Simulation - Animating with Blender: How to Create Short Animations from Start to Finish - page 259

Actor button, you will also need to enable the Bounds button and choose the closest shape to that of your
object in the drop-down that appears. The normal options are: box, sphere, cylinder, and cone. This tells the
simulation how best to calculate collisions involving your objects. For stationary objects, (your set), these set-
tings are suffi cient.
Figure 14.33 Enabling objects as Actors and setting their Bounds
For objects that will move—in this case, the canisters—you need to enable both the Dynamic and Rigid
Body buttons to the right of the Actor button. Figure 14.34 shows the settings for the canisters. Dynamic
tells the simulator that the object should be affected by things such as gravity and move when struck by other
objects. The Rigid Body setting allows the object to tumble and roll realistically. The Bounds object that
most closely matches their shapes is obviously the Cylinder .
Figure 14.34 Preparing objects for rigid body motion
At any point you can test your simulation by hovering the mouse over the 3D view and pressing the P key.
This command starts the physics engine and will continue it until you press the Esc key. Of course, pressing
the P key at this point won't do very much. Well, it shouldn't.
It's possible that if you are following along with this setup that activating the physics engine will cause the
canisters to rapidly fl y away, as though from an explosion. If that happens, it just means that the objects were
considered to be in a state of collision at the very beginning of the physics simulation. To fi x the problem,