Simple Kinematics

The Simple Kinematics modifier applies a constant acceleration to a channel. Use this to produce a physically based trajectory for something flying or falling through the air and taking gravity into account. (This is much like a Gravity modifier but without bouncing.) To create a trajectory for a thrown ball, you apply the modifier to the ball, link the modifier's Output to the ball's Y-position channel, and set the proper options.

For example, if you set the Starting Position to the Y value that the ball should start moving from, leave the Starting Time at 0.0. For acceleration (meters per second), type 9.8 (for Earth). Set the Starting Speed to 22 (meters per second), which would be a 50 mph baseball throw. For something more interesting than a vertical throw, add a constant velocity along the ground by either setting a linear enveloped motion on the X channel or by adding another Simple Kinematics modifier with a constant speed and no acceleration on the X channel.

Other uses for this type of constant velocity/constant acceleration include buoyant objects accelerating upwards, possibly cars and vehicles, and any other process where the resulting channel shape should be linear or parabolic.