This is documentation of my process, insights, and findings in exploring an anime look in Blender. Though not a tutorial in itself, I link to every resource and guide I found useful.


Overview

The final product, using a borrowed 3D model and background image.

Contents + Links
  1. Goals & References
  2. Colouring & Prep
  3. Linework
  4. Normal Editing
  5. Animation & Post-Processing

1. Goals and References

My goal was to understand producing cel-shaded-like shading using normals and explore line art. Knowing this, I cut corners in other areas to reduce overhead and avoid being distracted by other elements.

To avoid colour theory and tone, I used a screencap from Cowboy Bebop to reference the exact colours used, and to use the background.

To avoid character sculpting, I used a model from Overwatch, a model with an intended visual that's completely different than what I'm aiming for.

Being a test of achieving a specific look, references are mandatory. My chosen reflected the specificity of what I wanted to achieve: a heavy hand in face shading with a clear form or clear shadow shapes, determined by artistic decision and not necessarily by realism. Examples were from 80s anime (heavily shaded), and high-production anime (more delicate, deliberate, and detailed in face lighting).


2. Colouring & Prep

Tutorial used: Material Based Anime Shading by Royal Skies

Toon shader applied to all materials, with colours picked from my reference screenshot

Simple half-sphere for the pupils. Having a pupil as a separate mesh allowed for fine control which turned out useful later on


3. Linework

Tutorial used: Grease Pencil Line Art Tutorial by SouthernShotty

The commonly used Inverted Hull method was too uncontrollable and relied on deforming meshes in specific ways for enough depth for contour lines to appear. Not only that, but overlapping objects created unexpected line inconsistencies. I haven't figured out how to make this work and it didn't seem worth it when I found out about the grease pencil method.

My initial test with the Inverted Hull method. Notice the broken lines on hat strap and jawline.

With the grease pencil method, my contours had a consistent line-weight and expected results. I can imagine turning these into strokes and scaling vertices to create line-weight variation.

Grease pencil line art which picks up on contours as well as material changes and intersections

The real benefit was being able to add detail lines onto the mesh using 'Edge Marks'. These Edge Marks are set by 'marking edges' on the mesh, similar to 'mark sharp'. These lines sit on top of the mesh and thus, are properly obstructed by mesh volumes. These lines can be achieved by texturing the model with an image with detailed lines, but I find that process inconvenient.

Line Art with Edge Marks

Edge Marks I had added in

Distinct to selling the mature anime look are these selective artist-informed details — eye lids, bottom lip, ear details. I also used Edge Marks to bring definition to the beads, hat, and pipe, which were not at steep enough angles to be generated by contours.


4. Normal Editing

Tool used: BNPR Abnormal Plugin, Setup and detail video by Royal Skies
Theory: BK Kame's video explains why and how you edit normals
Process/Theory: Normal Editing 101

A quick rundown of what editing normals does in this context, is customizing the direction a face will catch and bounce light. By controlling this, we can make groups of faces catch light at the same time to create controlled shadow shapes.

Video demonstrating on how the normals affect lighting, before and after editing.

My first attempt was a mess, and that's because I was trying to figure out the shadows as I went along the mesh.

To start fresh, I used a proxy mesh via this and this tutorial by Royal Skies. This method uses normals from the proxy to determine the normals of the final mesh. Unlike the tutorials which had a softer look, I preferred a blocky proxy mesh to create clear divisions on the face. Although I don't think the proxy mesh helped that much technically, I now understood what I was doing. I needed to adjust normals in larger groups, and there needs to be a consistency in where they faced.

Left: My proxy mesh, Right: Proxy mesh data transferred

My biggest takeaway is: The way light will shade the face needs to be planned at the very beginning, and the mesh topology needs accommodate those shapes. My method for planning at this point was using Mark Sharp (in blue) to mark the shadows on the mesh. I saw this very helpful video by Activemotionpictures after I finished, which talks about planning ahead.

I didn't want to mess with the meshes too much but I DID want to hack together a cheek triangle (yellow) and a nose highlight (red) which I felt were important for the look. I rearranged the mesh a bit to get me close enough to the effect.

There are a few areas I wanted permanently dark. This included the inside of the ear, the inner corners of the eyelid, the underside of the nose, and the bottom of the lip.

At this point, I felt to achieve my desired look would require a lot of mesh adjustments which I didn't want to mess around with. I felt I learned what I set out to learn, even though the normals on all the props and faces aren't perfect.


5. Animation & Post-Processing

My post-processing set out to imitate slightly degraded anime dvd rips, by studying the Cowboy Bebop reference I initially used.

Line art is made rougher using a 'simple choker', with a small red-tinted blur to give the linework some haziness

Colour is slightly blurred so the edges of shadow aren't as harsh, and there is 'match grain' to create grain according to the reference

The animation was extremely simple, and animated on 3s at 24fps. The rule of thumb was 2-3 poses per keypose. To add a little more length, I slapped on a voice clip or two and animated a simple mouth movement.