Mix and Add Shaders

Of course, the shaders mentioned before can’t do much on their own. That’s why inside the Shaders list there are two special shaders that are actually not shaders: Mix Shader and Add Shader.

Mix Shader lets you combine two of the other shaders and adjust the influence each one of them has on the result. Imagine that you want a simple colored surface that has some shininess: you can use a Mix Shader and, in its two slots that appear, you can add a Diffuse BSDF and a Glossy BSDF. Adjust their properties and colors, and finally define the Mix Shader Fac (Factor). A value of 0 will show only the first shader, while 1 will show only the second one, as if they were layers; values in between will blend the effects of the two shaders.

Add Shader, instead of letting you select the blending values for the two shaders, will just add the two colors together and will generally give you brighter results.

Of course, you can add Mix Shaders inside Mix Shaders to get even more complex shaders. For example, imagine a rusty metal; you can have a mixture of shaders for the parts of the surface that don’t have rust and combine that mixture with another mix of different textures and materials for the rusty parts. Can you see how you can make Cycles materials as complex as you want?