Real-time collision detection in 3D cyber space by using the Z-buffer

We proposed a new algorithm, named Cyber Radar, for Real-time collision detection of geometric models in a 3D Cyber Space. To obtain the distance information, it renders the orthographic projection from the sensor object to the target area except the sensor object. If some object exists in the orthographic projection, Z-value of corresponding pixels in the Z-buffer would be less than the maximum. Then, it renders only the sensor object in the reverse direction, from the target area to the sensor object. By using those two sets of Z-values, each distance between the sensor object and other objects is calculated pixel by pixel. A case study of the Collision Detection between moving objects was already proposed [11]. This paper describes the case of object rotation. Especially when the axis of the rotation goes through the sensor object, the collision could happen in two sides of the axis. We propose the additional method of Cyber Radar for this case. Two Cyber Radars are mounted on a sensor object. The direction of them are orthogonal to the rotation axis and reverse each other.