3

Chapter 5 Using Behaviors 429
The Throw behavior is also useful when you’re moving an object through a simulation.
For example, you might move the object past other objects that have Attractor or
Repel behaviors applied to them. Because the Throw behavior only applies a single
force to move the target object at the initial frame of the behavior, any other behaviors
that interact with the target object have potentially greater influence over its motion.
Important: The Throw behavior does not apply a continuous force, nor can you create
changes in direction or speed, since this behavior cannot be keyframed. If you need to
create keyframed changes in direction or speed, use the Wind behavior. If you need to
create a more complex animation path, use the Motion Path behavior.
HUD Control
The 2D HUD lets you specify the direction and speed of the Throw behavior by
dragging an arrow within a circular region. The direction of the arrow defines the
direction of movement in X and Y space, and the length of the arrow defines speed
(velocity). A slider to the right lets you adjust the scale of the HUD control, increasing or
decreasing the effect the direction/speed control has over the object.
When you click the 3D button, additional 3D controls become available. The center
arrow now defines the direction the object is thrown in 3D space (X, Y, and Z axes). The
Speed slider (on the left side of the HUD) lets you increase or decrease the velocity of
the thrown object.
Controls direction and speed of Throw.
Adjusts scale of the direction and
speed control.
Adjusts velocity of the
throw.
Adjusts the direction of
the throw in X, Y, and Z.