… for Apple Motion
Tip #750: What Are Simulation Behaviors?
Simulation behaviors are very simple ways to create complex motion.
The following text is from the Apple Motion Help files.
Simulation behaviors perform one of two tasks. Some Simulation behaviors, such as Gravity, animate the parameters of an object in a way that simulates a real-world phenomenon. Other Simulation behaviors, such as Attractor and Repel, affect the parameters of objects surrounding the object to which they’re applied. These behaviors allow you to create sophisticated interactions among multiple objects in your project with minimal adjustments. Like the Basic Motion behaviors, Simulation behaviors also affect specific object parameters. Examples include Attractor, Gravity, and Repel.
Important: Several Simulation behavior parameters contain object wells into which you drag target objects used as attractors, repellers, orbiters, and so on. Dragging an object to a well can be tricky—be sure to drag the object name (or thumbnail) from the Layers list to the object well in the Inspector without releasing the mouse button until the pointer is over the object well. If you click the object in the Layers list and release the mouse button, that behavior object is deselected its parameters are no longer displayed in the Inspector. This applies to all object wells, including mask source wells and image wells.