HeadCross

Abstract

We propose HeadCross, a head-based interaction method to select targets on VR and AR head-mounted displays (HMD). Using HeadCross, users control the pointer with head movements and to select a target, users move the pointer into the target and then back across the target boundary. In this way, users can select targets without using their hands, which is helpful when users' hands are occupied by other tasks, e.g., while holding the handrails. However, a major challenge for head-based methods is the false positive problems: unintentional head movements may be incorrectly recognized as HeadCross gestures and trigger the selections. To address this issue, we first conduct a user study (Study 1) to observe user behavior while performing HeadCross and identify the behavior differences between HeadCross and other types of head movements. Based on the results, we discuss design implications, extract useful features, and develop the recognition algorithm for HeadCross. To evaluate HeadCross, we conduct two user studies. In Study 2, we compared HeadCross to the dwell-based selection method, button-press method, and mid-air gesture-based method. Two typical target selection tasks (text entry and menu selection) are tested on both VR and AR interfaces. Results showed that compared to the dwell-based method, HeadCross improved the sense of control; and compared to two hand-based methods, HeadCross improved the interaction efficiency and reduced fatigue. In Study 3, we compared HeadCross to three alternative designs of head-only selection methods. Results show that HeadCross was perceived to be significantly faster than the alternatives. We conclude with the discussion on the interaction potential and limitations of HeadCross.

Radi-Eye: Hands-Free Radial Interfaces for 3D Interaction using Gaze-Activated Head-Crossing

“…Crossing relaxes the constraint on fine-grained pointing within a closed area as the user only has to cross the target boundary. As such, researchers have proposed crossing for users with limited motor capabilities [45], and for a wide array of modalities with limited fine-grained pointing or where the modality lacks an explicit confirmation mechanism [6,23,44,48]. More recently, researchers have shown that crossing can be effectively used in 3D environments by ray-casting with a controller [43], or for hands-free selection via the head [47,48].…”

“…As such, researchers have proposed crossing for users with limited motor capabilities [45], and for a wide array of modalities with limited fine-grained pointing or where the modality lacks an explicit confirmation mechanism [6,23,44,48]. More recently, researchers have shown that crossing can be effectively used in 3D environments by ray-casting with a controller [43], or for hands-free selection via the head [47,48]. Finally, crossing also allows selection of multiple targets in a single user input [2,41], allowing fast and expressive user interfaces.…”

“…Hands-free interaction is widely studied for 3D interaction in headmounted displays (HMDs) to support contexts in which the hands are unavailable, occupied, or where space, ability or fatigue constrain their use [27,29,37,46,48]. Gaze and head are attractive alternatives to manual input, as their movement can be tracked with built-in sensors without needing additional devices.…”

Emerging ExG-based NUI Inputs in Extended Realities: A Bottom-up Survey

“…For example, Microsoft Hololens employs head pointing to target a user-interested item, and subsequently, a touch-based clicker enables users to confirm the target selection. Although it is preferred by users [219], head pointing is not ergonomic for long-term usage. Alternatively, eye pointing achieves more subtle movements than the head pointing, which also serves as an alternative solution for pointing and selecting an attentive target after a predefined duration of time (i.e., dwell time) [174].…”

The First Workshop on Multiple Input Modalities and Sensations for VR/AR Interactions (MIMSVAI)

“…Existing studies incorporate a wide range of input modalities (e.g., eye gaze [5], gesture [10], and voice [7]) to sense users' actions so that they can interact with virtual/augmented content as easily as they interact with the real world around them. Besides providing easy-to-use input modalities, many researchers explored ways to enhance realism in the VR/AR world to improve the level of immersiveness.…”