Rigging works through the use of snapshots. A snapshot is a record of the current state of selected parameters in your project. Widgets allows you to switch between or even interpolate between stored snapshots. For example, you can create a snapshot where several text objects feature black type with a white shadow, and another snapshot that features white text with a black shadow. A checkbox widget in a rig toggles between the two states.
A checkbox widget that toggles between two states is the simplest rigging control. Slightly more complex is the pop-up menu widget, which lets you select between multiple parameter states. The slider widget offers more advanced control over multiple parameter states. For example, a slider widget lets you make gradual changes from one state to another or even use keyframes to control how the slider widget changes. You can choose which parameters are modified in the snapshot in a number of ways (described in more detail in Managing Parameter Snapshots.)
After you assign a parameter to a widget, changes you make to that parameter update the active snapshot in that widget. For example, if the parameter is assigned to a pop-up menu widget, the change is applied to the selected menu item.
Each parameter in a project can be assigned to only one widget at a time. However, you can store many values for that parameter as different snapshots that can be accessed using a pop-up menu or slider widget. (As previously noted, checkbox widgets can only save two snapshots.)
Because a parameter cannot be controlled simultaneously by two widgets, you cannot duplicate (or cut/copy and paste) a rig or widget object. Similarly, if you duplicate or copy and paste an object with rigged parameters, the new object’s parameters are not rigged.
Further, if a parameter is assigned to a widget, that parameter cannot be modified while you are recording a different widget’s snapshot. For example, if you have a slider widget controlling a shape object’s color, and you begin recording a snapshot for a different widget, the shape’s color is not modifiable.
Some parameter types cannot be rigged. Some parameters that use the mini-curve editor to affect an object over a range (such as the various “over stroke” parameters in the Shape inspector) cannot be added to a rig or modified while recording a snapshot. If you modify a parameter that cannot be rigged in edit mode, the change is applied globally—affecting all snapshots containing that object.