Scoping a parameter displays the parameters in the animation editor and the channel list (the channel list is a miniature version of the animation editor that lets you view and manipulate scoped parameters but does not graph their values).

When press K to set keyframes, Houdini keys the values of the scoped parameters. Therefore it’s often important to know which parameters are scoped, although as long as you have an object selected Houdini will usually auto-scope

To see what channels are scoped, add a pane tab or open a floating window containing the animation editor (Windows ▸ Animation Editor) or channel list.

The bottom left sub-pane shows the scoped channels. You can click the name of a channel to show or hide the channel in the graph display. This only changes whether the channel appears in the graph – the channel is still scoped and will be keyframed if you press K.

• When you select an object, certain parameters will be auto-scoped. These are usually the most important parameters for animation, such as translation (position), rotation, and scale. Different types of objects may have different default auto-scope lists (for example, the Dimmer parameter on lights is auto-scoped). You can customize which parameters are auto-scoped for each object (see below).

  Customizing the auto-scope parameters is especially useful when you only want to key a couple of channels (for example, Translate Y and Translate Z of a bouncing ball), since you can make sure than whenever you select and key the ball, only those channels are keyed, without paying attention to scoping the channels.

• To scope a single parameter or channel, right-click the parameter name (for all channels in the parameter, such as all translates) or an individual component (for just that channel, such as Translate Y) in the parameter editor and choose Channels and Keyframes ▸ Scope Channels.

  or

  ⇧ Shift + a parameter name or individual component in the parameter editor.

• To add a parameter or channel to the currently scoped channels, right-click the parameter name (for all channels in the parameter, such as all translates) or an individual component (for just that channel, such as Translate Y) in the parameter editor and choose Channels and Keyframes ▸ Scope Append Channels.

  or

  ⇧ Shift + a parameter name or individual component in the parameter editor.

  or

  Drag a parameter name or individual component into the scoped channel list of the animation editor or channel list pane.

• To scope all the parameters of a node, right-click the node and choose Scope channels dialog.

When you select an object, certain parameters will be auto-scoped. A list of default auto-scope parameters is set for each object type, with the parameters you usually want to animate, such as translates, rotations, and scales.

You can customize which parameters are auto-scoped for each object. This is especially useful when you only want to key a couple of channels (for example, Translate Y and Translate Z of a bouncing ball), since you can make sure than whenever you select and key the ball, only those channels are keyed, without paying attention to scoping the channels.

• Select the object you want to customize. In the parameter editor, right-click a parameter name (to set/unset auto-scope on all its channels) or a component (to set/unset auto-scope on only that channel) and choose Set autoscope or Unset autoscope.

• Select nothing, then select the object again to check whether which channels are auto-scoped.