What is Node and NodeTree in Blender?
To explain the words “Node” and “NodeTree” in Blender. This article doesn’t contain detail of each nodes and their usage.
What is Node?
Node is a data processing mechanism that has zero or more input sockets and output sockets and processing function.
Nodes can be connected to each other.
Blender Nodes has Title, Sockets, Properties. Click Blender document for detail.
What is Node Tree
Node Tree is the whole structure consists of connected nodes.
Node type in Blender
There are three types of node trees and node editor in Blender, Shade Nodes, Composite Nodes and Texture Nodes. Please refer to Blender 2.80 Manual “Introduction” for detail.
Materials, lights and backgrounds are all defined using a network of shading nodes. These nodes output values, vectors, colors and shaders.Blender Document: Shader Nodes (https://docs.blender.org/manual/en/dev/render/shader_nodes/introduction.html )
Compositing Nodes allow you to assemble and enhance an image (or movie). Using composition nodes, you can glue two pieces of footage together and colorize the whole sequence all at once.You can enhance the colors of a single image or an entire movie clip in a static manner or in a dynamic way that changes over time (as the clip progresses).Blender Document: Compositing Nodes
( https://docs.blender.org/manual/en/dev/compositing/introduction.html )
Blender includes a node-based texture generation system, which enables textures creation by combining colors, patterns and other textures in the same way as shader writing with material nodes.Blender Document: Texture Nodes
( https://docs.blender.org/manual/en/dev/editors/texture_node/introduction.html )
How to manipulate Nodes?
You can manipulate Nodes and create node network with different types of node editors. The basic operation method of node editor is here.
NodeTree in PythonAPI
The word “NodeTree” is also used in Blender PythonAPI( https://docs.blender.org/api/current/bpy.types.NodeTree.html ). bpy.types.NodeTree(ID) class, which has nodes attribute and links attribute, can get NodeTree specified by the ID. Nodes is bpy_prop_collection of nodesthat make up the node tree. Links is bpy_prop_collection of links to connect the nodes.