Anatomy of a Node

Before you start using the Node Editor, you need to know how a node works and what its parts are. In Figure 14.3, you can see the dissection of a node into its basic parts. (In this case, it’s an RGB Curves node, which is used to make color corrections to the nodes you put into it).

Noodles: The little colored dots at the left and right sides of a node are called noodles. They support the connections. The noodles on the left are inputs, while those to the right are outputs. Their color tells you what each of those connectors is for: gray noodles are for values (or grayscale images), yellow ones are for RGB images, and blue ones are for vectors. A yellow output noodle should usually be connected to a yellow input noodle in the next node, and there are nodes that convert one type of data into another, i.e., from an RGB image into three grayscale images.

Next to those noodles, there is always a description that tells you what that noodle should receive (if it is an input) or what it’s generating (if it is an output).

Node properties: Each node (and there are a lot, you’ll see) has different properties and is used for different purposes. Inside the node, you’ll find all those properties.

Node connections: A node does nothing by itself. Every single node needs another node to work, and that’s why they are connected. The way and order in which you connect them ultimately defines the final result.

Figure 14.3 These are the main parts of a node.

There are a lot of node types, but there are three main structures: input, output, and modifiers. Input nodes only own output noodles and that’s because they generate or load something, such as an image, a render, or an RGB color. Output nodes are not expected to be modified after they do their job, so they only receive input connections: these output nodes export the final result or display it. Finally, the modifiers are the nodes that are in the middle: they modify inputs and mix them together before they reach the outputs.