RAY TRACING MIRAGES

Ray tracing has been used extensively to produce realistic images. Traditional algorithms simulate various optical phenomena, including reflections, refractions, and shadows. With all of these the direction of the ray changes only when it intersects an object. Atmospheric variations, however, can cause light rays to bend, thereby changing their direction at any time. Mirages are just one possible visual effect of these bent rays. We generate mirages by sending rays through an object with multiple air layers having different refractive indices. As a ray enters this virtual object, it strikes several air layers and causes repeated bending of the ray, which results in the mirage effect. © 1990 IEEE