I have the need for some time based effects in the iPad app I am building. The UIView class animation capability beginAnimatins/commitAnimations is exactly the sort of thing I am looking for but it is restricted to specific properties of UIView deemed animatable.

Ideally, I am looking for a solution that lets me drive an a time-based function that can perhaps send messages to a class of my own choosing at the rate I specify in the animation.

Specifically, I have a function - my implementation of the RenderMan function "smoothstep" which is essentially an ease-in ease-out curve common in animation. It takes [0 - 1] as input and outputs [0 - 1] as the curve is evaluated. I want to drive this function for a duration of my own choosing at rate of my own choosing.

Thanks in advance.

-Doug