and adjusted the brightness/contrast on each layer to create a mask. When a mask had been created I used it in ZBrush for masking the intensity. This mask then served as a template for sculpting and it also helped me to fine-tune the details on the barrel

法線貼圖

要創(chuàng)建法線貼圖，我將高多邊形幾何體導出為OBJ格式，并在Maya中使用它。 在低多邊形幾何體頂部具有較高的多邊形幾何圖形以使對象重疊很重要。 低多邊形模型必須被映射。

對于照明/陰影，我選擇了傳輸?shù)貓D。

在“轉(zhuǎn)換地圖”窗口的“目標網(wǎng)格”卷展欄下，我在“源網(wǎng)格”下添加了低多邊形和高多邊形。 在“輸出”卷展欄中，我選擇了法線貼圖，并設(shè)置要在哪里輸出紋理。 地圖空間設(shè)置為切線。

在Maya的常用輸出卷展欄中，寬度和高度的分辨率設(shè)置為：“采樣質(zhì)量”為高，“過濾器類型”為三角形，“忽略鏡像的面”被勾選。

當所有的高多邊形零件都烘焙到法線圖上時，我將它們組合在Photoshop中以創(chuàng)建一個紋理。

Normal Maps

To create normal maps I exported the high polygon geometry to OBJ format and used it in Maya. It's important to have high polygon geometry on top of low polygon geometry so that the objects overlap. The low polygon model had to be mapped.

For the under lighting/shading I selected Transfer Maps.

In the Transfer Maps window, under the Target Meshes rollout, I added low poly and high poly under Source Meshes. In the Output rollout, I selected normal map and set the destination of where to export the texture. The Map space was set to Tangent.

In Maya's common output rollout, the resolution for the width and height was set up to: "Sampling quality" to High, "Filter type" to Triangular and "Ignore Mirrored Faces" was ticked.

When all the high polygon parts had been baked onto a normal map, I combined them in Photoshop to create just one texture

1，對于細節(jié)部分，已經(jīng)為接縫，材質(zhì)貼圖，針跡等部分創(chuàng)建了高度貼圖。通過使用Photoshop中的法線貼圖過濾器插件，我從高度貼圖創(chuàng)建了一個法線貼圖。

2，Maya制作的正常地圖。

3，由高度圖制作的法線貼圖覆蓋在Maya中生成的法線貼圖上。 這給了我足夠的細節(jié)來渲染。

1、For the fine details, the height map had been created for parts like the seams, material textures, stitches, etc. By using the Normal map filter plug-in in Photoshop, I created a normal map from the height map.

2、A normal map baked from Maya.

3、The normal map, made from height map, was overlaid on top of the generated normal map made in Maya. This gave me enough detail for rendering.

紋理

建模階段完成后，我開始研究紋理。 但是，首先，我必須打開所有的模型！ 對于大多數(shù)我使用平面映射投影的部分，除了我使用圓柱映射的圓形部分。 由于圖像是靜態(tài)的，所以我把所有的UV接縫放在背面。 通過這樣做，我避免了紋理上所有接縫的麻煩。這里有一個簡單的解釋，把夾克貼到稻草人身上……

Texturing

When the modelling stage was complete, I began working on the textures. But, first of all, I had to unwrap all of the models! For most parts I used planar mapping projection, except for the round parts where I used cylindrical mapping. Because the image was static, I put all UV seams on the back side. By doing this I avoided all the troubles with seams on the textures. Here is a simple explanation of texturing the jacket on the scarecrow...

顏色映射

首先，我為稻草人的每個部分定義了基本的顏色。 對于夾克，我想要一個紅色，所以我所有的外套部分涂成了紅色。

第二步是添加一些陰影來獲得基本的形狀。 對于這一步，我使用法線貼圖中的藍色通道，并將其設(shè)置為正片疊底。 （我也可以使用從高分辨率幾何到低多邊形烘焙的環(huán)境遮擋（AO）通道，但是由于我正在創(chuàng)建一個靜止圖像，因此我只是在整個圖像的末尾烘焙了AO。

這件夾克是由皮革制成的，所以我使用了3DTotal Textures DVD Collection（http://www.3dtotal.com/textures）中的皮革紋理。 在使用紋理之前，我去飽和并調(diào)整亮度/對比度以保持基色。 然后，我將皮革紋理覆蓋在底色上。

Colour Map

First I defined basic colours for every part of the scarecrow. For the jacket, I wanted a red colour so I painted all the jacket parts with red.

