FocalSelect: Improving Occluded Objects Acquisition with Heuristic Selection and Disambiguation in Virtual Reality

In recent years, various head-worn virtual reality (VR) techniques have emerged to enhance object selection for occluded or distant targets. However, many approaches focus solely on ray-casting inputs, restricting their use with other input methods, such as bare hands. Additionally, some techniques speed up selection by changing the user's perspective or modifying the scene context, which may complicate interactions when users plan to resume or manipulate the scene afterward. To address these challenges, we present FocalSelect, a heuristic selection technique that builds 3D disambiguation through head-hand coordination and scoring-based functions. Our interaction design adheres to the principle that the intended selection range is a small sector of the headset's viewing frustum, allowing optimal targets to be identified within this scope. We also introduce a density-aware adjustable occlusion plane for effective depth culling of rendered objects. Two experiments are conducted to assess the adaptability of FocalSelect across different input modalities and its performance against five selection techniques. The results indicate that FocalSelect enhances selection experiences in occluded and remote scenarios while preserving the spatial context among objects. This preservation helps maintain users' understanding of the original scene and facilitates further manipulation. We also explore potential applications and enhancements to demonstrate more practical implementations of FocalSelect.