It is better to use the Toon shader for this type of shading effect.
This tutorial shows you how to create a 'stylized' cartoon shading effect using Arnold. We will use the facing_ratio in combination with a variety of other utility and color shaders to fine tune the effect. The original Maya scene files for this series of tutorials can be downloaded from Autodesk's Hyperspace Madness production. In this case, a standard_surface shader was used. Alternatively, you could also use a utility shader and set the shade_mode to flat. Out Value of Ramp connected to uCoord of Ramp A utility shader (shade_mode set to nodoteye) connected to a ramp can also be used to create a similar facing ratio effect. You could also try experimenting with some of its color modes to produces different toon shading effects. Note that the ndoteye shading does not appear in specular reflections. Blue color added to multiply of color_correct shader Multiple shaders connected to the same Ramp and facing_ratio shader The facing_ratio shader can be used to add more control over the appearance of the cartoon shading effect. Below are the results when adjusting the bias and gain attributes. The range shader can also be used to fine-tune the cartoon shading effect by remapping the input values of the ramp.
range shader connected to emission_color. Roll over image to see without it. That concludes this tutorial on cartoon shading. Why not try these shading techniques using some of the freely available models from Autodesk's Hyperspace Madness production. You can use this node to change shading based on any lights in the environment. In the example below, the Surface Luminance shader is used to drive the V Coords of a ramp that is connected to the base_color of a standard_surface shader. SurfaceLuminance shader connected to V Coord of RampThe shader used in this tutorial can be downloaded here.
Workflow
Standard Surface
Facing Ratio
Utility Shader
Color Correct
Bias
Gain
Surface Luminance