Realistic fog sim comes without high-tech rendering

Posted by Mark Raby

San Diego (CA) - Computer scientists at the University of California San Diego have created a new computer application to simulate fog without the usual lag of intense computations.

Wojciech Jarosz, the Ph.D. student who led the engineering project, discovered a computational short cut to make rendering of obscured lighting situations a more streamlined and efficient process.

The new algorithm can be used to create realistic simulations of an environment where "some material hanging the sky", like fog, interacts with the light.  It could also be used for lighting effects of smoke, fire, and full-on explosions.

Instead of the old method where programmers would need to define every single point in the line of vision, Jarosz and his team compute the lighting at a representative area of the entire group and then use that information to interpolate the lighting for the rest of the scene.

"If you want to compute all the lighting along a ray, our method saves time and computational energy," said Jarosz.

In addition to rendering still images more quickly with this method, it can be used for 3D environments with a moving camera, where existing lighting computations are re-used, lessening real-time lag that could occur with older rendering methods.

The quicker, easier, less taxing algorithm could be used in computer animated films, CG sequences in live action movies, or in a more open-ended environment of a video game.  Jarosz called the breakthrough important for graphical programmers, saying, "Being able to accurately and efficiently simulate these kinds of scenes is very useful."