The second step was adding some shading to get basic shapes. For this step, I used the blue channel from the normal map and set it to Multiply. (I could also have used an ambient occlusion (AO) pass, baked from high resolution geometry to low polygon, but since I was creating a still image, I simply baked AO at the end for the whole image.)

The jacket was to be made from leather, so I used a leather texture found in the 3DTotal Textures DVD Collection (http://www.3dtotal.com/textures). Before using the texture though, I desaturated and adjusted the brightness/contrast to retain the base colour. I then overlaid the leather texture on top of the base colour .

1，下一步是打破基本的顏色，并添加更多的老化的外觀。 我使用了一種污垢質(zhì)地，并將其覆蓋在皮革質(zhì)地的頂部，然后將不透明度調(diào)整到約50％。

2，為了增加更多的細節(jié)和定義材料，我為布料創(chuàng)建了接縫。 接縫用硬邊刷小刷子。 我用了一個幾乎是白色的顏色，因為它被覆蓋在污垢層的頂部。 畫完接縫之后，我在這些接縫處做了陰影，給人一種深度的印象。 對于更不規(guī)則的外觀，我使用白色小刷子將圖層設(shè)置為“屏幕”模式，添加了小高光。

3，我用一種較低的不透明度的淺紅色將高光涂抹到一個新的層上，其中皺紋最明顯。

1、The next step was to break up the base colours and add more of an aged look. I used a dirt texture and overlaid it on top of the leather texture, and then adjusted the opacity to about 50%.

2、To add more details and to define the material a bit more, I created seams for the fabric. Seams were painted by using a small brush with hard edges. I used an almost white colour because it was to be overlaid on top of the dirt layer. After painting seams, I made shadows around those seams to give an impression of depth. For a more irregular look I added small highlights using a white, small brush with the layer set to Screen mode.

3、I used a lighter red colour with a low opacity to paint highlights onto a new layer, where wrinkles were mostly evident .

1，用深紅色的刷子將新的陰影添加到新圖層，并將模式設(shè)置為柔光。 陰影通常有助于定義小細節(jié)上的法線貼圖，例如皺紋和接縫。

2、在這里，我偽造了一些紐扣與夾克相遇的陰影。

1、With a dark red brush, new shadows were added onto a new layer and the mode was set to Soft light. Shadows usually help to define normal maps on small details, such as wrinkles and seams.

2、Here, I faked some of the shadows where the buttons meet the jacket.

不透明度地圖

對于衣服的磨損，我制作了簡單的不透明貼圖。黑色像素是透明的，而白色像素是可見的。我用同樣的方法處理鳥類的羽毛和小麥葉子。這是一種快速而有效的方法，將更多的細節(jié)添加到簡單的多邊形中。

Opacity Maps

For wear and tear on the clothing I made simple opacity maps. Black pixels are transparent, while white pixels are visible. I used the same technique for the birds' feathers and wheat leaves. This was a quick and efficient way of adding more details to simple polygons .

高光貼圖

高光貼圖定義了您正在制作的材質(zhì)，所以鏡面對于某些材質(zhì)的表現(xiàn)如何非常重要。我使用顏色紋理作為基礎(chǔ)來創(chuàng)建高光貼圖。因為我有以前的顏色映射的所有圖層，我可以分別調(diào)整每個圖層。

Specular Maps

Specular Maps define the material you are making, so it is very important how the specular behaves for certain materials. I used the colour texture as a base to create a Specular map. Because I had all the layers from the previous colour map, I was able to adjust each layer separately.

1，所有的圖層現(xiàn)在都是灰度的。在新圖層上，我用不同的畫筆繪制了一些白色高光。該圖層設(shè)置為“屏幕”模式，大部分高光部分都涂上了材質(zhì)應(yīng)該發(fā)亮的地方。這些是邊緣，一些皺紋，腫塊和照明首先會撞擊表面的地方，例如鼻子，下唇，臉頰，膝蓋，口袋，鞋子的前面，接縫等。注意：對于棉花和羊毛來說，鏡面幾乎是黑色，因為這些表面通常具有最小的鏡面性。潮濕的部分，像污漬和縫線，有小亮點，以區(qū)別于其他材料。

2，第二步是實際的材質(zhì)紋理。我調(diào)整了亮度和對比度，從皮色紋理中得到了一些小的細節(jié)，這些紋理是從彩色地圖中使用的。

3，污垢質(zhì)地被用來打破統(tǒng)一的亮點。我還強調(diào)了衣服皺紋，縫線和紐扣陰影之間的陰影。

All layers were now greyscale. On a new layer, I painted some white highlights with different brushes. The layer was set to Screen mode and most of the highlights were painted where the material was to be shiny. These were edges, some wrinkles, lumps and where lighting would hit the surface first, such as the nose, bottom lip, cheeks, knees, pockets, front of shoes, seams, etc. Note: for the cotton and wool the specular is almost black, because these surfaces usually have minimal specularity. The wet parts, like the stains and stitches, have small highlights to distinguish themselves from other materials.

