Department of Computer Science, University of Münster, Münster, Germany.
IEEE Trans Vis Comput Graph. 2010 Jan-Feb;16(1):17-27. doi: 10.1109/TVCG.2009.62.
In immersive virtual environments (IVEs), users can control their virtual viewpoint by moving their tracked head and walking through the real world. Usually, movements in the real world are mapped one-to-one to virtual camera motions. With redirection techniques, the virtual camera is manipulated by applying gains to user motion so that the virtual world moves differently than the real world. Thus, users can walk through large-scale IVEs while physically remaining in a reasonably small workspace. In psychophysical experiments with a two-alternative forced-choice task, we have quantified how much humans can unknowingly be redirected on physical paths that are different from the visually perceived paths. We tested 12 subjects in three different experiments: (E1) discrimination between virtual and physical rotations, (E2) discrimination between virtual and physical straightforward movements, and (E3) discrimination of path curvature. In experiment E1, subjects performed rotations with different gains, and then had to choose whether the visually perceived rotation was smaller or greater than the physical rotation. In experiment E2, subjects chose whether the physical walk was shorter or longer than the visually perceived scaled travel distance. In experiment E3, subjects estimate the path curvature when walking a curved path in the real world while the visual display shows a straight path in the virtual world. Our results show that users can be turned physically about 49 percent more or 20 percent less than the perceived virtual rotation, distances can be downscaled by 14 percent and upscaled by 26 percent, and users can be redirected on a circular arc with a radius greater than 22 m while they believe that they are walking straight.
在沉浸式虚拟环境 (IVE) 中，用户可以通过移动跟踪头部并在现实世界中行走来控制虚拟视点。通常，现实世界中的运动被一一映射到虚拟相机运动。通过重定向技术，通过对用户运动施加增益来操纵虚拟相机，使得虚拟世界的运动与现实世界不同。因此，用户可以在物理上仍留在相对较小的工作空间中穿行大规模的 IVE。在使用二选一强制选择任务的心理物理学实验中，我们已经量化了人类在与视觉感知路径不同的物理路径上无意识地被重定向的程度。我们在三个不同的实验中测试了 12 个受试者：（E1）在虚拟和物理旋转之间进行区分，（E2）在虚拟和物理直线运动之间进行区分，以及（E3）区分路径曲率。在实验 E1 中，受试者以不同的增益进行旋转，然后必须选择视觉感知的旋转是否小于或大于物理旋转。在实验 E2 中，受试者选择物理行走的距离是短于还是长于视觉感知的缩放旅行距离。在实验 E3 中，当受试者在现实世界中沿着弯曲的路径行走时，视觉显示器显示虚拟世界中的直线路径，他们估计路径的曲率。我们的结果表明，用户可以被物理旋转大约 49%以上或 20%以下，距离可以缩小 14%，放大 26%，并且当他们认为自己在直走时，用户可以在半径大于 22 米的圆弧上被重定向。
