The present invention provides haptic sensations for a haptic feedback
device and especially for a rotational device such as a knob. Force
effects such as a hill force effect and barrier force effect allow easier
selection of menu items, menus, values, or other options by the user.
Force models are also described to allow greater selection functionality,
such as a scrolling list with detents and rate control borders, a jog
shuttle, a push-turn model, a double-push model, and a cast control
model.