Fribourg Rebecca, Argelaguet Ferran, Lecuyer Anatole, Hoyet Ludovic
IEEE Trans Vis Comput Graph. 2020 May;26(5):2062-2072. doi: 10.1109/TVCG.2020.2973077. Epub 2020 Feb 13.
In Virtual Reality, a number of studies have been conducted to assess the influence of avatar appearance, avatar control and user point of view on the Sense of Embodiment (SoE) towards a virtual avatar. However, such studies tend to explore each factor in isolation. This paper aims to better understand the inter-relations among these three factors by conducting a subjective matching experiment. In the presented experiment ( n=40), participants had to match a given "optimal" SoE avatar configuration (realistic avatar, full-body motion capture, first-person point of view), starting by a "minimal" SoE configuration (minimal avatar, no control, third-person point of view), by iteratively increasing the level of each factor. The choices of the participants provide insights about their preferences and perception over the three factors considered. Moreover, the subjective matching procedure was conducted in the context of four different interaction tasks with the goal of covering a wide range of actions an avatar can do in a VE. The paper also describes a baseline experiment ( n=20) which was used to define the number and order of the different levels for each factor, prior to the subjective matching experiment (e.g. different degrees of realism ranging from abstract to personalised avatars for the visual appearance). The results of the subjective matching experiment show that point of view and control levels were consistently increased by users before appearance levels when it comes to enhancing the SoE. Second, several configurations were identified with equivalent SoE as the one felt in the optimal configuration, but vary between the tasks. Taken together, our results provide valuable insights about which factors to prioritize in order to enhance the SoE towards an avatar in different tasks, and about configurations which lead to fulfilling SoE in VE.
在虚拟现实领域，已经开展了多项研究来评估虚拟形象外观、虚拟形象控制以及用户视角对虚拟形象的具身感（SoE）的影响。然而，此类研究往往孤立地探究每个因素。本文旨在通过进行一项主观匹配实验，更好地理解这三个因素之间的相互关系。在所示实验（n = 40）中，参与者必须从“最小化”具身感配置（极简虚拟形象、无控制、第三人称视角）开始，通过逐步增加每个因素的水平，来匹配给定的“最优”具身感虚拟形象配置（逼真虚拟形象、全身动作捕捉、第一人称视角）。参与者的选择为我们提供了他们对所考虑的这三个因素的偏好和认知方面的见解。此外，主观匹配过程是在四种不同交互任务的背景下进行的，目的是涵盖虚拟形象在虚拟环境中所能进行的广泛动作。本文还描述了一个基线实验（n = 20），该实验用于在主观匹配实验之前确定每个因素不同水平的数量和顺序（例如，视觉外观方面从抽象到个性化虚拟形象的不同逼真程度）。主观匹配实验的结果表明，在增强具身感方面，用户在提升外观水平之前，会先持续提高视角和控制水平。其次，我们确定了几种具身感与最优配置中所感受到的具身感相当的配置，但这些配置在不同任务之间存在差异。综合来看，我们的研究结果为在不同任务中增强对虚拟形象的具身感时应优先考虑哪些因素，以及在虚拟环境中实现具身感的配置提供了有价值的见解。
