Houdini 20.0 Networks and parameters

Network editor options

Guide to network editor options.

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Wiring style

Houdini has different ways to drag the wires connecting nodes.

  • You can switch between the available wiring styles using the View ▸ Change network wiring style menu item.

  • You can set the default wiring style on the Themes tab of the Display Options window (see below).

  • The wiring style is saved in the subnetwork, so you can set up different networks with different styles that might be more appropriate for that network’s layout.

Display options


These options are saved per-desktop. Open the Desktop chooser and choose Save current desktop to keep the current settings between sessions.


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Node size to show ring

Choose the maximum zoom level at which the node ring will appear. You can use the slider to set a size manually, or use the Choose node size menu to set a preset size, including “never show the ring” or “always show the ring”.

To set an exact maximum zoom level, zoom the network so the nodes are the largest size you want the ring to appear at, then open the display options, click the Choose node size action menu and choose “Current node size”.

Maximum node name width

Decrease this slider to have the network editor cut off the display of long node names in the network view.

Long wire fading

Houdini fades the middle of long wires so wires across the network don’t obscure everything they cross. This

Decrease this to lessen fading effect in the middle of long wires. Turn this slider all the way down to not fade long wires at all.

Background image brightness

A global scale on background image opacity. Turning this down fades all images into the background more.

Grid spacing

Sets the spacing of the grid. One distance unit in the network editor is roughly the width of a node.



This node has an error and could not cook. Show the info window to read the error message.


This node cooked but generated a warning. Show the info window to read the warning message.


This node has a comment. Show the info window to read or edit the comment. You can also use the checkbox in the info window to show the comment below the badges in the network editor.

Node Locked

You have frozen this node’s output geometry or channels. See the lock flag on SOP nodes, CHOP nodes, and TOP nodes.

Node Unload

This node does not cache its output geometry. See the unload flag

Node has data

This node has cached its output geometry. This badge is hidden by default since it would normally be on most nodes, but if you are trying to debug unload flags you might want to make it visible.

Node needs to cook

This node needs to recompute its output because the inputs or parameters have changed (or, the node has not computed its output for the first time yet). This badge is hidden by default, since Houdini normally cooks nodes automatically as needed. However, if you turn off automatic cooking you might want to make it visible.

Locked HDA

This node is a locked (synced) digital asset.

Unlocked HDA

This node is an unlocked (editable) digital asset.

Time dependent

This node changes based on the current frame. For example, it might have keyframe animation, or it might have an expression that uses the current frame or time.

Cached VEX

The contents of this VOP network have been replaced with cached VEX. If a network can be cached but is not cached, the badge shows a dimmer version.

Not compilable

This node hasn’t been updated to be compilable. This can be useful for checking whether all the nodes in a certain branch of the network can be grouped into a compile block.

Dynamic Work Items

This TOP node is generating dynamic work items. The badge will not appear until the TOP network has been cooked once.

Parameter badges


One or more parameters on this node are constrained/overridden by a CHOP network.


The bone has kinematics (FK or IK) on it.

Has take data

One or more parameters on this node have overrides in the current take.

Text badges

The controls on this tab let you choose how “text badges” appear on nodes. You can hide them, show the full text, or show the text truncated to a few lines.


Each node can have a text comment you can display near the node’s name. You can edit the comment in the node info window.

Detail ID

SOP nodes have an associated unique identifier for their cooked data. The Detail ID is also available from the node info window if you turn the debug flag.

Descriptive parameter

Each node type can specify the most important parameter to understand what the node is doing. For example, for the File node this is the filename. You can display that parameter’s value near the node’s name.

  • When you create a digital asset you can specify the asset’s descriptive parameter on the Node tab of the type properties window.

  • You can use scripting to set a descriptiveparm item in a node’s user data dictionary to a parameter ID to give that node a custom descriptive parameter:

    hou.node("/obj/geo1/blast1").setUserData("descriptiveparm", "group")

    This will override the descriptive parameter set on an asset. However there are some nodes it will not override that generate their own descriptive text.


Wire style for new networks

Sets the default wiring style used for new subnetworks. You can change the wiring style of a subnetwork using View ▸ Change network wiring style.

Default node colors

You can assign default colors per-node-type in the network editor. This menu lets you save the default colors you've set in network editor as a “theme”, and switch between themes. See shape and color themes for more information.

Houdini comes with two color themes already. “Default” colors some of the node types you often want to be able to pick out in a network at a glance. “No colors” doesn’t have any custom colors (this can be useful as a starting point for your own theme).

Default node shapes

You can assign default node shapes per-node-type in the network editor. This menu lets you save the default shapes you've set in network editor as a “theme”, and switch between themes. See shape and color themes for more information.

Houdini comes with three shape themes already. “Default” gives custom shapes to some node types you often want to be able to pick out in a network at a glance. “Flair” is the same as “Default” but uses slightly more charming shapes for Light and Bone. “No shapes” doesn’t have any custom shapes (this can be useful as a starting point for your own theme).


You can turn off display of custom node shapes by turning off View ▸ Show custom node shapes in the network editor.

Networks and parameters


  • Network editor

    How to create, move, copy, and edit nodes.

  • Network navigation

    How to move around the networks and move between networks.

  • Connecting (wiring) nodes

    How to connect nodes to each other to make them work together.

  • Network types and node flags

    Flags represent some state information on the node, such as which node represents the output of the network. Different network types have different flags.

  • Badges

    Badges indicate some status information about a node. They usually appear as a row of icons below the name of the node.

  • Find nodes in a network

    How to use the Find dialog to find nodes based on various criteria.

Editing parameters

Next steps


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