This short tutorial covers how to create an old, worn 'illustrative' sketch-style using the Toon shader to create the above image. It covers how to use Base Tonemapping and Edge Detection in combination with bump mapping using a Noise shader to create a hatching effect. Thanks to Javier Garcia-Lajara Herrero for the use of his convent model.
- Start off by assigning a Toon shader to the geometry.
- Change the Filter Type to Contour (Arnold render settings). Without it, you will not be able to see the Toon Edge shading in the render.
- Reduce the Specular Weight to 0 as we do not want any specular shading in the render.
- Create a Skydome light and render the scene. It should look something like this.
- Reduce the Angle Threshold to around 20 (Toon-> Edge Detection). This will give us more detailed edges around the geometry.
- The Edges appear too thick and black. We can fix this by reducing the Edge Width Scaling to around 0.4.
- The Base shading looks too dark for the illustrative effect that we want. We can adjust this by using a ramp to determine how the Base shading is affected by the lighting in the scene. Connect a black and white ramp to the Base Tonemap and increase the amount of white in the ramp until it looks like the image below.
Hatching (Noise Shader)
Next, we will add a hatching style to the Toon Edge. To do this we can bump (or displace) the surface.
- Connect an Arnold Noise shader to Geometry -> Normal (bump mapping) in the Toon shader.
- Increase the number of Octaves to 8. Reduce the Scale in Y to 0.01. This will stretch the noise in the vertical direction and give the impression of a hatching effect.
- Try experimenting with different Noise shaders/settings to get different hatching/stippling effects.
Various Noise shaders -> Bump Mapping
- Connect an HDR map or a Physical Sky to the Skydome light.
- You could also add a pale yellow Base and Emission Color to the Toon shaders to give a worn paper effect.
- Try adding a similar shading effect to the sky using a polygon plane behind the geometry as used in this case.