教程來自：
英國倫敦3D藝術家Şefki Ibrahim
翻譯：CG模型網-嘉兒
《THE SILVINA PROJECT》
《西爾維娜項目》
software
Maya、R3DS Wrap、Mari、ZBrush
Arnold、Photoshop、Mudbox
Eyes眼睛
The front part of the sclera geometry is separated and unwrapped in a single UV tile.
The back of the sclera is positioned in the corner since its resolution is not a priority.
鞏膜前部的幾何圖形被分離開來，並在單個UV中展開。
鞏膜的背面位於角落，因為其分辨率不是優先事項。（虹膜前部貼圖繪製精細，背部幾乎看不到所以精細度低）
Sclera Albedo鞏膜反照率圖
This process was also repeated for the iris.
All of the eye textures were created at 4K res.
這個過程也被重複到虹膜上。
所有的眼睛紋理都是在4K分辨率下創建的。
編輯
lris Albedolris反照度
Screenshots from Maya viewport of the sclera, iris, pupil and caruncle geometry. Note, the circumference of the iris extends the size of the cormea to avoid gaps and shadowing.
鞏膜、虹膜、瞳孔和角膜幾何圖形的Maya視口截圖。注意，虹膜的周長會擴大皮質的大小，以避免縫隙和陰影。
When I had finalised the eyeball placement within ZBrush and matched its positioning to the scan, the eyes were imported into myMari scene. This way I could make sure that my projection was matching the reference in regards to how large the iris should be as wellas where the veins should sit in the opening of the eye.
The projection was made using the references provided for both the right and left sclera and iris geometries. It was important for me to aim for high realism in this piece, so having the asymmetrical eye texture maps were really important.
The rest of the sclera texture was hand-painted with a combination of procedural layers.
當我在ZBrush中最終確定了眼球的位置，並將其定位與掃描結果相匹配後，眼睛被導入到我的Mari場景中。這樣，我就可以確保我的projection與參考的虹膜應該有多大，以及靜脈在眼球開口處的位置相匹配。
投影時，我使用了左右鞏膜和虹膜的幾何形狀的參考資料。對我來說，這幅作品的目標是高逼真度，所以擁有不對稱的眼睛紋理貼圖非常重要。
鞏膜紋理的其餘部分則採用了手繪的方式，結合程序化的圖層進行繪製。
The texturing process is very similar to the tongue mentioned earlier.I used the diffuse map to derive bump maps by applying Photoshop filters. These were in turn used to create the specular, roughness and subsurface maps, with the addition of hand-painting and procedural texturing.
Some of the sclera texture maps are presented below.
The transmission map is used to create the cornea of the eye(a circular ramp can also be used within Maya).
紋理處理過程與前面提到的舌頭非常相似，我使用diffuse map漫反射貼圖，通過應用Photoshop濾鏡推導出bump maps凹凸貼圖。這些繼而用來創建specular高光、roughness粗糙度和subsurface maps亞表面貼圖，再加上手繪和procedural texturing程序紋理貼圖。
一些鞏膜紋理圖如下所示。
透射貼圖用於創建眼睛的角膜（在Maya中也可以使用circular ramp圓形斜面）。
Changes to the eyes have been made sincel
眼睛已經變得真實
Like the teeth, it's important to have subsurface on the sclera and caruncle geometries in order to blend these components into the eyelids (and each other) more seamlessly. The randomwalk v2 SSS model was chosen for this after some testing.
It's important for the transmission blend to be smooth and have a high feathered edge, meaning that the blend between the sclera and iris is blurred. A sharp transition will create the CG eye look.
I tend to create a circular selection around the iris map in Photoshop to darken the outer edge, which can define the outline of the iris, but this should be very subtle and very much depends on the reference・
就像牙齒一樣，鞏膜和眼角膜上有subsurface是很重要的，這樣才能讓這些部件更完美地融入到眼皮（以及彼此之間）。為此，經過一番測試，我們選擇了Randomwalk v2 SSS模型。
重要的是，transmission blend傳輸融合要smooth平滑，邊緣要有很高的feathered edge羽化度，也就是說鞏膜和虹膜之間的融合是模糊的。尖銳的過渡將創建CG眼睛外觀。
我傾向於在Photoshop中在虹膜貼圖周圍創建一個圓形選區，將外緣變暗，這樣可以定義出虹膜的輪廓，但這應該是非常微妙的，而且在很大程度上取決於參考
Maya viewport: The sclera and caruncle geometries fit cleanly into the model, making sure to avoid clipping and large gaps.
