Rear-Screen and Kinesthetic Vision 3D Manipulator

本研究探討以背螢幕手部體感互動方法，增進對虛擬三維物件操作之直覺性與效率。虛擬三維物件之操作共可分為三面向去探討：呈現面、控制面與該兩面向之空間耦合問題，其中又以第三項最具困難性：傳統體感操作之互動範圍於螢幕前側，而實際上使用者對於虛擬物件之空間感知位置於螢幕後側。因此，在操作過程中由於使用者需將操作與感知空間於腦中耦合，進而造成手眼協調的不易與負擔。 本研究提出「背螢幕式三維物件互動法」使體感操作與物件空間位置一致以克服以上困難；目的為使使用者猶如將手探入螢幕後方之虛擬環境進行直接操作。該方法共分為「背螢幕互動」與「動覺視覺」：前者即將體感裝置設置於螢幕後方進行感測，以利達成前述之空間耦合。後者藉由頭部動態追蹤來改變虛擬環境中使用者視角，增進虛擬環境之真實感，並可藉由視角變化所產生之「運動視差效果」，協助使用者感知一般平面顯示器較難傳達之空間深度訊息。 為驗證本設計方法，本研究設計使用者測試實驗以量化結果並比前後螢幕設置之表現差異。實驗共三種設置：傳統前螢幕式操作、背螢幕式操作與背螢幕式加上視角追蹤。每種設置情形下，使用者須抓取虛擬物件由一開始位置移動至一隨機位置，單組試驗須共移動二十次，一情境須進行五組試驗。經由十二位受測者測試並以變異數分析結果後顯示，背螢幕式設置能增進空間深度方向 24% 之移動效率。The effective 3D manipulation, comprehension, and control of 3D objects on computers are well-established lasting problems, which include a display aspect, a control aspect, and a space coupling between control input and visual output aspect, which is a debatable issue. Most existing control interfaces are located in front of the display. This requires users to imagine that manipulated objects that are actually behind the display exist in front of the display. In this research, the Rear-Screen and Kinesthetic Vision 3D Manipulator is proposed for manipulating models on laptops. In contrast to the front-screen setup of a motion controller, it tracks a user’s hand motion behind screens, coupling the actual interactive space with the perceived visual space. In addition, Kinesthetic Vision provides a dynamic perspective of objects according to a user’s sight, by tracking the position of their head, in order to obtain depth perception using the “motion parallax” effect. To evaluate the performance of “rear-screen interaction” and Kinesthetic Vision, an experiment was conducted to compare the front-screen setup, the rear-screen setup with Kinesthetic Vision, and the rear-screen setup without it. Subjects were asked to grasp and move a cube from a fixed starting location to a target location in each trial. There were 20 designated target locations scattered in the interactive space. The moving time and distance were recorded during experiments. In each setup, subjects were asked to go through 5 trial blocks, including 20 trials in each block. The results show that there are significant differences in the moving efficiency by repeated measures ANOVA. The Rear-Screen and Kinesthetic Vision setup gives rise to better performance, especially in the depth direction of movements, where path length is reduced by 24%