I can't speak to the precise target size required for tracking, but it will depend on both the device and the target. Targets with stronger features will be easier to track from a distance. You'll probably find that once you get a lock on the target you can pull the camera back quite a bit, but to initially detect the target you may need more of it in view.

As to your second question, this should be pretty easy. Use one trackable to set up the modelview matrix (using its pose), and ignore the pose of the other trackables, using them to switch your animation logic instead. You'll want to use the Trackable::getName() method to identify the trackables.

- Kim

In addition to the above, is it possible to track one target for position and rotation information, and use a second target to trigger an animation to occur?

What I would like to do, is use a static billboard to use for tracking position and rotation. Next to the billboard there is a video screen, and I want to trigger an animation to occur whenever a certain image appears on the video screen. Does that make sense? I am also hoping that the animation would be in-sync with what is happening on the screen.