In addition to creating materials using the materials panel only, Blender allows you to create a material by routing basic materials through a set of nodes.
A starting material is routed through different nodes that do various things to the material, combined with other inputs. Each node performs some operation on the material, changing how it will appear when applied to the mesh, and passes it on to the next node.
Materials can be split into their RGB components, combined (mixed) with other inputs, and layered on top of one another, much like in the reality a materials aspect is the result of mixing specific paints, thinners, surface prep, and then painting using various techniques under environmental conditions.
The final output can be applied to a mesh, halo, particle, etc.
To use Material nodes, you should already be familiar with general material concepts and how to create materials/textures using the material panel. You should also have a general understanding of the texture coordinate systems available in Blender (e.g. Orco, UV, etc.).
Node system does not make the material pane obsolete. Many features and material settings are still only accessible through the material panel (e.g. Ray Mirror).
"Nodes" are individual blocks that perform a certain operation, and might have one or many different outputs.
Conceptually, there are three basic types of nodes:
- Input Nodes
- these nodes produce information, but do not have any inputs of their own.
- Examples are: Render Layers, Value and RGB nodes.
- Processing Nodes:
- these nodes filter or transform their inputs, to produce one or more outputs.
- Examples are: RGB Curves, Defocus,' and Vector Blur nodes.
- Output Nodes:
- these nodes consume their inputs to produce some kind of meaningful result.
- Examples are: Composite node (which determines the final output used by Blender), Viewer (which displays the output of a socket), and File Output node.
The essential idea of nodes is that you can create an arbitrarily-complex network of nodes, by connecting the outputs of one or more nodes to the inputs of one or more other nodes. Then, you can set appropriate parameters (as you see fit) for each node.
This network is called a "noodle" and it describes how information literally flows through to produce whatever result you want.
You can define node groups, and use those groups as they were a single node.
You can link and append these node groups from other files.
Enabling Node Materials
In the base material panel (Links and Pipeline tab), hit thebutton next to the material name.
By doing this, you're telling Blender to make the material you were on (for example, "MA:Final Material") to become a node tree material, hence the new name "NT:Final Material" (NT: versus MA:).
You can see that it is now asking you to add a new material.
Once you do (New Node Tree Material) you will create a material (MA:) that is under node tree. After adding a material to the node tree, two nodes will appear in the node editor - a material node, and an output node.
By Default, when Material Nodes are used, the material will become solid black, as there is no input material for the material.
Now you have to modify that basic noodle, working in a Node Editor window. The next sections will explain how:
- Node editor window and basic controls
- How to work with a node (general)
- The specific types of nodes available for materials
- Blender Material Nodes - Changelog for the Blender version that introduced material nodes.