It’s so fluffy!

When we voted for a cover, the newsroom unanimously choose the baby cheetah – besides its undeniable fluffiness it is also one of our favorite stills this year. Reason enough to ask a couple of questions.
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Yuriy Dulich, a Character Artist and Groom TD from Kiev, Ukraine, tells us about being a CG groomer. He currently works at Image Pictures as Lead Groom TD and takes part in the creation of Ukrainian animation feature films. Besides grooming, his duties include the adjustment and simulation of the dynamics of hair, fur and feathers, interaction with the departments of animation, artists, visualization and the character setup department, development of control systems for feather characters and characters with long hair. You can check out his work at www.yuriydulich.com.

DP: What was your inspiration for the baby cheetah?
Yuriy Dulich: No one can create better than nature. I find inspiration in the world around us – concerning the baby Cheetah, I was always charmed by such graceful animals and how nature made them evolve into practically perfect predators, though their population decreases and they might disappear for good very soon. Therefore, one of the reasons for creating the baby in CG was to depict how they differ from the adult specimen, and how nature helps them with camouflage to enhance their survival. And probably for a future digital catalog of animals, who knows, maybe someone will create it in the future.

DP: Could you describe your pipeline?
Yuriy Dulich: In the beginning, I collect a lot of references with different perspectives, even some parts of the body and in different lighting. For this purpose I use google.com and flickr.com. Also, before starting the modeling, I watch many video references, documentary films by BBC and National Geographic, private video and feature films. If there is a possibility to see what I need in a museum or zoo, I go there. It gives me a feeling for the character or animal, I learn its peculiarities and figure out its components, as if I could see it live. For the baby cheetah, I collected about 250 photo references in total, which showed almost all details from eyelid creases to the direction of hair growth. The technical core of my pipeline is Maya, where I build blocking of the future character from primitives. Then I transfer it to ZBrush, make a complete sculpting in Dynamesh mode and change proportions if there is a need.
When sculpting the animals with hair upon the references, there is a big desire to build them including the volume of fur. In that case, this mesh can be used as a shell during grooming, but I create the principal body as in real life. References of the skeleton and muscles help a lot with this. When sculpting the areas covered with fur, you should mind that a fur layer smooths the surface, so in this areas I work only at the muscle level without detailing any pores or folds. I detail only the areas where the skin is open or only slightly covered by hair. When I am satisfied with the detailed sculpting, I make a retopology in Topogun. Then there is the UV mapping stage, it does not have any tricks – I place the character on several UV tiles (UDIM) – the more tiles, the less texture size can be used. And then I begin with the most interesting and meticulous stage – grooming!
I create basic textures for localization of the necessary parts of fur in advance and layer by layer grow the fur. For texturing at all stages I use Mari. Along with the grooming I prepare the textures for shading and set up the shader. Here I use a standard Arnold shader (Core 5.x.x) – aiStandartHair. To achieve a photorealistic effect for all characters, I use a melanin-centric shading model. When I have the necessary result and the grooming will not be changed anymore, I create an animation rig, because I often change the basic geometry at the grooming stage. For that, I use the Advanced Skeleton auto-rig system. The positioning of the character can become a real pain for me and sometimes this process can take several days. This is why I separately select from the total collection of references separate references for poses. Adjustment of lighting is individual and as a rule, I look for the lighting references and adjust several types of lighting along with optimization of the render settings, and also create the necessary render passes for the future post-processing. I use Kick for final rendering and make post-processing in Fusion.

Yeti node network of primary fur
Yeti node network of primary fur

DP: The little one is quite furry with both normal fur and the long kitten hairs, which are common on cheetahs. How did you create them?
Yuriy Dulich: Actually, it is not difficult. The most important part is to analyze references and understand the structural layers of fur of the animal, their number and structure of fur in each layer. The cheetah cub has 8 layers of primary fur, 3 layers in mane and also a layer of mustaches. The search for the proper balance of the thickness and volume of fur is a very important factor. For example, felines have a difficult shape of hair, and if you replicate it in CG, it will be a plus. I get the softness of the fur as well as its stiffness using a balance of shader and thickness of hairs of the fur.

Arnold shading of primary fur
Arnold shading of primary fur

DP: If someone would like to get the same hair effect, what would you recommend?
Yuriy Dulich: Analysis of references and attention to details, and do not try to make everything at the same time – do everything layer by layer and don‘t forget about the density of each layer. Do not complicate your working process with the creation of new node connections – make a basic network and develop it by adding the necessary attributes and nodes. Remember, you will need to render it, so clean it from all excessive and unused features. Optimize the number and resolution of textures – which is why I use RGBA masks.

Light rig
Light rig

DP: If you’d have to start over, what would you change about your approach?
Yuriy Dulich: We have a proverb: “Danger foreseen is half avoided.” In reality, mistakes in the work process are valuable experiences because we learn a lot by solving problems. I think that ability to finish the project is more important than to start it – the ability to say to yourself: “it’s enough”, and not to postpone it by saying: “I will correct something else a little bit”. I had many situations when I did not realize what the final image would look like and very often went around in circles because of that, and there was a risk to become tired of the project. You need to be able to evaluate the situation and avoid burning out. But if you catch yourself thinking that this is the moment, I will give you a simple advice – take a break for several days, do your routine work, regular issues, talk with your family, forget about the project for some time. Believe me, the next time you look at the project, you will have both answers and solutions to problems.

DP: Did you compare your hair-tool to other tools?
Yuriy Dulich: Yes, I used Shave and a Haircut and early versions of X-Gen before Yeti. As for me, Yeti has a very big advantage – its nodality, which allows me to create different versions of the layer of hair and to switch or animate them quickly. It is more flexible due to scripting. Appropriate work with cash allows me to reuse it in the node tree, for example for feathers. And what about placing herbs or garbage in the fur or hair? No problem! There is much more. I managed to be beta-tester of the versions 2.2 and 3.0, and I liked very much that the developers listened to the wishes of the users and tried to keep the product at a high level – not as they see it, but as the Yeti community wants it.

DP: Are there any plug-ins you use in your pipeline?
Yuriy Dulich: Over the many years of work I have adjusted my pipeline at quite a high level. Yes, there are some tasks which do not completely fit it and then I either write a script myself or buy a ready-made solution. If I see an interesting software, then I create a character to check it out in a real project and decide if I need it in my pipeline. For grooming, I often use my two small scripts (yetiGuideAtrr and convCurv2GuideWind) and modified SeExprEditor by Evgeny Grebennikov (Besha1).

DP: What is your next project?
Yuriy Dulich: I adore characters and animals and I also like the fantasy world of Tolkien. This is why I decided that for the next several years I will work with the characters and bestiary of „The Silmarillion“ – to create Carcharoth, wonderful Huan, crawling Glaurung and other great characters of Tolkien. Along with it, I want to make a series of lessons on grooming and my work with Yeti to give this knowledge to those who need it.

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