Houdini 20.0 Reference Windows

Persistent manipulator editor window

This window lets you change the bindings between the handles of persistent manipulators and the parameters they modify.

The top-left sub-pane lists persistent manipulators. Use the menu at the top of the list to create a new manipulator.

The pane below the manipulator list shows a tree of all parameters in the scene.

When you select a manipulator in the list on the left, the list on the right shows you which parameters the handles of the manipulator are bound to.

To...Do this

“Bind” a handle to a parameter (so when the user moves the handle the parameter changes)

  1. Select the manipulator from the manipulator list.

  2. If you are using the persistent handle editor window, drag the parameter from the bottom-left list onto the handle in the right list. If you are using the handle tab of the operator type window, use the menu button to choose the parameter from the list of promoted parameters.

Bind a handle parameter to a constant value

*Set the handle’s binding to !constantexpression

Specify a conversion function between the handle parameter and the operator parameter

Set the handle’s binding to { a, b, c, d, chname }. This fills in the function f(x) = (ax + b) / (cx + d).

For example, to have the handle be the negative value of the channel, use { -1, 0, 0, 1, chname } To have the handle be the reciprocal value of the channel, use { 0, 1, 1, 0, chname }.

Each handle can only bind to a single parameter.


Shows the basic type of the manipulator (selected when you chose the type of manipulator to create). For example, xform for a transformation manipulator. This value is not editable.


Human-readable name for the manipulator. This must be unique within the asset.


Manipulator-specific list of default values. These handles differ on a per handle basis. The best way to find out the values is to create an HDA, and with the Type Properties window open, click RMB the handle and choose Export Handle To Digital Asset.


Changes to handle bindings take effect when you click Apply or Accept. Any changes you make to the handles outside this pane will cause any uncommitted changes to be lost.