transPAF: Rendering Omnidirectional Impact Feedback with Dynamic Point of Application of Force All Round a Controller

Impact force is common haptic feedback on virtual reality (VR) controllers, such as hitting objects with weapons or rackets. It applies to different points of application of force (PAFs) and directions in varied scenarios. For example, using weapons with different shapes, e.g., a sword and a pickaxe, using a weapon in different ways, e.g., stabbing and slashing with a sword, or a ball flying and hitting a racket in different directions cause different PAFs and/or force directions. Therefore, to achieve realistic VR experiences, rendering dynamic PAF and force direction is essential. Although previous works have proposed the concept of dynamic PAF, the PAF is only in a limited space and without dynamic force direction. Therefore, we propose a controller, transPAF, to render omnidirectional impact feedback with dynamic PAF all round the controller for versatile VR scenarios. transPAF consists of a controller, a semicircular track, a linear track, and an impactor, which are all rotatable. The impactor can move to any position in a sphere, which means the whole 3D space all round the controller, and rotate in any direction. Therefore, dynamic PAF and force direction are achieved and independent to each other. We conducted a just-noticeable difference (JND) study to understand users’ distinguishability in position and direction, separately. A VR experience study was further performed to verify that feedback from transPAF with dynamic PAF and force direction enhances the VR experiences and demonstrate some applications for transPAF.