使用 Maya、ZBrush 和 XGen 创建极其逼真的肖像
本帖最后由 孟中子 于 2023-9-14 11:36 编辑Hadi Karimi shared the workflow behind the model of his friend Clara, showed how the hair was done using XGen, and explained why historical figures are challenging to recreate.
Hadi Karimi分享了他的朋友Clara模型背后的工作流程，展示了如何使用XGen完成头发，并解释了为什么历史人物很难重现。
Introduction
I'm Hadi Karimi and I’m a freelance CG artist from Iran. I’ve been a digital artist for about 15 years. My journey started with learning Photoshop and using a very cheap digital pen to teach myself digital painting. Before that, I used to draw portraits, but it was more like a hobby. It was after learning digital art that I started to take it more seriously and learn different software until one day I stumbled upon Cinema 4D which was the first 3D software I learned.
In the beginning, I was just making abstract art and simple compositions, but after a few years, I added ZBrush and Maya to my arsenal and was able to utilize the years of experience that I had gained from my journey as a painter.
The projects I have worked on so far are mostly likenesses of celebrities and some historical figures.
介绍
我是Hadi Karimi，是来自伊朗的自由CG艺术家。我做数字艺术家已经有15年了。 我的旅程始于学习Photoshop，并使用非常便宜的数字笔自学数字绘画。在此之前，我曾经画过肖像，但这更像是一种爱好。在学习了数字艺术之后，我开始更加认真地对待它并学习不同的软件，直到有一天我偶然发现了Cinema 4D，这是我学到的第一个3D软件。
一开始，我只是在制作抽象艺术和简单的构图，但几年后，我将ZBrush和Maya添加到我的武器库中，并能够利用我作为画家的旅程中获得的多年经验。
到目前为止，我参与的项目大多是名人和一些历史人物的肖像。
I think my most challenging works so far have been a series of portraits during which I reconstructed some historical figures’ faces. It’s easy to find references when working on a modern celebrity portrait, but for historical subjects, it’s an entirely different process. Especially for those who lived before the invention of the camera, the only references available are paintings, face masks, and sometimes only descriptions of their appearances.
The ones I’m most proud of are my portraits of Chopin and Beethoven.
我认为到目前为止，我最具挑战性的作品是一系列肖像画，在此期间我重建了一些历史人物的面孔。在制作现代名人肖像时很容易找到参考资料，但对于历史主题来说，这是一个完全不同的过程。特别是对于那些生活在相机发明之前的人来说，唯一可用的参考资料是油画、面模，有时只是对他们外表的描述。
我最引以为豪的是肖邦和贝多芬的肖像。
The Eminem model was one of the first 3D likenesses I modeled, but I recently did a rework. I think he has a very unique facial bone structure.
The Christian Bale model was also a very interesting and tricky subject. The thing about actors is that they all have expressive faces, it takes a lot of practice and experience to fully capture the countenance.
埃米纳姆模型是我建模的第一批3D模型之一，但我最近做了一个返工。我认为他有一个非常独特的面部骨骼结构。
克里斯蒂安·贝尔模型也是一个非常有趣和棘手的主题。做为演员的他们都有富有表现力的面孔，需要大量的练习和经验才能完全捕捉到面容。
Clara
I was kind of bored of working on the faces of famous people and wanted to try something new. It’s not as easy as you might think to ask people around you to be your model, understandably, not everybody is a fan and/or has the stomach for a digital version of their face to be presented to thousands of strangers on the internet. But Clara is also a 3D artist herself and we had worked on a couple of projects together. Luckily, she was intrigued to be a model and seems to be happy with the result too.
A photoshoot of the subject from different angles would have been really helpful, but since we live in different countries, that wasn’t feasible. So instead, I tried my best to study an archive of her photos that were already available in order to capture the likeness.
克拉拉
我对画名人的脸有点厌倦了，想尝试一些新的东西。让身边的人做你的模特并不像你想象的那么容易，可以理解的是，并不是每个人都是你的粉丝，或者不是每个人都有兴趣把自己的数字版脸在互联网上展示给成千上万的陌生人。但Clara自己也是一名3D艺术家，我们曾合作过几个项目。幸运的是，她对成为一名模特很感兴趣，似乎对结果也很满意。
从不同的角度拍摄主题会很有帮助，但由于我们生活在不同的国家，这是不可行的。所以，为了捕捉到她的相似之处，我尽了最大的努力去研究她已有的照片档案。
Head
I usually start my likenesses on a base mesh so I have a clean and ready model from the get-go. My main tool for sculpting has always been ZBrush, where I import the base mesh and keep tweaking it to match the proportions of my reference photos. The texturing process also happens all inside ZBrush. I used PolyPaint to paint the albedo map and used Geometry HD to sculpt the displacement map and transfer all the skin details from the high poly mesh to the low poly model for the final render.
