Using virtual reality setups, users can fade out of their surroundings and dive fully into a thrilling and appealing virtual environment. The success of such immersive experiences depends heavily on natural and engaging interactions with the virtual world. As developers tend to focus on intuitive hand controls, other aspects of the broad range of full-body capabilities are easily left vacant. One repeatedly overlooked input modality is the user's gait. Even though users may walk physically to explore the environment, it usually does not matter how they move. However, gait-based interactions, using the variety of information contained in human gait, could offer interesting benefits for immersive experiences. For instance, stealth VR-games could profit from this additional range of interaction fidelity in the form of a sneaking-based input modality. In our work, we explore the potential of sneaking as a playful input modality for virtual environments. Therefore, we discuss possible sneaking-based gameplay mechanisms and develop three technical approaches, including precise foot-tracking and two abstraction levels. Our evaluation reveals the potential of sneaking-based interactions in IVEs, offering unique challenges and thrilling gameplay. For these interactions, precise tracking of individual footsteps is unnecessary, as a more abstract approach focusing on the players' intention offers the same experience while providing better comprehensible feedback. Based on these findings, we discuss the broader potential and individual strengths of our gait-centered interactions.

翻译：利用虚拟现实设备，用户能够脱离现实环境，全身心沉浸于扣人心弦、引人入胜的虚拟世界。此类沉浸式体验的成功，很大程度上取决于与虚拟世界自然且富有吸引力的交互。由于开发者往往聚焦于直观的手部操控，人体全身能力中其他方面的丰富可能性便容易被忽视。其中，一个常被忽略的输入模态是用户的步态。尽管用户可能会通过实际行走来探索环境，但其移动方式通常无关紧要。然而，基于步态的交互——利用人类步态中蕴含的多样化信息——可为沉浸式体验带来有趣的增益。例如，潜行类VR游戏便可通过基于潜行步态的输入模态，从这种额外的交互保真度中获益。本研究探索了将潜行作为虚拟环境中趣味性输入模态的潜力。为此，我们讨论了可能的潜行类游戏机制，并开发了三种技术方案，包括精确足部追踪及两种抽象层级。评估结果表明，基于潜行的交互在沉浸式虚拟环境中具有潜力，能提供独特的挑战与扣人心弦的游戏体验。对于此类交互，精确追踪单个脚步并非必要；相反，一种更注重玩家意图的抽象方法能在提供相同体验的同时，带来更易于理解的反馈。基于这些发现，我们进一步讨论了这种以步态为核心的交互的广泛潜力及其各自的优势。