Virtual Reality (VR) applications often require users to perform actions with two hands when performing tasks and interacting with objects in virtual environments. Although bimanual interactions in VR can resemble real-world interactions -- thus increasing realism and improving immersion -- they can also pose significant accessibility challenges to people with limited mobility, such as for people who have full use of only one hand. An opportunity exists to create accessible techniques that take advantage of users' abilities, but designers currently lack structured tools to consider alternative approaches. To begin filling this gap, we propose Two-in-One, a design space that facilitates the creation of accessible methods for bimanual interactions in VR from unimanual input. Our design space comprises two dimensions, bimanual interactions and computer assistance, and we provide a detailed examination of issues to consider when creating new unimanual input techniques that map to bimanual interactions in VR. We used our design space to create three interaction techniques that we subsequently implemented for a subset of bimanual interactions and received user feedback through a video elicitation study with 17 people with limited mobility. Our findings explore complex tradeoffs associated with autonomy and agency and highlight the need for additional settings and methods to make VR accessible to people with limited mobility.

翻译：虚拟现实（VR）应用通常要求用户在虚拟环境中执行任务和与物体交互时使用双手操作。尽管VR中的双手交互能模拟现实世界交互——从而提升真实感与沉浸度——但也给行动能力受限者（例如仅能使用单手的人群）带来了显著的可及性挑战。当前存在利用用户现有能力开发无障碍技术的契机，但设计者仍缺乏系统性工具来探索替代方案。为填补这一空白，我们提出"双合一"设计空间，该空间旨在通过单手输入创建VR中双手交互的无障碍实现方法。该设计空间包含两个维度：双手交互与计算机辅助，并详细论述了创建将单手输入映射至VR双手交互的新技术时需考量的关键问题。我们应用该设计空间开发了三种交互技术，针对部分双手交互场景进行实现，并通过面向17名行动受限参与者的视频启发式研究收集用户反馈。研究结果揭示了自主性与代理权之间的复杂权衡，并强调了需要更多设置与方法以保障行动受限人群无障碍使用VR的必要性。