Ballistic Trajectory

Ballistic Trajectory tool is used to calculate physically accurate trajectories for characters in the state of free flight. Using it enables  animating realistic jumps, flights and other moves that require your character to get off the ground. Ballistic trajectories can be adjusted somewhat like regular trajectories, but they are created differently and serve different purpose.

Controls

Ballistic trajectory can be created and managed using the dedicated set of buttons on the Timeline:

(1) Ballistic trajectory

This button adds a ballistic trajectory to the current scene.

(2) Snap centers of mass to selected trajectory

Pressing this button makes the character move so its center of mass is always aligned with the trajectory of the ballistic curve.

For this button to work properly, an interval on the Timeline should be selected beforehand. If you select a part of the interval on the timeline, the center of mass will snap to the curve only on the selected frames.

(3) Set physics priority frame

This button selects frames that should be taken into account for calculating the object’s rotation during ballistic movement.

A selected frame is marked with a red flag

Multiple frames can be marked at once, but the more positions are used for calculating rotation, the harder it becomes to take them all into account. It is recommended to mark no more than 3 or 4 frames for one ballistic trajectory.

Ballistic Trajectory Structure

(1) Impulse Point

This point controls the impulse that is applied to the object at the start of its ballistic movement. It should coincide with object's center of mass

By moving Impulse point you can adjust every parameter of the ballistic curve: its length, its height, its direction, and its frame count (the number of frames that the object would spend travelling this trajectory)

Note: The length of a ballistic trajectory is represented on the Timeline as a black line

(2) First Frame of the Ballistic Curve

This should be the last frame where the object is still on the ground

Moving this point adjusts the distance of ballistic movement without changing its frame count

(3) Point of Height

This point defines the maximum height of the ballistic movement (and subsequently its frame count). It can only be move up and down.

(4) Landing Point

The last frame of ballistic movement and the frame where the object touches the ground. This point can be used to adjust the distance of the ballistic movement without affecting its framecount

Grey dots on the ballistic curve represent frames. The current frame is marked with a circle.

 

See Also

Ballistic Ghosts

Fulcrum Points

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