Root bricks form the base of your shader. When you start building a new material, the root brick should be the first thing you place in the workspace.
When placed first, the brick name will show as “Surface (1)” or “Volume (1),” etc., to indicate that it was the first brick placed and you'll always know which brick is the base brick for the shader.
As mentioned earlier, root bricks only have input nodes since it is the base of the shader and cannot control the input of any function.
Each root brick has different settings depending on the type of shader. The following sections will cover each type.