Figure 5.

1session sequence. A subject wearing head-mounted display (HMD) is instructed to perform sequential tasks of relocating virtual “eggs” of random size appearing at a random location in a predetermined “appearance range” on the right side in the VR space to a “goal area” in the center region (Figure 4). During this experiment, reaching, grasping, moving and releasing target eggs are performed continuously and repeatedly for about 1 min for each one session of scene-A (without visual haptics) and scene-B (with visual haptics). These subjects are instructed to grasp the egg gently not to break and to move many eggs to the goal as possible as they can. In this experiment, the egg is not modeled to break when the excessive force is added.