Force Arrow 2: a Novel Pseudo-Haptic Interface for Weight Perception in Lifting Virtual Objects

Weight perception of virtual objects during manipulating them in an immersive virtual reality (VR) environment can increase a sense of presence in the VR environment of a user. Conventional researches used haptic interfaces which pressed a user's fingers or hands to express weights of the virtual objects. Due to their technical complexities of the haptic interfaces, the weight perception has been regarded as one of difficult issues to be applied in an immersive VR environment. In this paper, a pseudo-haptic interface, called "Force Arrow", which represents weights of virtual objects without using conventional complicated haptic interfaces, is extended. The method recognizes hand gestures and motions of a user for grasping and lifting virtual objects. The Force Arrow indicates the current lifting speed and force. The extended method, called "Force Arrow 2", utilizes a visual effect by changing shapes of the virtual objects according to their virtual weight. The user is guided to increase or decrease speed and force during the lifting process with the visual effect. As a result, the user can perform the lifting process with the required speed and force (using "Force Arrow") and the visual effect (caused by presenting the objects in different sizes). With the proposed pseudo-haptic weight perception, a user can perceive weights of the virtual objects with simplified interfaces and visual effect in an immersive VR environment.