I’m testing the custom node editor template in 2.76a
import bpy
from bpy.types import NodeTree, Node, NodeSocket
# Implementation of custom nodes from Python
# Derived from the NodeTree base type, similar to Menu, Operator, Panel, etc.
class MyCustomTree(NodeTree):
# Description string
'''A custom node tree type that will show up in the node editor header'''
# Optional identifier string. If not explicitly defined, the python class name is used.
bl_idname = 'CustomTreeType'
# Label for nice name display
bl_label = 'Custom Node Tree'
# Icon identifier
bl_icon = 'NODETREE'
# Custom socket type
class MyCustomSocket(NodeSocket):
# Description string
'''Custom node socket type'''
# Optional identifier string. If not explicitly defined, the python class name is used.
bl_idname = 'CustomSocketType'
# Label for nice name display
bl_label = 'Custom Node Socket'
# Enum items list
my_items = [
("DOWN", "Down", "Where your feet are"),
("UP", "Up", "Where your head should be"),
("LEFT", "Left", "Not right"),
("RIGHT", "Right", "Not left")
]
myEnumProperty = bpy.props.EnumProperty(name="Direction", description="Just an example", items=my_items, default='UP')
# Optional function for drawing the socket input value
def draw(self, context, layout, node, text):
if self.is_output or self.is_linked:
layout.label(text)
else:
layout.prop(self, "myEnumProperty", text=text)
# Socket color
def draw_color(self, context, node):
return (1.0, 0.4, 0.216, 0.5)
# Mix-in class for all custom nodes in this tree type.
# Defines a poll function to enable instantiation.
class MyCustomTreeNode:
@classmethod
def poll(cls, ntree):
return ntree.bl_idname == 'CustomTreeType'
# Derived from the Node base type.
class MyCustomNode(Node, MyCustomTreeNode):
# === Basics ===
# Description string
'''A custom node'''
# Optional identifier string. If not explicitly defined, the python class name is used.
bl_idname = 'CustomNodeType'
# Label for nice name display
bl_label = 'Custom Node'
# Icon identifier
bl_icon = 'SOUND'
# === Custom Properties ===
# These work just like custom properties in ID data blocks
# Extensive information can be found under
# http://wiki.blender.org/index.php/Doc:2.6/Manual/Extensions/Python/Properties
myStringProperty = bpy.props.StringProperty()
myFloatProperty = bpy.props.FloatProperty(default=3.1415926)
# === Optional Functions ===
# Initialization function, called when a new node is created.
# This is the most common place to create the sockets for a node, as shown below.
# NOTE: this is not the same as the standard __init__ function in Python, which is
# a purely internal Python method and unknown to the node system!
def init(self, context):
self.inputs.new('CustomSocketType', "Hello")
self.inputs.new('NodeSocketFloat', "World")
self.inputs.new('NodeSocketVector', "!")
self.outputs.new('NodeSocketColor', "How")
self.outputs.new('NodeSocketColor', "are")
self.outputs.new('NodeSocketFloat', "you")
# Copy function to initialize a copied node from an existing one.
def copy(self, node):
print("Copying from node ", node)
# Free function to clean up on removal.
def free(self):
print("Removing node ", self, ", Goodbye!")
# Additional buttons displayed on the node.
def draw_buttons(self, context, layout):
layout.label("Node settings")
layout.prop(self, "myFloatProperty")
layout.template_preview(bpy.data.textures[0], show_buttons=False)
# Detail buttons in the sidebar.
# If this function is not defined, the draw_buttons function is used instead
def draw_buttons_ext(self, context, layout):
layout.prop(self, "myFloatProperty")
# myStringProperty button will only be visible in the sidebar
layout.prop(self, "myStringProperty")
# Optional: custom label
# Explicit user label overrides this, but here we can define a label dynamically
def draw_label(self):
return "I am a custom node"
### Node Categories ###
# Node categories are a python system for automatically
# extending the Add menu, toolbar panels and search operator.
# For more examples see release/scripts/startup/nodeitems_builtins.py
import nodeitems_utils
from nodeitems_utils import NodeCategory, NodeItem
# our own base class with an appropriate poll function,
# so the categories only show up in our own tree type
class MyNodeCategory(NodeCategory):
@classmethod
def poll(cls, context):
return context.space_data.tree_type == 'CustomTreeType'
# all categories in a list
node_categories = [
# identifier, label, items list
MyNodeCategory("SOMENODES", "Some Nodes", items=[
# our basic node
NodeItem("CustomNodeType"),
]),
MyNodeCategory("OTHERNODES", "Other Nodes", items=[
# the node item can have additional settings,
# which are applied to new nodes
# NB: settings values are stored as string expressions,
# for this reason they should be converted to strings using repr()
NodeItem("CustomNodeType", label="Node A", settings={
"myStringProperty": repr("Lorem ipsum dolor sit amet"),
"myFloatProperty": repr(1.0),
}),
NodeItem("CustomNodeType", label="Node B", settings={
"myStringProperty": repr("consectetur adipisicing elit"),
"myFloatProperty": repr(2.0),
}),
]),
]
def register():
bpy.utils.register_class(MyCustomTree)
bpy.utils.register_class(MyCustomSocket)
bpy.utils.register_class(MyCustomNode)
nodeitems_utils.register_node_categories("CUSTOM_NODES", node_categories)
def unregister():
nodeitems_utils.unregister_node_categories("CUSTOM_NODES")
bpy.utils.unregister_class(MyCustomTree)
bpy.utils.unregister_class(MyCustomSocket)
bpy.utils.unregister_class(MyCustomNode)
if __name__ == "__main__":
register()
I have only added this line
layout.template_preview(bpy.data.textures[0], show_buttons=False)
I have created a texture for testing.
The problem is that preview sometimes is empty until the node get the focus.
Is this a bug?
I have seen that the texture panel (on the object properties) is not working when the nodes are active.
If I change the size of one preview in one node (make higher or lower), the preview size of the other nodes change too.