Plays an animation without any blending.
If no name is supplied then the default animation will be played. In cases where the animation can't be played
(ie, there is no default animation or no animation with the specified name), the function will return false.
The optional playMode
lets you choose how this animation will affect others already playing.
If the specified animation is already playing then other animations will be stopped but the animation will not rewind to the beginning.
When the end of the animation is reached it will automatically be stopped and rewound to the start unless the PlayMode is set to Loop.
Note that if you call Animation.Play on an object during a frame update where the object is also deactivated then the call will effectively be cancelled; the animation will not start playing when the object is later reactivated. However, if you make the call on a subsequent frame (ie, while the object is still inactive) then the animation will start playing after reactivation.