Making a School Girl with Katana in Substance 3D Painter and ZBrush

Introduction

My name is Gina Jeon, I studied cartoons and animation in Korea, and I currently work in the game industry in the United States. I’ve been working for Crystal Dynamics as a Character Artist and participated in Marvel’s Avengers and other projects.

Inspiration and References

For the School Girl with Katana project, I initially intended to study hair card workflow using XGen to generate base textures. Then I thought it would be great to create a full character, so I decided to make a young girl with a Japanese-style school uniform and a blade. I was inspired by the animation Blood: The Last Vampire, a story of a high school girl with katana killing creatures. I got the keywords ‘school uniform’ and ‘katana’ from the animation and altered the rest.

Face and Hair

Before starting, I gathered as many reference photos as possible. It was especially important because I didn’t have a concept piece of art to start from. Then, I started sculpting the face. When sculpting a face, I usually use a low subdivision level until I make the main shape correct before getting into details. Besides, I found that the lighting in ZBrush can be deceiving sometimes, so it’s always a good idea to import the head to a rendering engine (Marmoset in my case) to check the facial shape under different lighting conditions.

Once I felt satisfied with the main shape, I created layers in ZBrush and put skin details using displacement maps from texturing XYZ. I used the ZWrap plugin to warp flat textures to fit the face. When applying displacement maps to the face, I made separate ZBrush layers for the R, G, and B channels since each channel of the XYZ Displacement Map contains different information. That way, it’s easy to adjust the layer intensities and mix the channels to get the desired look. After that, I added additional skin details using alpha brushes and hand-sculpting. Albedo Map was created in a similar manner, with adjustments for skin details and make-up in Photoshop and Substance 3D Designer. I added freckles, skin imperfections, and eyebrow details.

Hair card textures were created in Maya XGen. I used interactive groom splines to create hair guide splines and generated hair through the splines. I made several hair strips that I could use for hair creation and rendered base Albedo, Alpha, Normal, and AO Maps using Arnold renderer in Maya to use them as hair card textures. Then, I placed the cards manually onto the head. I went back and forth in Marmoset to check the hairstyle in the rendering engine because it sometimes reveals the area that needs fixing. Hair creation is a slow process that requires patience.

Eye meshes were made of several layers. First, I made the base eyeball mesh, then I made another layer for the sclera to mimic the real eyeball shape. After that, I added a tear line mesh following the curve of the eye openings so that it could make a slight wet line when the light hits the eyes. I also made a separate eye caruncle mesh to get better control of Color and Specular. I applied glass materials to the sclera and the tear line because they had to be transparent. For the eyeballs and caruncle, I used regular materials with a bit of SubSurface Scattering value.

Clothes

The school uniform base meshes were initially created in Marvelous Designer. When creating clothing, having solid sewing patterns as a reference saves from lots of guessing work when draping clothing in Marvelous Designer. I started with a T-posed base mesh to use as an avatar in order to drape the clothes to get the basic shape done. Then I posed the body mesh and updated the avatar, to generate natural fold logic that conforms with the posed body.

The next step was to take the asset to ZBrush for sculpting details. I reconstructed the mesh to get cleaner polygon structures suitable for sculpting because the mesh exported from Marvelous Designer isn't sometimes optimal for sculpting even after being quadrangulated. Keeping the base wrinkle created in Marvelous Designer, I added extra details and refined the shape using the move brush.

The rest of the outfit parts, katana, and accessories were created in Maya by poly modeling. I didn’t work on lots of details for the hard-surface meshes as in the image, because I could easily add details on Substance 3D Painter later. Fabric details, wear and tear, any cosmetic details were mostly done in SP. I liked how I could easily change the positions, add or remove cosmetic details in SP, compared to ZBrush where it’s cumbersome to modify the details after baking maps.

Retopology was done in Maya using Live Surface and Quad Draw functions. First, I imported high-resolution mesh and enabled Live Surface. Then I used Quad Draw to create polygons directly on the top. Quad Draw meshes were highlighted in blue, so I could easily distinguish the new mesh. I prefer this method because I don’t need to export meshes outside Maya and reimport them back.

After creating all the assets, I had to unwrap all the meshes. I used Maya’s default UV editor for laying out all the UVs and RoadKill UV for unwrapping. I found RoadKill gives pretty decent results with a single click compared to Maya’s unwrapping algorithm, and I could easily see stretched areas highlighted in red that needed more seam lines.

Texturing

Texturing was mostly done in Substance 3D Painter and Photoshop. First, I applied different materials in Maya to each section, so that I could toggle the visibility on/off in SP, then I made subfolders inside the SP layer to separate each material. I usually start by applying base materials first, with base color and roughness values, then I add tone variations, wear and tear, and dirt layers on the top. 

For this project, I added another layer for blood. I made a layer with flat red color with lower roughness and slight height value. Then I used Substance 3D Painter’s default alphas mixed with my own custom alphas to paint blood and hand-painted the rest. Then I copied the blood layer I created, toned down the red color, and applied levels filter. By adjusting the levels filter, I could describe areas where blood was thicker with darker tones and it gave more realism.

Rendering

After texturing, I imported everything to Marmoset to set up the scene. Marmoset offers preset materials for skin and hair, so I took them and tweaked the values to make materials for the face, the body, and the hair. 

For lighting, Marmoset allows using different HDRIs to create a skydome, so I tried multiple HDRIs downloaded from HDRI Haven (currently Poly Haven) to see the overall tone for the lighting and picked the one I liked. I added extra lights to the scene by left-clicking on the Light Editor. Then I adjusted the light types, intensities, and colors to get the look I wanted to achieve. Then, I tested multiple cameras to get the angle I wanted and used Backdrop to add images to the character’s background. Then I rendered everything to get the final look.

Afterword

It took several months for me to complete this project. It was challenging to take extra hours outside work focusing on creating personal artwork. Character creation is a complex process that takes time and requires learning. But I feel it’s similar to working out at a gym. Putting a foot in the gym might be the hardest part. So, my advice for beginners is: don’t take it too seriously, everybody needs to start somewhere, so make something.

Thanks to 80 Level for sharing my character creation process. I was inspired by other articles on the website, and I hope my article was helpful, too.

Gina Jeon, Character Artist

Interview conducted by Theodore Nikitin