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Investigating Bubble Mechanism for Ray-Casting to Improve 3D Target Acquisition in Virtual Reality

Ray-casting, i.e., a ray cast from a hand-held controller to select targets, is widely used in 3D environments. Inspired by the bubble cursor [12] which dynamically resizes its selection range on 2D surfaces, we investigate a bubble mechanism for ray-casting in virtual reality. Bubble mechanism identifies the target nearest to the ray, with which users do not have to accurately shoot through the target. We first design the criterion of selection and the visual feedback of the bubble. We then conduct two experiments to evaluate ray-casting techniques with bubble mechanism in both simple and complicated 3D target acquisition tasks. Results show the bubble mechanism significantly improves ray-casting on both performance and preference, and our Bubble Ray technique with angular distance definition is competitive compared with other target acquisition techniques. We also discuss potential improvements to show more practical implementations of ray-casting with bubble mechanism.