头
我通常在基础网格上开始我的肖像，这样我从一开始就有一个干净且准备好的模型。我的主要雕刻工具一直是ZBrush，我导入基础网格并不断调整它以匹配我的参考照片的比例。纹理过程也全部发生在ZBrush内部。我使用PolyPaint绘制了反照率贴图，并使用Geometry HD雕刻了置换贴图，并将所有皮肤细节从高多边形网格体转移到低多边形模型以进行最终渲染。
The hair was groomed using XGen inside Maya. XGen is such a versatile hair system that makes any hairstyle not only possible but also enjoyable to model and groom. For this project, I had five different XGen descriptions. One for the long hair which was the most time-consuming part of the hair grooming process. I also have a separate description for the sideburns and the transition hair around the hairline.
头发是用玛雅内部的XGen做的。XGen 是一种多功能的发型系统，不仅使任何发型成为可能，而且使模特和修饰都令人愉快。对于这个项目，我有五个不同的XGen描述。一个用于长发，这是头发梳理过程中最耗时的部分。我对鬓角和发际线周围的过渡毛也有单独的描述。
There is a description for the eyebrows which was also very tricky to do! It could spoil the whole likeness if not done right. The lower and upper eyelashes also each have their own separate descriptions, the difference here is that I added and groomed all the strands one by one since it’s not easy to get the nuances of an individual’s lashes simply by randomly generating hair across the surface. This method clearly takes more time but I think it’s worth it in the end.
眉毛有一个描述，也很难做到！如果做得不好，它可能会破坏整个肖像。下睫毛和上睫毛也有自己单独的描述，这里的区别在于我一一添加和修饰了所有的睫毛，因为仅仅通过随机生成头发来获得个人睫毛的细微差别并不容易表现。这种方法显然需要更多时间，但我认为最终是值得的。
OutfitI
have a collection of base meshes for different outfits that I usually model my characters’ clothes on top of. The biggest challenge for the clothes was getting the folds and wrinkles to look natural. Modeling the details for clothes is very different compared to the face and human skin. Each fabric and material have its own physical properties that are essential to know in order to have a better understanding of how they react and take form under stress.
衣服
我有一系列不同服装的基础网格，我通常会在上面为角色的衣服建模。衣服面临的最大挑战是让褶皱和皱纹看起来自然。与面部和人体皮肤相比，衣服的细节建模非常不同。每种织物和材料都有自己的物理特性，为了更好地了解它们在压力下的反应和形成，必须了解这些特性。
Pose
I actually always sculpt my characters in their natural poses, then add a basic rig inside Maya to be able to pose them for the final composition. I just think it makes it unnecessarily complicated to sculpt a character in a pose, especially when you’re working on someone’s likeness and have to constantly compare the model to reference photos from different angles.
After posing the character using the rig, I added a few blend shapes to fix and readjust some areas around the eyes and neck.
Texturing
Most of the time I only use the aiStandardSurface for Arnold since it’s always so easy to set up. For the face, I used five different maps: albedo, specular, roughness, coat, and displacement.
姿势
实际上，我总是以自然的姿势雕刻我的角色，然后在Maya中添加一个基本的rig，以便能够为最终的构图摆姿势。我只是认为这使得在一个姿势中塑造一个角色变得不必要的复杂，特别是当你在制作某人的肖像时，必须不断地将模型与不同角度的参考照片进行比较。
在使用钻机摆出角色姿势后，我添加了一些混合形状来修复和重新调整眼睛和脖子周围的一些区域。
变形
大多数时候，我只使用阿诺德的aiStandardSurface，因为它总是很容易设置。对于脸部，我使用了五种不同的贴图:反照贴图、高光、粗糙度、涂层和置换贴图。
For the eyes, there are two separate objects, one for the iris and one for the cornea and sclera. And they each have an albedo and a displacement map.
对于眼睛，有两个单独的对象，一个虹膜和角膜和巩膜。 和他们每个人都有一个反照贴图和一个置换贴图。
For the sweater, I used a tileable knit texture to cover the whole surface and on top of that had another displacement map to add the fine details and wrinkles that I had sculpted in ZBrush.
Lighting
The images below show my lighting setup. It’s a combination of three area lights in quad mode. Here you can see the intensity and temperature for each light that mix of all three results in the final render.
对于毛衣，我使用了一个平铺的编织纹理来覆盖整个表面，在此之上还有另一个位移贴图来添加我在ZBrush中雕刻的精细细节和皱纹。
灯光
下图是我的照明设置。 这是一个结合三个区域中的灯光四模式。 在这里你可以看到的强度和温度为每个光的混合所有三个结果在最终渲染。
I think each step is equally important if you want to achieve a true photorealistic render. For example, you can’t hide a mediocre sculpt behind high-quality textures or fix a poorly done hair with good lighting, vice versa a bad lighting setup can make the render look boring even if the model is well done.
For the post-processing, I just added a LUT in Photoshop to make the colors more vivid.
