without rim shading	with rim shading

A rim shader is useful for achieving a lighting effect related to the contour/outline edges of an object. The above scene demonstrates a simple shader that simulates a fake rim light shading effect. It can be useful for creating fresnel or cartoon-like skin effects.

The shader can be downloaded here.

The rim shader effect is primarily controlled by connecting a utility shader (set to ndoteye) to the specular_weight or base_color parameter of a standard_surface shader.

_{Final shader network}

Utility Shader

• Start off by connecting a utility shader to the specular_weight of a standard_surface shader. The shade_mode is set to ndoteye which provides the basic rim shading effect. However, the effect needs to be reversed.

Complement shader

• A complement shader is inserted before the utility shader to invert the ndoteye effect of the utility shader.

  rim shader color set to white	No rim shader (standard_surface)

Color Correct shader

A color_correct shader can also be added to refine the rim shading effect. The images below show the effect adjusting the gamma parameter has on the rim shading effect.

Specular Color

Adjusting the specular_color can also give different effects.

specular_color: yellow	specular_color: black

_{Thanks to sample and hold for the use of the toy scan model.}