I'll be honest; I had absolutely no idea how to even begin approaching this one! I think I was so wrapped up in wanting to make something impressive and amazing and perfect that I just flailed around, trying to think of the cleverest, easiest way to animate the ball. I also thought it might be a nice idea to practice with some of Softimage's other animation tools... probably a mistake, considering I'm still not all that proficient or confident with keyframes!
In this first example, I tried using the Create Curve tool to draw a path for the ball to follow:
Underneath the Create > Curve section of the Animate mode, there are a series of options that allow you to create curves or paths in different ways. I chose "Draw Cubic by Knot Points"... mostly because that's the only one I could find a tutorial for.
It works in a similar, albeit slightly more baroque, manner to Photoshop's pen tool. It's a little different; the pen tool allows you to adjust the curve/handles of the path after making two connecting points, but Softimage only allows you to manipulate the curve after placing the third - and the curve is set automatically depending on the position of the knot points. Here, for example, the depth/angle of the curve is drawn from the first and third points in the direction of the second. It's almost like the second point is a magnetic field and pulls the curve towards it, outwards from the knot at either end. That's a horrible analogy but it's the best way I can think to describe it, because it's really weird when you first use it!
The knots can be manipulated with the translate tool; use the 'Point Selection' mode (shortcut: T) to select the desired knot and then the translate tool to manipulate the curve.
Once I'd figured out roughly how the tool worked, I was able to trace a rough path of the ball's intended route down the slide and across the table:
First big mistake was not really planning how I wanted it to move; I just kind of went with the general flow of how I thought it might naturally progress down the table. I didn't think it too likely that the ball would travel through all of the rings on its course, so I had it bypass a few.
To attach the ball to the path, I selected the ball and used the 'Set Path' property found under the 'Path' section of the 'Create' menu. This locks the object to the beginning of the path and animates it along the curve drawn using the cubic knot tool... thingy. (That's the technical term!)
This will bring you into 'pick' mode; simply click on the path you want to lock the object to, and the object will then snap to the first knot on the curve.