我认为每个步骤同样重要的如果你想要实现一个真正的真实感的渲染。 例如，你不能用高质量的纹理隐藏一个平庸的雕塑，或者用好的照明修复一个做得不好的头发，反之亦然，一个糟糕的照明设置会使渲染看起来很差，即使模型做得很好。
至于后期处理，我只是在Photoshop中添加了LUT，使颜色更加生动。
I believe the whole process took about two months. Four weeks to finish the likeness, one week to finish all the textures, and a couple of weeks for the hair grooming. There are always technical challenges along the way but the predominant obstacles that you have to overcome are psychological. When you spent so much time on a piece, you can’t help but feel burned out and overwhelmed at some point and that’s where self-doubt kicks in and you keep asking yourself is this even going to work out in the end or am I wasting my time. And the only way to quell this sort of feeling is to keep working methodically until you have something that you can be proud of.
Another big challenge is that when someone trusts me to make a good portrait of them, I just don’t want to disappoint and sometimes that can also be anxiety-inducing.
But honestly, with all these hurdles, I think I’ve learned how to manage my emotions and simply enjoy the ride.
我相信整个过程花了大约两个月。 四个星期完成的肖像，一个星期完成所有的纹理，几个星期的头发梳理。 总有一些技术挑战，但主要的障碍，你必须要克服心理。 当你花了如此多的时间在一块，你不能不感到焚毁和不堪重负，在某一点，这就是自我怀疑的在踢你一直在问自己这是甚至要在工作结束或我浪费我的时间。 而唯一的办法，以平息这样的感觉，以保持工作有条不紊地直到你拥有的东西，你可以感到骄傲。
我想整个过程大概花了两个月。4周时间完成造型，1周时间完成所有纹理，再花几周时间梳理头发。一路上总会遇到技术上的挑战，但你必须克服的主要障碍是心理上的。当你花了这么多时间在一件作品上，你会忍不住在某些时候感到精疲力竭和不知所措，这就是自我怀疑的开始，你不断问自己这最终会成功吗，还是我在浪费时间。以平息这样的感觉，以保持工作有条不紊地直到你拥有的东西，你可以感到骄傲。
另一个巨大的挑战是，当有人相信我能给他们拍出一张好照片时，我只是不想让他们失望，有时这也会引起焦虑。
但老实说，面对所有这些障碍，我想我已经学会了如何管理自己的情绪，简单地享受这段旅程。
Advice for ArtistsI have some tutorials beginner artists can use on my YouTube channel. But I think right now everything is so different than when I started. There’s so much distraction going on. Like NFTs, AI, etc., that can be great if you know how to properly utilize and take advantage of but at the same time could be detrimental in the long run.
“Why would I spend years mastering my craft when people are making easy money selling a bunch of lazy uninspiring art? Should I even become an artist when everything is going to be AI-generated in a few years?” are the sort of questions that the younger generation might be asking right now.
And honestly, nobody has a clear answer and knows what the industry would be like in ten or even five years. But at the end of the day, you have to ask yourself if your fears are bigger than your dreams. If the answer is no then you’ll find a way to shine.
Hadi Karimi, CG ArtistInterview conducted by Gloria Levine给艺术家的建议我在我的YouTube频道上有一些新手艺术家可以使用的教程。但我觉得现在一切都和我刚开始的时候不一样了。有太多的事情让人分心。就像nft、人工智能等一样，如果你知道如何正确利用和利用，这可能是件好事，但从长远来看，这可能是有害的。
“为什么我要花几年时间掌握我的手艺，而人们却可以通过出售一堆懒惰的、毫无灵感的艺术品轻松赚钱?几年后，当一切都将由人工智能生成时，我还应该成为一名艺术家吗?是年轻一代现在可能会问的问题。
老实说，没有人有一个明确的答案，也没有人知道这个行业在10年甚至5年后会是什么样子。但在一天结束的时候，你必须问问自己，你的恐惧是否比你的梦想更大。如果答案是否定的，那么你会找到一种闪耀的方式。
Hadi Karimi, CG艺术家
采访由Gloria Levine进行
使用Maya、ZBrush和XGen可以创建极其逼真的肖像。Hadi Karimi分享了他朋友Clara模型的工作流程，展示了如何使用XGen制作头发，并解释了为什么历史人物很难重现。
Advice for Artists艺术家的建议：我在我的YouTube频道上有一些新手艺术家可以使用的教程。但我觉得现在一切都和我刚开始的时候不一样了。有太多的事情让人分心，比如NFT、AI等等，如果你知道如何正确利用和利益最大化，这可能是好事，但从长远来看可能也会有害。
“为什么我要花几年时间掌握我的技艺，而人们却可以通过出售一堆懒惰的、毫无灵感的艺术品轻松赚钱？几年后，当一切都将由人工智能生成时，我还应该成为一名艺术家吗？”这可能是年轻一代现在会问的问题。
老实说，没有人有一个明确的答案，也没有人知道这个行业在10年甚至5年后会是什么样子。但在一天结束的时候，你必须问问自己，你的恐惧是否比你的梦想更大。如果答案是否定的，那么你会找到一种闪耀的方式。
Hadi Karimi, CG艺术家采访由Gloria Levine进行。
——微元素 × GPT，助力游戏开发，CG创作的无限可能！
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