Android :: How To Use Information From Sensor For Augmented Reality?

Could somebody (Mathias Agopian alias pixelflinger perhaps) please tell me how to use information from sensor for augmented reality stuff. Sorry am not much into graphics stuff but I did try my part to figure stuff out with help of documentation. Didn't miss the note: ""Note: It is preferable to use getRotationMatrix() in conjunction with remapCoordinateSystem() and getOrientation() to compute these values; while it may be more expensive, it is usually more accurate. Tried both. With the above method roll is always negative (in radians) of the roll returned by orientation sensor event. Not the real problem though as these are in the same +/-90 range but negative/opposite. One of these goes against the definition of roll in android documentation. I have the camera on landscape mode and did try with and without the suggestion: ""# Using the camera (Y axis along the camera's axis) for an augmented reality application where the rotation angles are needed : remapCoordinateSystem(inR, AXIS_X, AXIS_Z, outR); Yet no luck. Got a few lessons on quaternions etc. But am sure it is much easier than the mess am getting into. Say, orientation sensor event returns yaw, pitch & roll in say eO[] What are the next steps to get rotation matrix that I could use in opengl to rotate a augmented scene overlapping the camera preview?