Ballistic trajectory

When a character is in the air during the jump or fall, his center of mass always moves strictly along a ballistic curve, regardless of what movements the character makes in flight.
The shape of the ballistic curve depends on the speed of the Center of Mass, and on its direction right before the jump.

For example, trajectory of a ball jumping would depend on the force used to throw it and on how the arm was moving before throwing it.
But in any case a ballistic trajectory is always shaped like an arch across which the speed changes gradually.



By simply following a ballistic trajectory you can greatly improve realism of your animation!

For example, in The Matrix movie all the stunts are masterfully crafted… but speed-ups and trajectories of the jumps betray the fact that the actor was supported by wires.


 

The physics corrector automatically creates ballistic trajectories for the center of mass if there are no fulcrums in the frame interval. 

• Open the Simple model scene from the samples.
• Create keys in frames 10, 15, 20 and 30
• Set Bezier Clamped interpolation
• Go to frame 15
• Select the pelvis point of the character and raise it above the ground. You can also lift the character's legs.
• Turn on AutoPhysics

The height of a jump depends only on its time! Two characters jumping at different distances but reaching the same height would spend the same amount of time in the air.



So if you want to increase or decrease the height of your ballistics, you’ll also need to increase or decrease the number of frames in the ballistic interval.
You can also change the force of gravity, but we’ll talk about this later.

• Go to frame 10
• Press the + button to add new frames.
• Go to frame 15
• Add new frames after frame 15