Discovering shaders

Shaders were defined as two things at the beginning of this chapter: a piece of code and a user manual. Have you felt like you’ve been writing code so far? Most likely, no.

Nevertheless, behind that Material user interface, there is a code layer, which is the shader. For example, the default shader you’ve been using so far has hundreds of lines of code. The following is only a portion of the code that makes that shader:

metallic = saturate(metallic);
transmission = saturate(transmission);
float diffuse_weight = (1.0 - transmission) * (1.0 - 
  metallic);
transmission *= (1.0 - metallic);
float specular_weight = (1.0 - transmission);
clearcoat = max(clearcoat, 0.0);
transmission_roughness = 1.0 - (1.0 - roughness) * (1.0 -
  transmission_roughness);
specular = max(0.0, specular);

Luckily for you, you don’t have to write a single line of code. More importantly, Blender interprets the shader code so that it can offer...