Houdini 12 Network and parameters

Ignoring nodes

Several node types, including surface nodes, particle nodes, dynamics nodes, compositing nodes, and channel nodes, have a bypass flag that turns the effect of the node off, effectively passing its input directly through to its output. This lets you temporarily turn off expensive operations, flip back and forth to see the effect of a node, and try out variations.

In surface networks, the bypass flag is the yellow flag at the left end of the node. When a node is bypassed, it has a striped background to make it more visually apparent.

See node flags for more information.

Node colors

You can color the nodes in the network editor. This lets you annotate different areas, functions, and/or classes of nodes in the view using color. For example, in a shading network you could color all the lighting model VOPs yellow to make them easier to find at a glance.

  1. Press C to show the color palette.

  2. Select the node(s) you want to color.

  3. Click a color in the palette.

  4. Press C again to hide the palette.

Sticky notes

Sticky notes can be created in the network editor. This will create a yellow text box where you can comment on nodes or networks.

To...Do this
Create a sticky note

Press Ctrl + P in the network editor.

Add text

Click the text box and type.

Move a sticky note

Drag the bar across the top.

Resize a sticky note

Drag from one of the corners.

Minimize a sticky note

Click the minimize button at the top right of the note.

Remove a sticky note

Click the X button at the top right of the note.

Network boxes

Network boxes let you group nodes together visually. This is useful when you can’t or don’t want to collapse the nodes into a subnetwork but you want to distinguish them from other nodes. For example you could group the nodes representing different limbs of a character rig in different boxes.

To...Do this
Create a network box
  1. Select the nodes you want inside the new box.

  2. Press RMB on the network background and choose Add > Create Network Box from Selected.

Note

You can embed network boxes inside other network boxes.

Add or remove a node to/from a network box
  • Drag the node onto or out of the box.

Move or resize a network box
  • To move a network box, drag the bar across the top. To resize it, drag from one of the corners.

Remove a network box
  • Click the X button at the top right of the box.

Collapse a box to a stamp
  • Click the left button at the top right of the box.

Assign colors to network boxes
  1. Press C in the network editor to show the palette.

  2. Select the network box you want to color.

  3. Click a color in the color palette.

Subnetworks

Subnetworks let you encapsulate multiple nodes inside a single node, streamlining your network visually and conceptually. Note that putting nodes inside a subnetwork changes their path.

The subnetwork node can have up to four inputs, which are passed down to special nodes inside the subnetwork.

To...Do this
Create an empty subnet
  • Use the tab menu to create a Subnetwork node.

Create a subnetwork from existing nodes
  1. Select the nodes you want to go inside the new subnet.

  2. Right click one of the nodes and choose Collapse Selected into Subnet.

Move one or more nodes inside a subnetwork
  1. Select the node(s) and choose Edit > Cut.

  2. Go inside the subnetwork and choose Edit > Paste.

Connect the subnet’s inputs to node inputs inside the subnet
  1. Go inside the subnet.

  2. The layout view shows four pseudo-nodes which represent the subnet’s inputs. Connect the output of one of the pseudo-nodes to the input of one of the real nodes in the subnet.

Choose the subnet’s output
  • Set the display flag of the node you want to provide the subnet’s output.

Label the subnet’s inputs
  1. View the subnet’s parameters in the parameter editor and click the Subnet tab.

  2. Edit the Subnet Input # text fields to control the message that pops up when the user presses MMB on the inputs.

Node comments

To...Do this
Edit a node’s comment field
  1. Select the node in the network editor.

  2. In the parameter editor, click the Gear menu and choose Edit comments.

  3. Type a comment into the text field and click Accept.

Display a node’s comment

In the network editor, hold MMB on the node.