What I'm trying to accomplish is keeping in-game gravity [approximately] aligned with actual gravity, regardless of camera or ImageTarget orientation. It seems like it should be a simple feature to implement -- the Input.acceleration values should give you the direction of gravity in local space, and TransformDirection() should transform the direction to world space. So far, the best I've been able to come with as far as getting the direction is:
Camera.main.transform.TransformDirection ( Input.acceleration )
This is producing the wrong direction, and I'm not entirely sure why. Any insight?