Maya視口。鞏膜和角膜的幾何圖形乾淨利落地貼合在模型中，注意避免剪裁和大的縫隙。
①：Sclera Specularity IOR=1.37
No coat used in order to avoid unwanted strong reflections in the iris.Subsurface radius colour set to a very desaturated peach tone.Caustics ON
①：鞏膜鏡面反射率IOR = 1.37
未使用coat塗層以避免虹膜上發生不必要的強烈反射。Subsurface次表面半徑顏色設置為非常不飽和的桃紅色調
②：Caruncle Includes a transmission mask at its edge to blend into the sclera.
Shaded very much like shiny skin (IOR set to 1.4).
②：Caruncle在其邊緣包括透射遮罩，以融合到鞏膜中。
陰影非常像光澤的皮膚（IOR設置為1.4）。
③：Pupil A plain dark grey colour is used.
It has some specularity with a roughness of 0.65 and IOR of 1.4.
It should react with the light in a subtle way and not be completely black.
③：瞳孔採用普通的深灰色。
它有一些specularity鏡面反射，roughness粗糙度為0.65，IOR為1.4。
它應該與光線發生微妙的反應，而不是完全黑色。
④：Iris
Some SSS is used. Too much will eliminate bump effects. A very rough specular effect can be applied; none is used here.
④：虹膜
使用了一些SSS。太多會消除凹凸效果。可以使用非常粗糙的鏡面效果，這裡沒有使用。
⑤：Meniscus
The waterline is a piece of geo created only when the eyes’shape and positioning are finalised. I usually create this using quad draw in Maya.
A water preset is applied for the material.
You can achieve better effects with a bump map applied (not added yet).
⑤：半月板
水線是一塊只有當眼睛的形狀和位置最終確定後才創建的地理位置。我通常在Maya中使用quad draw創建這個。
將對材質應用水預設。
應用凹凸貼圖（尚未添加）可以獲得更好的效果。
Eyes Turntable
-GIF效果演示-
Skin Shading Texturing
皮膚著色貼圖
As mentioned in Part 1, the cross-polarised diffuse map was cleaned in Mari, removing hair and unwanted shadows picked up from the photogrammetry session.
I also worked in Photoshop to colour grade the diffuse map to better match the skin tone of the subject in the cross-polarised reference images. This took many iterations over the course of the look development process. Here is the final result:
正如在第一部分中提到的那樣，我在Mari中清理了cross-polarised交叉極化的diffuse map漫反射圖，去除了從攝影測量過程中拾取的毛髮和不需要的陰影。
我還在Photoshop中對漫反射圖進行調色，在交叉極化中更好地匹配受試者的膚色。在整個造型開發過程中，我經過了多次迭代。下面是最終的結果。
When I finalised the look of the displacement map, I exported a normal map from ZBrush and converted it into a cavity map in Photoshop.
I then overlaid this cavity map over the diffuse and set it to a very low opacity to give the subtle hint of skin pores that would correlate with the skin detail.
當我最終確定置換貼圖的外觀時，我從ZBrush導出了一個法線貼圖，並在Photoshop中將其轉換為一個cavity map。
然後，我將這個cavity map覆蓋在漫反射上，並將其設置為非常低的不透明度，以提供與皮膚細節相關的細微毛孔。
For this project, we wanted to go for a one-to-one likeness for the skin. Since the photogrammetry didn't provide me with a displacement map, / utilised the two colour maps (polarised and cross-polarised).
I subtracted the CP from the polarised image to reveal the specular only. This was made black and white with a levels and high-pass filter applied to essentially create a bump map・
在這個項目中，我們想為皮膚做一個1：1的相似度。由於攝影測量沒有提供displacement map位移圖，所以我利用了兩張彩色圖（(polarised偏光和cross-polarised交叉偏光）。
我從polarised image偏振圖像中減去了CP，僅顯示出specular鏡面反射。進行了黑白處理，並加上了levels調整圖層和high-pass filter高通濾鏡，基本上可以創建凹凸貼圖・
This bump map was then imported into ZBrush as an alpha and subsequently applied onto the surface of the model as a displacement map (on a layer).
Before applying, / subdivided the model from 7K polys to 29M. Which, after some testing, I felt would be sufficient to capture fine details.
然後將此凹凸貼圖作為Alpha導入到ZBrush中，隨後作為置換貼圖（在圖層上）應用到模型的表面。
在應用之前，/將模型從7K polys細分為29M。經過一些測試，我覺得這已經足夠捕捉到精細的細節了。
subtract
I then proceeded to create new layers to edit the displacement map. For example, I wasn't happy with the quality of the cheek detail, so I smoothed it out and used ZBrush's surface noise feature to populate the cheek area with Texturing XYZ's tileable micro displacement cheek map (right).
