Wow, thanks for the visuals! I appreciate your help on the ball size based on the Z axis. Like I had stated, I wasn't even to that point yet as I was trying to figure out a formula for converting the ball's actual X,Y,Z coordinates (i.e. inches) with the SCREEN coordinates of X and Y (i.e. pixels).
A friend of mine gave me some insight with the following code. This is assuming a room like your image, in an 800x600 screen resolution, but would work on other resolutions as well.
Note this is only for the Y location of the ball and does not take into account gravity, friction, etc.
parameters xreal,yreal,zreal
courtdeepreal=479
courthighreal=239
courtwidereal=239
backwallheighthinpixels=200
screenheightinpixels=599
heightbase=(courtdeepreal-zreal)*(backwallheighthinpixels/courtdeepreal)
updownrange=screenheightinpixels-(2*heightbase)
pixely=screenheightinpixels - ( heightbase + ( updownrange * (1-(yreal/courthighreal)) ) )
return pixely
Thanks again!
-Kevin