Houdini 12 Network and parameters

Overview

Connections between nodes have different meanings in different network types.

  • In Object (OBJ) networks, the connections control parenting (connect child objects to the outputs of parent objects).

  • In particle (POPs), geometry (SOPs), and compositing (COPs) networks, connections control the flow of geometry data through the network.

  • In render output (ROPs) networks, connections control dependencies between render passes (connect later renders to the outputs of prerequisite renders).

How to

Tip

You can hold Space and pan and zoom the network view while connecting, if you need to bring the node you're connecting to into view.

To...Do this
Connect existing nodes

  1. Click the input/output connector of a node.

  2. Click another node, or click in empty space to cancel the connection.

Tip

You can also press Alt + LMB on a node to start the connection. This is useful in large networks where you may be zoomed out, making the nodes appear smaller.

or

  • Drag and drop a node (or multiple selected nodes) over an existing connection.

    This connects the first input. To connect to the next available input instead, hold ⇧ Shift as you drag and drop.

    Note

    If the node you are dragging has no input connector, the wire will reconnect to its output, disconnecting the upstream node.

Manage connections

  • Right-click a wire to see a menu of operations you can perform on the wire.

Delete a connection

  • Click the connection’s input, then click in empty space in the layout area.

    or

  • Right-click the wire and choose Disconnect.

Branch an already-connected output to another input

  1. Click an output that is already connected to something.

  2. Click the additional input.

Create a new node and connect it to an input

  1. Press RMB on the input box of a node.

  2. A menu pops up showing the nodes that can be connected here. Choose an node.

  3. Click to create a node and connect it automatically.

Create a new node and insert it in the output stream

  1. Press RMB on the output box of a node.

  2. A menu pops up showing the nodes that can be connected here. Choose an node.

  3. Click to create a node and connect it automatically.

Create a new node and branch it off the output stream

  1. Press MMB on the output box of a node.

  2. A menu pops up showing the nodes that can be connected here. Choose an node to create a node and branch it automatically.

Connect multiple node outputs at once to a single input

This is useful when you want to connect a bunch of nodes to a Merge node.

  1. Select the nodes whose outputs you want to wire.

  2. Click the output of one of the selected nodes and then click the input of the destination node.

    Houdini wires the outputs of all the selected nodes to the input of the destination node.

Remove a node from a network of nodes

Hold LMB on a node (or multiple selected nodes) and shake from side to side.

Note

This only works for multiple selected nodes if they form a linear chain, or a mix of linear node chains and single selected nodes.

Get help on an input

  • Press MMB on the input box of a node. Houdini shows a short description of what kind of input is expected.

Reordering inputs

Many nodes let you connect multiple nodes to their input, and the order of the inputs is sometimes significant (for example, Render nodes (ROPs) render their inputs in order).

To reorder the inputs, use the controls on the input list in the parameter editor.

  1. Select the node in the network pane.

  2. In the parameter editor, scroll down to the bottom of the panel. For nodes with multiple inputs there will be a list of inputs.

  3. Drag and drop the inputs in the list or click the up-arrow icons to reorder them.