Image from Coco

Defining the How and What of Space and Color

If you just add some lights and some objects to a scene in RenderMan, it makes a picture, but the shapes are a solid color, and it only has the details that it was modeled with. Shading is a way to refine and enhance both the color and detail, turning clay-like models into imagery to match or exceed reality.

Shading in RenderMan is divided into two domains: Space and Color.

When RenderMan shades a 3D object, you are given the opportunity to refine the location of the final modeled surface in space in displacement shading.
You are then given the tools to refine how an object interacts with light to define its color in material shading.

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Displacement and material shading is described to the renderer via networks of interconnected nodes like textures connected to material properties.

A value that varies over the surface of your object is called a shading signal, and these signals flow through the network connections to be created, altered, or mixed inside of the network nodes. In RenderMan, we further divide these networks into nodes that define the How and the What of your surface.

Most of the network is full of Pattern nodes that describe the What – they help the shading artist control exactly what the signal values are at every point on the surface.

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