Python example scripts

Tools Shelf

Create a Null and Merge

Used to untangled networks

python

import hou


OFFSET = -1.0


# Process a single node
def create_null_merge(node : hou.Node, base_name : str):
    node : hou.Node
    node_name: str = node.name()
    node_path : str = node.path()
    node_position = node.position()
    root: str = node_path[:node_path.rfind("/")]
    null_node : hou.Node = hou.node(root).createNode("null")

    null_pos : hou.Vector2 = hou.Vector2(node_position[0], node_position[1] + OFFSET)
    null_node.setPosition(null_pos)

    null_node.setInput(0, node)
    null_node.setName(base_name, unique_name=True)

    merge_node :hou.Node = hou.node(root).createNode("object_merge")
    new_offset = OFFSET*2
    merge_node_pos : hou.Vector2 = hou.Vector2(node_position[0], node_position[1] + new_offset)
    merge_node.setPosition(merge_node_pos)
    merge_node_name : str = f'merge_{base_name}'

    merge_node.setName(merge_node_name, unique_name=True)
    rel_path : str = merge_node.relativePathTo(null_node)
    merge_node.parm("objpath1").set(rel_path)


# Main
nodes = hou.selectedNodes()


if (len(nodes) == 0):
    hou.ui.displayMessage("Please select a node")
    exit()

input : tuple = hou.ui.readInput("Enter Null node", initial_contents="Node name")
base_name: str
base_idx : int

base_idx, base_name = input

if base_name == "":
    hou.ui.displayMessage("Empty name!")
    exit()

print(f'Using {base_name} for null node')

for node in nodes:
    create_null_merge(node, base_name)

print("Done")

Reference: Step-by-Step Guide: How to Place Nodes in Houdini with Python