GyroWand

We present GyroWand, a raycasting technique for 3D interactions in self-contained Augmented Reality (AR) head-mounted displays. Unlike traditional raycasting which requires absolute spatial and ro-tational tracking of a user’s limb, GyroWand relies on the relative rotation values captured by an inertial measurement unit (IMU) on a handheld controller. However, these values cannot be directly mapped to the ray direction due to the phenomenon of sensor drift and the mismatch between the orientations of the physical controller and the virtual content. To address these challenges our approach 1) interprets the relative rotational values using a state machine; 2) handles drift by resetting initial rotation; 3) does not initiate raycasting from the users hand, but rather from on-body spatial coordinates; and 4) provides three new disambiguation mechanisms: Lock&Twist, Lock&Drag, and AutoTwist. We evaluated the performance and convenience of different GyroWand design parameters.We conclude with a summary of the lessons learned for the adoption of raycasting in mobile augmented reality head-mounted displays.