How to Create Custom Nodes and Node Groups in Blender 3D using bpy

To create custom nodes and node groups using the Blender Python API (bpy), you can follow these detailed steps. This guide will cover the creation of custom nodes and node groups, how they are defined, and how to integrate them seamlessly into Blender's node editor.

Introduction

Custom nodes and node groups can be a powerful way to extend Blender's functionality and simplify complex node networks. This article will provide a comprehensive guide on how to create custom nodes and node groups using bpy in Blender 3D.

Creating Custom Nodes

Creating a custom node involves defining a new class that inherits from This class defines the properties and methods of the custom node. Here is an example:

import bpy
# Define a new custom node
class MyCustomNode():
    bl_idname  CUSTOM_NODE
    bl_label  My Custom Node
    bl_icon  OBJECT_DATA
    # Define properties
    my_input: (
    name  My Input, 
    default  0.0
    )
    my_output: (
    name  My Output, 
    default  0.0
    )
    def init(self, context):
    # Initialize node
    (NodeSocketFloat, My Input)
    (NodeSocketFloat, My Output)
    def update(self):
    # Update node when input changes
    _output  _input * 2.0

To register the custom node, use the register() function:

def register:
    _classMyCustomNode

To unregister the node, use the unregister() function:

def unregister:
    bpy.utils.unregister_class(MyCustomNode)

Creating Custom Node Groups

A node group is a collection of nodes that can be treated as a single node. Creating a custom node group involves defining a new class that inherits from Here is an example:

import bpy
# Define a new custom node group
class MyCustomNodeGroup():
    bl_idname  CUSTOM_NODE_GROUP
    bl_label  My Custom Node Group
    def init(self, context):
    # Initialize node group
    (typeNodeGroupInput)
    (typeNodeGroupOutput)
    def update(self):
    pass
# Register the node group
def register:
    _classMyCustomNodeGroup
# Unregister the node group
def unregister:
    bpy.utils.unregister_class(MyCustomNodeGroup)

Note that the update() method should be implemented to handle any changes within the node group.

After defining the custom node and node group, you can register them using the register() and unregister() functions, respectively. These can be added to the system to ensure they are loaded and unloaded when Blender starts and closes.

Conclusion

Creating custom nodes and node groups is a powerful way to extend Blender's functionality and optimize workflows. By following the steps outlined in this article, you can create your own custom nodes and node groups and integrate them into Blender for more efficient and expressive node network design.