I've this application, where two children are playing catch. One throws and the other catches. While I can show a ball object moving between two stationary objects, how do I show the objects "releasing" and "catching" the ball, in a way that is close to lifelike?
EDIT: The movement of the hands in this game: http://www.acreativedesktop.com/animation-game-slaphands.html is what I would like to replicate. Any tips on how to do that?
skeletal animation is a good technique
also reverse kinematics
or even motion-capture
I know this is essentially possible in flash... it does however sound pretty complex. My advice would be to create static animations for the throw action and the catch action, then have these actions play when certain conditions are met (i.e. the ball gets close to one of the people). Trying to get a lifelike throw and catch will be pretty tough. I would think even a lot of console games wouldn't attempt to do this dynamically (i do expect this is in the process or is changing in current gen games)
As it's already been stated, you need animation to get it right. I suggest looking over Preston Blair's Cartoon Animation Book or The Animator's Survival Kit. You won't need to read the whole thing, just reference the chapters on anticipation and accents.
For example, when one throws, the action doesn't just happen, one first prepares, anticipating the throw, building up energy. In animation you prepare the viewer for the next action, thus creating a seamless link between actions. Once the ball is thrown...there is action and re-action, so the player will return to his casual pose.
The actionscript part should be pretty simple. You should get away with 3 vectors: 1 for setting the balls movement 1 for gravity 1 for friction/wind...etc. Based on your parameters, you launch the ball, then use the distance between the ball and the catcher to figure out when you can you play the catcher's animation(s)