When you think about Blender and 3D design, your mind will probably go towards stylized renders or photorealistic renders and VFX. However, did you know that Blender can also create graphics that can be compared to 2D anime styles and comic book graphics?  

What is Toon Shading?

Toon shading is also referred to as cel-shading. Both terms mean a stylistic shader that imitates the style of a comic book or a 2D drawing. It is also referred to as Non-Photorealistic Render (NPR).

Cel shading is most often used in video games to re-create an animated/hand-drawn look while using 3D objects.

Example of Toon Shading

A toon shader basically separates the color values into two distinct values, sometimes more values depending on the complexity of the shader.  

Here we have an example of a basic stylized 3D render of Suzanne, the monkey head model on Blender.

Fun Fact: Suzanne is a monkey head mesh included in Blender by the developers. 
Stylised 3D Render of Suzanne
Note the gradients in the highlights and shadow of the monkey render. 

And here is the very basic toon shader version:

Toon Shader Render of Suzanne
Note the distinct colour values in the highlight and the shadow parts.

Making a Basic Toon Shader

Let's create a very basic toon shader that will use two color values, one for the base color and one for the shadows.

Creating the Shader

The first step is to create the shader.

First, we take a Diffuse BSDF node, instead of the Principle BSDF. Then add a Shader to RGB which connects to a ColorRamp, which goes directly to the Material Output.

Toon shader nodes

In the ColorRamp, we are dividing the color values exactly in half by changing the Interpolation mode to Constant instead of Linear. And then dragging the right end slider of the gradient to the halfway point, i.e. 0.5.

So the right side of the ColorRamp will be the color that the material will have if the gets light, and the left side will be the color of the shadows. For the monkey, I created five materials for the face, eyes, pupil, nose, and the mouth, each with the same shader but with different color values in the ColorRamp.

Adding Light Sources

Next, it's time to add a light source to see the toon shading in action.  

Adding Sun as a light source

We are adding a sun as a light source because it gives the best results for the shadows. The power should also be bumped up to 1000!

Adding the Outline

The shader is all done, but it looks a little flat without any outline. Here is an easy way to add outlines to your 3D models to imitate a 2D style.

First, we create new material for the outline. It should have Backface Culling enabled.

Outline Material

Then, we add a Solidify modifier to the object that gets this material.

  • Set the Thickness to 0.01 for a thin outline.
  • Then, select the Flipped Normal button.
  • Finally, point the material of the solidify modifier to the outline material by using the Material Offset value. The outline is the sixth material on my object, so the offset value will be 5.
Object Properties

Final Result

Once you add the shader and the material to the object, it should resemble the model shown below.

Adding the Outline

There we have it, the most basic toon shader ready to render 2D looking drawings from your 3D model!

Thanks for reading and catch you in the next one!