UNC-CH Computer Science Educational Outreach 

  Defining Virtual Reality

If you work with computers, you probably use a mouse and keyboard to input information. When you move the mouse or type on the keyboard, you are telling the computer something you want it to do. In this way you are interacting with the computer.

Virtual Reality is a major breakthrough in the way humans work with computers. It allows us to move beyond computer keyboards and flat monitor displays to interact with a three-dimensional computer-generated world. Though the exact definition of virtual reality is disputed by many researchers, most would agree that virtual reality systems successfully convince the viewer that the virtual world is believable. Using methods of display, tracking, and rendering (which we'll talk about later), VR allows the user to become immersed and to interact in a virtual world.

Imagine putting on a head-mounted computer display (or HMD for short) to see another world.  Imagine using a computer-controlled glove on your hand to perform tasks in this virtual environment. With the HMD on, you are visually immersed in this simulated environment where you can see depth, shadows, colors, and textures.  However, you can’t see any of the real world---just the computer-generated environment.  Immersion is one of two important distinguishing characteristics of VR.

Now imagine that the computer-controlled glove on your hand is actually a baseball glove in the virtual world. When you turn your head to the right and left, your view of the world changes too! Reach out and catch the ball. You see the glove extend and then close. You could catch a baseball and feel it hit your glove; you can hear the ball smack against your glove. These actions in the computer world correspond to your actions because your gestures are being transmitted to the computer by a tracking device on the helmet you wear and the device you hold---they are communicating with the computer like a mouse and keyboard do.

When you enter the virtual environment, you’re entering an interactive environment.  Interactivity is the second distinguishing characteristic of VR. Interactivity with the environment means that your actions will generate changes within the virtual environment; these changes must be registered and updated by the computer so you can see them displayed in the HMD. Best of all, the virtual environment you enter is not limited or governed by natural laws; instead, the only limitation is your imagination.

    Back to Introduction to Virtual Reality