Abstract: A 3D positioning system and method, adapted for object tracking and positioning of virtual reality is provided. The method comprises: tracking a characteristic of at least a light-emitting component at a controller; calculating relative displacement information between each of the controller and a headset display device according to the characteristic; detecting first displacement information of the headset display device and second displacement information of each of the controller; transmitting the relative displacement information, the first displacement information, and the second displacement information to the host; and adjusting a corresponding virtual image of the virtual reality according to the relative displacement information, the first displacement information, and the second displacement information and transmitting the adjusted virtual image to the headset display device to display via the host.

Abstract: A shell device includes a protecting frame and a decorative plate. The protecting frame is removably mounted on an electronic device casing, and includes a loop-shaped plate portion for abutment with a back side of the electronic device casing, a frame opening defined by the loop-shaped plate portion, a loop-shaped surrounding wall extending transversely from the loop-shaped plate portion, and an abutting rib formed on an end of the loop-shaped surrounding wall opposite to the loop-shaped plate portion for tight abutment with an end of a lateral side of the electronic device casing proximate to a front side of the electronic device casing. The decorative plate is disposed within the loop-shaped surrounding wall, is exposed partially from the frame opening, and is covered partially by the loop-shaped plate portion.