From BlenderWiki

The Node Editor is used to edit the various tools within Blender that make use of a directed-acyclic execution graph (don't worry, you never have to read that again). Basically, "nodes" are little windows that you connect together to form networks. Nodes have inputs and outputs, some of which are optional, some of which are required.

[edit] Loading the Node Editor

Make sure you have a free area window in Blender to use. The Node Editor can be found in the areatype menu, as shown in the image.

To use nodes, you must press "Use Nodes" in the header of the Node Editor window. In the case of material nodes you must press either this button or its equavalent in the material buttons for every object you use material nodes with. See the section on compositing nodes for how to access that.

[edit] The Node Editor Window

[edit] The Node

The Node Editor window is used to either edit an object's material nodes, or to edit the scene's compositor node tree. You can switch between the two modes by clicking either the left (material) or right (compositor) buttons on the header.

The following image illustrates what a node is:

1. The node's titlebar. This contains the node's name, along with several different collapse buttons.
2. The left side of a node has input sockets. Blue sockets accept vectors, yellow sockets accept colors, and grey sockets accept single values.
3. The right side of a node has output points. Blue points produce vectors, yellow points produce colors, and grey points produce single values (like alpha).
4. The arrow on the left completely collapses or "shades" the node. Click the smaller node again to see its contents.
5. The plus-sign button on the right side of the titlebar hides unused input/output sockets. Click again to see all sockets, connected or not.
6. The double-line button in the middle right hides or shows all of the interface controls, simplifying the node's appearance. Click again to see the controls.
7. The sphere button on the far right of the titlebar hides or shows the preview image.
8. A curved line shows a connection from an output socket to an input socket. The socket types must match. Connections associated with the active node are highlighted for better visibility.

To connect an input point to an output point, simply drag from one socket to the other. Attempting to connect sockets of different types (e.g., different colors) will result in a converter node being added automatically to change the output point type to the input point type. You can also make many connections feeding from the same output socket, but only one connection can enter an input socket.

[edit] Navigation in the Node Editor

Navigation in the Node Editor window is the same as in all other Blender windows. Middle mouse button hold (emulated with Alt LMB hold) pans the space, while also holding Ctrl LMB will zoom in/out (note you have to stop panning to do this).

[edit] Adding a Node

To add a node, simply press Shift A or Space in the node editor and select a node from the list.

[edit] Editing Modes In The Node Editor

• Compositing
• Materials