Create a stylized character with Pixar’s Renderman & ZBrush
In this tutorial, I will show you the steps to make a stylized character from modeling to compositing based on a concept art, using PureRef for the references, Maya and ZBrush for modeling, Substance Painter for texturing, Renderman for look dev and lighting, and Da Vinci Resolve for compositing.
Look for a concept that you like, after that the first step is to gather as much reference as you need. Search for everything that will help you understand better the concept. In this case, I looked for skeleton references and the objects the “King” is wearing (clothes, sword, metals, feathers) and more ref for the owl, topology, and hands position.
Now we start playing with the concept, you have to study the concept and start blocking shapes to spot as soon as possible perspective mistakes or troubles that you might find in later steps. I used Maya, but you can do it in any 3D software – for this one I had to put a camera, pick a focal length, and start modeling and moving shapes around to try to fit the concept. It was tricky to get all the parts working; flying bones, one shoulder only, and to match the perspective of the concept. Don’t spend too much time refining shapes in the blocking step, you will do that later in ZBrush.
Sculpting part 1
This is where you will be refining the shapes that you made and fixing proportions and adding some details where you need. For now, just focus on your proportions, use the Move brush, and build up brushes to find the shapes from your concept. Use Goz to see how the overall model is looking through your Maya camera. Do this step until you are happy with the overall shape of your model.
Retopology and UVs
Even if your character is not going to be animated, it is a good practice to make a good retopology, not only will it help you for future projects, it will help to get better and faster UVs. You can start decimating your sculpted model from ZBrush, and send it to Maya, then after this just check for references, and start using the tools for it. Nowadays every software has a good toolset for retopology. For Maya it is the Quad draw tool.
After you finish doing your retopology, start doing your UVs. It’s recommended to use UDIMs, so your texture-look dev process will be faster. When you are using UDIM it’s good to separate your UV tiles based on materials, and try to cut seams where the camera can’t reach, and sometimes your displacement maps will get funky artifacts on those seams, so it’s good to avoid as much as possible those mistakes.
Sculpting part 2
Okay, now that we have our topology and UVs ready for our model, we are going to export it to ZBrush and finish the finer details, scratches, slashes, and other stuff you find interesting to add. I love to use the orb brushes from Michael Vicente, for those details. For the Owl I used a Fur Brushes pack from Jarred Everson.
After this, use the multimap exporter to create your normal, displacement maps and other extra maps you will need from ZBrush. One thing I like to do is to export a normal map at a higher level of subdivision because the displacement will get almost all your details, so your normal map will get the finer details only.
After you baked everything in Substance Painter, start creating the hand-painted feel from the concept. Take advantage of some of the default Photoshop brushes inside substance painter to give it that hand-painted look, you also can import custom Photoshop brushes to give an extra kick to it. And don’t forget to have fun painting all the textures.
Export the textures from Substance Painter and start doing your look dev. I used Pixar Renderman for this project, so I created a dome light and place a HDRI with similar colors to the concept, and I started to play with the materials. I also added all the grooming, beard, grass, feathers, and hair.
For this step I wanted to achieve a special look to it, so I researched a lot of Pixar materials, and found an interesting article on how they made the food in Ratatouille, from that article it came the idea to turn on a single scatter effect in every material, that way it gave the look I wanted. All Renderman materials have a single scatter lobe that you can use for this and it worked like a charm. I just painted a gray texture that drives the amount of scatter where I need it and plugged it to the gain attribute.
Now that the look dev is ready, place lights to bring life to the scene. In my case, I like to use a lot of rim lights to lift the edges of the object that the main light can’t reach, and depending on the color of the materials, I change the light color to rise or lower the values of that material.
All this process must be done by watching the concept closely, so you don’t lose the general value of it and adding lights and stuff that will improve it. When you are happy with your results, just add the AOVs you will need for compositing. One important AOV I needed to add was the single scatter, so I could play those colors with the cryptomatte in Da Vinci Resolve
For this step, just take the AOVs you did from Renderman and tweak as much as you like to get the result you desire. I used Fusion inside Da Vinci Resolve to make the compositing of the shot, it works the same as Nuke. What I did was to take all the AOVs, and start doing some color correction using cryptomatte, and adding the common stuff. Vignette, Zdepth, and so on. I played a lot with the single scatter AOV, that was the core of the look of what I was looking for.
Top Tip 1 - Export ID Colors from ZBrush
When you are in ZBrush make a texture map from your polygroups. This is useful to use as an ID map in Substance Painter to mask things. You can make your polygroups from UVs, or other settings you pick.
Top Tip 2 - Paint in Substance with Full Detail
Export from ZBrush a decimated model with the UVs to Substance Painter, so you can paint and apply masks that grabs most of the details you did in ZBrush. This works because in Renderman you are going to use the Displacement map to bring most of the details.
Top Tip 3 - Metalness to Disney Pixar
For the metalness to work in Pixar Renderman 23 you have to plug it in the Disney Pixar Material, that’s why it’s important in the UVs to put all the metal in one tile.