Houdini 17.0 Reference Windows

Edit Parameter Interface window

Creates, imports, or edits parameters on a node.

On this page

Overview

The controls in this window let you edit which parameters appear in the parameter editor for a node.

You can:

  • Import or promote parameters from another node, such as from a surface node up to its geometry container, to make controls more easily available.

  • Add rendering properties.

  • Add extra ("spare") parameters to a node that can be used by expressions and/or scripts.

Note

This window lets you add/edit/remove parameters for a particular node. It does not affect all nodes of the same type. To edit the parameter interface of a digital asset, use the operator type properties window.

Open the window

  1. Select the node you want to edit in the network editor.

  2. In the parameter editor, click the Gear icon and choose Edit parameter interface.

    This window lets you create new parameters on a node, add rendering controls, and copy parameters from other nodes onto this one.

Import parameters from another node

  1. Open the Edit Parameter Interface window (see above).

  2. Click the From Existing Nodes tab on the left side. Use the tree control to select a parameter on a node, then drag it into the Existing parameters pane, or click the "move right" button.

    OR

    Select the other node in the network editor and drag the parameter directly from the parameter editor into the Existing parameters pane of the Edit Parameter Interface window.

  3. Use the options under Parameter Description on the right side of the window to customize the destination parameter’s appearance and behavior (this does not affect the source parameter on the other node).

When you import a parameter from another node, Houdini automatically edits the source parameter to be a parameter reference expression that looks up the value of the destination parameter. Once you import a parameter, you should only edit the destination parameter, not the source parameter (unless you delete the destination parameter to break the connection).

Render properties

See the section on render properties for information on rendering properties.

  1. Open the Edit Parameter Interface window (see above).

  2. Click the Render Properties tab on the left side. Use the tree control to select a property, then drag it into the Existing parameters pane, or click the "move right" button.

Spare parameters

Spare parameters let you store extra information on a node. You can add spare parameters to any node to provide extra storage for values and expressions. They are not used directly by the node, but you can reference them in other standard node parameters using expressions. Adding a spare parameter to a node only adds it to that node, not all the nodes of that operator type.

You can keyframe spare parameters, reference them, and add them to takes .

  1. Open the Edit Parameter Interface window (see above).

  2. Click the By type tab on the left side. Select the type of parameter you want to add, then drag it into the Existing parameters pane, or click the "move right" button.

  3. Use the options under Parameter Description on the right side of the window to customize the parameter’s appearance and behavior.

Parameter Description

Example

Create a sphere and add squash and stretch

  1. In this example, we’ll create a new "squash" parameter on a ball object by promoting a parameter from a node inside the ball’s geometry network.

  2. First, use the Sphere tool on the Create shelf to create a sphere. In the operation control toolbar (along the top of the viewer), set the sphere’s Primitive type to Polygon and the Frequency to 4.

  3. Select the sphere and use the Squash and Stretch tool on the Deform shelf to add squash and stretch to the sphere.

  4. The squash and stretch tool automatically dives into the sphere’s geometry container to show you its surface nodes: a sphere node that creates the sphere geometry, and a twist node set to squash and stretch.

  5. Select the twist node (probably called squashstretch1). In the parameter editor you can see that its Operation parameter is set to Squash & Stretch.

  6. Set the node’s Primary axis parameter to Y axis. Set the Pivot to 0 -1 0 to move the center of the squash and stretch to the bottom of the sphere (since the sphere is 1 unit in radius, moving the pivot down 1 along the Y axis puts it at the bottom of the sphere).

  7. Move the mouse over the Strength text box and press and hold . Drag left and right to squash and stretch the sphere.

    Note that negative values squash the sphere down, positive values stretch it up, and that the values need to be fairly small, so the slider beside Strength which goes from 0 to 360 is not very useful. You’ll want to type in values or use the ladder instead.

Promote the Strength parameter from the squash and stretch node

Now we’ll promote the Strength parameter from the squash and stretch node up to the geometry container so we can edit it at the Scene level.

  1. Click Back to return the Scene level.

  2. Click the ball’s object container to show its parameters in the parameter editor.

  3. In the parameter editor, click the Gear menu and choose Edit parameter interface.

  4. In the Edit Parameter Interface window, click From existing nodes on the left side.

  5. Use the tree control to find the squash and stretch node inside the ball. Open it up to show its parameters inside. Drag the strength parameter onto the Existing parameters tree, just above the Translate parameter.

  6. In the Parameter description section on the right side, set the Label option to Squash. This is the human-readable label that will appear in the parameter editor.

  7. In the Interface options subsection below, set the Range to -2, 2.

  8. Click Apply.

  9. Try using the new Squash parameter on the object.

Windows