CMAttitudeReferenceFrame
Constants that indicate the frame of reference for attitude-related motion data.
Declaration
struct CMAttitudeReferenceFrameOverview
When you start a service that reports the device’s attitude in three-dimensional space, Core Motion establishes a frame of reference for reporting pitch, roll, and yaw values. All subsequent data values specify the device attitude relative to this frame of reference. To get a list of the currently available reference frames for the current device, call the availableAttitudeReferenceFrames() class method.
When starting services, it’s your responsibility to specify a reference frame that’s available on the current device. Services that don’t let you specify a reference frame explicitly rely on the value in the attitudeReferenceFrame property of CMMotionManager.