然後，我繼續創建新的圖層來編輯置換貼圖。例如，我對臉頰細節的質量不滿意，所以我將其smoothed平滑化，並使用ZBrush的surface noise表面噪波功能，通過紋理化XYZ的可平鋪微位移臉頰貼圖填充了臉頰區域（右）。
（Layers of skin detailing in ZBrush）
The displacement map was then exported out of ZBrush for Arnold at8K resolution using these settings.
I chose to export the map and base at subdivision 4 since/would be testing offline renders in Arnold.
The higher you export，the more exact the displacement will appear to the detail in your ZBrush model.
然後，使用這些設置將置換貼圖導出到ZBrush中，以獲得Arnold at8K分辨率。
我選擇導出第4分區的地圖和底圖，因為/將在Arnold中測試脫機渲染。
導出得越高，ZBrush模型中的細節顯示的位移就越精確。
The displacement map was then brought into Nuke to split the displacement out into displacement and micro displacement.
Using a high-pass node set-up. I was able to capture the high-frequency details of the map.The original displacement was also blurred.This would enable me to add the maps together and have more control over how strong the micro details appear.I would also be able to paint a mask and reduce the micro-detail in certain areas，if lso wish.
然後將displacement map置換（位移）貼圖導入Nuke中，將位移分成了位移和微位移。
使用high-pass node高通節點的設置。我能夠捕捉到地圖上的高頻細節。
這樣一來，我就可以把原來的位移也模糊化了，這樣一來，我就可以把這些地圖加在一起，對微觀細節的出現有了更多的控制。
如果我願意的話，我還可以畫一個蒙版，減少某些區域的微觀細節。
（注：原圖清晰度就是這樣看不清，PS裡銳化了下，只能湊合了喲）
Displacement Split Process
Close-up of the cheek and under-eye area.
臉頰和眼下區域的特寫。
I used the same method for the bump map to create the specular map.subtracting the two maps reveals only the specularity of the skin，which I could clean up and grade to provide a specular map.
我對bump map凹凸貼圖使用了相同的方法來創建specular map高光貼圖。減去這兩個貼圖只顯示皮膚的高光性，我可以清理和分級以提供高光貼圖。
l inverted the specular map to create a base for the roughness.Again， this was colour graded along with some hand-painting to achieve the final result.
The remaining colour correction would be done inside of Arnold to get the right look for the skin.
A subsurface weight map was also painted.The map is essentially an off-white with the thinner areas of the head such as the nose，ears，eyelids and lips were painted more white.
我將鏡面圖反相，為粗糙度打下基礎，再一次進行顏色分級，再加上一些手繪，最後的效果就出來了。
剩餘的顏色校正將在阿諾德內部進行，以獲得正確的皮膚外觀。
此外，還繪製了一張次表層重量圖，該圖基本上是灰白色的，頭部較薄的部位如鼻子、耳朵、眼皮、嘴唇等部位被塗成了白色。
-GIF效果演示-
（Single Softbox Light Turntable 1）
（單柔光箱燈-旋轉1）
l used Arnold's aiStandardSurface shader for the skin and subsequently plugged in my maps.In this instance， l am using the ACES colour space， which allows more control over the whites.Automatically， they are clamped at around 0. 82 meaning I can push this value to get brighter whites in the render.
This is the reason for neglecting the coat map in the skin shader， since l could get everything I needed from the specular section.
我為皮膚使用了Arnold的aiStandardSurface著色器，然後插入了我的maps貼圖。在這種情況下，我使用了ACES色彩空間，可以更好地控制白色。自動將它們固定在0.82左右，表示我可以按下此按鈕值以在渲染中獲得更亮的白色。
這就是我忽略了皮膚著色器中的coat map塗層貼圖的原因，因為我可以從specular高光部分獲得我所需的一切。
上圖補充
The red channel of the texture map is plugged into the welght attribute for it to function property.
For physicaly accurate resutts, the lOR for the skin is loft at,1.4.
紋理貼圖的紅色通道被插入到welght屬性中，以使其發揮作用。
為了獲得物理上的精準還原，皮膚的LOR為1.4。
A generic peach colour is used for the radius.The ACES colour space makes it appear darker here.
The scale of my scane is in metres which is why the SSS scale is>1.The value should be 1/10 of this.
半徑使用通用的桃紅色.ACES顏色空間使其在此處顯得更暗。
我的掃描儀比例尺以米為單位，這就是SSS比例尺> 1的原因。該值應為此值的1/10。
Every texture map is connected to an aiColourCorrect node for me to grade the maps inside of the renderer and get realtime feedback as It weak the values.The final look of the textures are demonstrated below.Note，the difference between the maps on the previous page.
