Virtual reality systems are computer-generated environments where an user experiences sensations perceived by the human senses. These systems are based primarily on providing video and audio signals, and offer the opportunity to interact directly with the created scene with the help of touch or other form of manipulation using hands. Vision systems for virtual reality environments consist most frequently of head-mounted goggles, which are equipped with two liquid crystal displays placed opposite the eyes in a way that enables stereoscopic vision. The image displayed in the helmet is rendered independently for the left and right eye, and then combined into the stereopair. More and more solutions appear on the market, and the most popular include: HTC Vive, Oculus Rift CV1, Playstation VR (dedicated for Sony Playstation 4), Google Cardboard (dedicated for Android mobile devices).
The concept of using an eye tracker for steering in the virtual reality environment assumes the usage of the eye focus point to interact with objects of the virtual scene. An overview of the system built upon this concept is presented in Fig. 1 and the process of interaction consists of the following steps: – mapping the direction of the user’s eye focus on the screen coordinates, – generating a primary ray (raycasting using the sphere) from the coordinates of the user’s eye focus direction, – intersection analysis with scene objects, – indication of the object pointed by the sight, – handling the event associated with the object, – rendering a stereopair for virtual reality goggles.
