"INVISIBLE -The Shadow Chaser-" is VR game that players capture the invisible monsters
(called goblins) by the help of their shadows and footsteps.
| ■Concept | |
This project aims the representation of feeling that a user can feel the existence of unseen objects through their indirect information. In this project, direct information of virtual objects is defined as description of their appearances such as a stereoscopic image in the scene. Indirect information is defined as incidental information which they may cause in the environment around them, for example, shadows, sounds, and weights etc. Under this concept, we produce the game of "INVISIBLE". |
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 Goblins |
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| ■Outline | |
In this game, goblins are invisible and moving in the cubic game space and only their shadows can be seen on the floor. And their footsteps can be heard from speakers. Players have to estimate their position from the shadows and sounds, catch them. When players succeed in capturing goblins, a player may experience a sense of invisible goblins' existence by vacuuming resistance and increase in weight of vacuum tank on his back. | |
 Outline(Click to enlarge) |
 Play image(Click to enlarge) |
| ■System | |
This work consists of the following systems.
-the projector for showing the shadow of goblins and sensors. -The switch for instruction of capture, The weight presentation equipment which feeds back the feeling of capture, etc. | |
 System(Click to enlarge) |
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・ The device for shadow projection System to obtain the 3D information (position and orientation) of the projector uses Infrared LEDs and a camera with IR transmission filter. Each horizon positions of devices are obtained by illuminations of infrared LEDs. Information of 3 angles (pitch, yaw and roll) is obtained from 3DOF(degrees of freedom) tracker. Height of the projector is calculated by these horizon distance and roll angle. | |
 The device for shadow projection (Click to enlarge) | |
 3D position acquisition diagram (Click to enlarge) | |
For shadow projection, we use the projector. At the time, we make virtual 3D space same standard as a real space, and 3D position and orientation of the projector in the real space are set to camera in the virtual space. Now, the color of 3D material in the virtual 3D space is black, and reflectance is zero. Rendered image is masked so as to make an actual spotlight shape. That makes shadows of goblins. Dynamic image is projected by the projector, and goblin's shadow is shown properly in the real space. | |
 The projection principle of a shadow (Click to enlarge) | |
・ The device for capture The device for capture consists from the vacuum-like pipe that the player has in the hand and the backpack for weight. | |
 The device for capture (Click to enlarge) | |
When the switch in the pipe is pushed, at first, the signal showing that a switch is pushed is sent to PC. Second, in PC, it is judged that whether the player can capture goblins from the position information of the nozzle point and goblin's position, and it is possible, the start signal will be transmitted to the device for capture. Small vibration motors are attached in the pipe. When the start signal is received, they vibrate sequentially from the nozzle toward the handle. That makes sense of capturing. When the goblin is captured, water is moved from the water storage tank on ground to the tank for weight presentation with the pump. Air in the tank for weight presentation is pushed out to the storage tank for through a special tube. Therefore, the part (tank for the weight presentation and the joint) that has and moves can be sealed up completely. At the same time, a large vibrating motor equipped in the backpack is used to present a sense that captured goblin is struggling and not to be perceived the drive of the pump to the player. | |
 Weight presentation equipment (Click to enlarge) | |