每個紋理貼圖都連接到aiColourCorrect節點，以對渲染器內部的貼圖進行分級，並獲得實時反饋，因為它削弱了這些值。紋理的最終外觀如下所示。請注意，上一頁中的貼圖之間的差異
-GIF效果演示-
（Point Light Lighting Animation）
(點光照明動畫)
-GIF效果演示-
（Single Softbox Light Turntable 2）
（單柔光箱燈-旋轉2）
For the displacement， l used a PlusMinusAverage node to add both the micro displacement and base displacement maps together.
Each of these maps was hooked up to an aiRange node before being added together.
對於位移，我使用了一個PlusMinusAverage節點將微位移和基數位移圖加在一起。
每張地圖都被連接到一個aiRange節點上，然後再一起添加。
This way， I could control the displacement intensity in the‘Output Max'attribute highlighted below.
這樣，我可以在下面突出顯示的“Output Max”屬性中控制置換強度。
When working on the skin， I made sure to test the skin material under various lighting condtions.I had a handful of high-quality references comprising of a single and double softbox light， which was my main lighting setup.This way， I could attempt to match my renders with the photographs.
But it's always useful to have a skydome light in your scene to do some HDRI tests of indoor and outdoor environments.
The model was imported into May a from ZBrush at subdivision level 4as was the displacement.For the purpose of these offline renders I can afford to export high-res geometry.This also allows me to maximise the level of detail the geometry displaces so it better resembles the sculpt inside of ZBrush.
在製作皮膚的時候，我確保在不同的光照條件下測試皮膚材料，我有一些高質量的參考資料包括單柔光箱和雙柔光箱燈，這是我的主要照明設置。這樣，我可以嘗試使我的渲染與照片匹配。
但是，在您的場景中使用天穹燈對室內和室外環境進行一些HDRI測試總是有用的。
該模型是從ZBrush細分級別4導入Maya的。為了這些脫機渲染的目的，我可以輸出高分辨率的幾何體。這也允許我最大化幾何體置換的細節級別，使其更像ZBrush內部的雕刻。
（Exterior and Interior HDRI's. Sourced from HDRI Haven.）
All renders are rendered out in P3-D60(ACES) colourspace. For the ACESworkflow， all of the texture maps are converted to 32-bit EXR files.
All weight maps are set to colourspace：Utility(RAW) whereas colour maps are set to ACES cg.
All texture maps in regards to the skin are 8192x 8192.
The final skin shader was mixed with another standard surface shader for the make-upon her upper eyelid. A weight map was painted of the upper eyelid and connected to the ‘Mix’ attribute allowing me to create this effect separately from the skin shader and better match the reference image.
Note， the eyebrows and eyelashes are the only grooms presents of ar since all facial grooms will be revealed in the next part. With that said， peach fuzz and facial hairs do enhance the look and feel of the skin， and overall realism. So while this represents the final skin material it does not represent the final look of the skin.
The render was colour matched to the reference image in Nuke.
On the right are the specular， wireframe and lighting passes.
所有渲染均以P3-D60（ACES）色彩空間渲染。對於ACESworkflow，所有紋理貼圖都轉換為32位EXR文件。
所有權重圖均設置為colourspace：Utility（RAW），而顏色圖均設置為ACES cg。
關於皮膚的所有紋理貼圖均為8192x 8192。
將最終的皮膚著色器與另一個標準表面著色器混合在一起，以在她的上眼瞼上進行化妝。繪製了上眼瞼的權重圖，並將其連接到“ Mix”屬性，使我可以與皮膚著色器分開創建此效果，並更好地匹配參考圖像。
注意，眉毛和睫毛是現在唯一的毛髮，因為所有的面部毛髮都將在下一部分中展示。也就是說，桃子絨毛和麵部毛髮確實增強了皮膚，整體真實感。因此，雖然這代表了最終的皮膚材質，但並不代表皮膚的最終外觀。
渲染圖的顏色與Nuke中的參考圖片進行了匹配
右邊是鏡面反射、線框和燈光過程。
（3 Point Light (with facial groom)）
-END-
皮膚部分到這裡就結束了。
下期內容強烈推薦！！！
內容為毛髮，包含眉毛、臉部耳朵部位的桃子絨毛、以及頭髮！
翻譯的文章在版權上來說是不屬於原創的， 因此我們沒有做原創標註！轉載請註明出處！
下期再見~❥(^_-)
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關鍵字: 嘉兒 displacement ZBrush
