That sounds harder than Dustin's way to me, to be honest!
"Say you're hanging from a huge cliff at the top of mt. everest and a guy comes along and says he'll save you, and proceeds to throw religious pamphlets at you while simultaniously giving a sermon." - Dustin G
OK here's a reasonably easy way I used to use way back. Set the ball to a platform movement and set Speed, Acc, Dec to 0 and set it to No Jump. Then set the gravity you want. Then in the event editor...
Use the balls alterable value A as the trigger for jumping/falling, and Alt B as the strength of jump.
Ball Alt Value A = 1
+Ball Alt Value B > 0
Ball - Movement - Stop
Ball - Position - Y Coordinate - Y( "Ball" ) - Value B( "Ball" )
Ball - Values - Subtract 1 from B
Ball Collides with Backdrop
Ball - Movement - Stop
Ball - Values - Set A to 0
The platform movement will sort out the gravity for itself. It's a very simple way, to make it jump/bounce simply set Alt A to 1, and set Alt B to a variable depending on how high you want it to go.
Show me the power child,
I'd like to say,
That I'm down on my knees today,
Gives me the butterflies,
Gives me away,
'Til I'm up on my feet again,
I'm feeling outshined.
Depends on which way this ball is suppose to react.
If it is simply shot by another object, which means it won't be able to bounce or anything, these are the only events you'll need.
Set Y of Ball to Y("Ball") + Alterable Value A("Ball")
- Every 0"00'05 (this delay can be changed to make ball fall at faster or slow rate)
+ Alterable Value A of Ball < 20(this value determines terminal velocity of ball)
Add 1 to Alterable Value A of Ball
That's simple enough for a non-reactive projectile. As for something that bounces you may want to add some other events for collisions. I recommend something along the lines of...
- Ball collides with obstacle
Set Alterable Value A to -1
Set Speed of Ball to Speed("Ball") / 2
You may want to change the value the ball is decreased by, but this event essentially makes the ball bounce, lose half its speed, and changes the Alterable Value A (which is the vertical velocity causing it to fall) to a negative value thus making it go upwards for just a bit.
Of course these values may need a bit of tweaking depending on your desired effect, and you may find that sometimes there are a few odd bounces that occur. But I recommend you give that a try.