The second step was the actual material texture. I adjusted the brightness and contrast to get small details out of the leather texture, which was used from the colour map.

The dirt texture was used to break up the uniform highlights. I also emphasised the shadows between clothing wrinkles, seam and button shadows .

如果您突出一個方面比另一個更重要的圓形部分，如桶和發(fā)電廠，則更加現(xiàn)實。 這也有助于定義更多的圓形表面

對于金屬部件，我還強調(diào)了油漆和鐵銹之間的邊緣，并且弄臟了任何泄漏的污漬。

Round parts, such as the barrel and power plant, achieve much more realism if you highlight one side more than the other. This also helps in defining a round surface a lot more.

For metallic parts, I also highlighted edges between paint and rust, and darkened any leaking stains.

燈光

對于閃電和渲染，我用Max。 首先，我設(shè)置了場景并把所有元素放在一起。 照明非常簡單：一個黃色的聚光燈位于左上角，投射陰影開啟。 我使用光線跟蹤陰影和衰減被設(shè)置為相反。 第二個藍色的聚光燈位于右側(cè)。 沒有陰影和衰減被設(shè)置為相反的。 一個暗藍色的Omni燈，強度低，位于右側(cè)，后面是角色。 陰影和衰變被設(shè)置為相反的。 最后一盞燈是一個黃色的Omni燈，位于字符下方的右側(cè)，陰影開啟，光線追蹤陰影和反轉(zhuǎn)衰減。

Lighting

For lightning and rendering I used Max. First, I setup the scene and put all the elements together. The lighting was very simple: one yellow Spot light was positioned in the top left with casting shadows turned on. I used ray traced shadows and decay was set to inverse. A second blue Spot light was positioned on the right side. No shadows and decay was set to inverse. A dark blue Omni light, with low intensity, was positioned on the right side, behind character. Shadows and decay were set to inverse. The last light was a yellow Omni light which was positioned on the right side, below the character, with shadows turned on and with ray traced shadows and inverse decay .

物料

我為每個模型使用了一個簡單的blin著色器 - 我填充了漫反射，鏡面反射，不透明和凹凸槽。 對于每個部分我也玩過鏡面，顏色和光澤滑塊。

對于桶，我用了菲涅耳反射衰減。 在地圖1下使用了一個反射遮罩，以獲得輕微的衰減效果

Materials

I used a simple blinn shader for every model - I filled the diffuse, specular level, opacity and bump slots. For each part I also played with the specular, colour and glossiness slider .

For the barrel I used a falloff with fresnel reflection. A reflection mask was used under map 1 to get a slight falloff effect

渲染

為了渲染，我使用了Mental Ray。 這是我使用的設(shè)置它以高分辨率渲染，所以我必須渲染通過，所以我使用漫反射，光照，鏡面反射和陰影通過。 在這個階段，我還為所有模型創(chuàng)建了環(huán)境遮擋。 為了便于合成和渲染，我分別渲染了每個模型。 最后，當所有的模型已經(jīng)被渲染，我把它們合成在Photoshop中。

Rendering

For rendering I used Mental Ray. Here are the settings I used  It was rendered at high resolution so I had to render in passes, and so I used diffuse, lighting, specular and shadow passes. At this stage, I also created ambient occlusion for all the models. For easier compositing and rendering, I rendered each model separately. In the end, when all models had been rendered, I composited them in Photoshop.

以下是在Photoshop中如何合成圖層的簡化視圖。

Here is the simplified view on how the layers have been composited in Photoshop.

在Photoshop中混合模式

陰影：相乘

高光：疊加減少不透明度

環(huán)境遮擋：覆蓋

霧：硬光減少不透明度

霧效果：屏幕

假背光：柔光

結(jié)論

我希望你從這篇文章中學到了一些新的東西。

Blending modes in Photoshop

Shadows: Multiply

Specular: Overlay reduced opacity

Ambient Occlusion: Overlay

Fog: Hard Light reduced opacity

Fog effect: Screen

Faked back light: Soft light

Conclusion

I hope you learned some new things from this article.