Surface visualizations are essential in analyzing three-dimensional spatiotemporal phenomena. Given its ability to provide enhanced spatial perception and scene maneuverability, virtual reality (VR) is an essential medium for surface visualization and interaction tasks. Such tasks primarily rely on visual cues that require an unoccluded view of the surface region under consideration. Haptic force feedback is a tangible interaction modality that alleviates the reliance on visual-only cues by allowing a direct physical sensation of the surface. In this paper, we evaluate the use of a force-based haptic stylus compared to handheld VR controllers via a between-subjects user study involving fundamental interaction tasks performed on surface visualizations. Keeping a consistent visual design across both modalities, our study incorporates tasks that require the localization of the highest, lowest, and random points on surfaces; and tasks that focus on brushing curves on surfaces with varying complexity and occlusion levels. Our findings show that participants took longer to brush curves using the haptic modality but could draw smoother curves compared to the handheld controllers. In contrast, haptics was faster in point localization, but the accuracy depended on the visual cues and occlusions associated with the tasks. Finally, we discuss participant feedback on using haptic force feedback as a tangible input modality and share takeaways to help outline design strategies for using haptics-based tangible inputs for surface visualization and interaction tasks.

翻译：表面可视化在分析三维时空现象中至关重要。鉴于其提供增强空间感知和场景操控能力的特点，虚拟现实（VR）已成为表面可视化及交互任务的重要媒介。此类任务主要依赖视觉线索，需要对所考察表面区域保持无遮挡的视野。触觉力反馈作为一种实体交互模态，通过允许直接物理感知表面形态，减轻了对纯视觉线索的依赖。本文通过一项被试间用户研究，评估了基于力反馈的触觉笔相较于手持VR控制器在表面可视化基础交互任务中的表现。研究在保持两种交互模式视觉设计一致的前提下，设计了以下任务：在表面定位最高点、最低点及随机点；在不同复杂度与遮挡程度的表面上绘制曲线。研究结果表明：使用触觉模态绘制曲线耗时更长，但相比手持控制器能绘制更平滑的曲线；反之，触觉模态在点定位任务中速度更快，但其准确性取决于任务相关的视觉线索与遮挡程度。最后，我们讨论了参与者对触觉力反馈作为实体输入模态的反馈，并分享研究启示，以期为基于触觉的实体输入在表面可视化及交互任务中的设计策略提供参考。