Treffer: Making Things Move.

In the real world, objects move in a variety of different ways, depending on what they are doing, and a game must approximate those motions to create a convincing virtual representation. A few games can get away with unrealistic motion—Pac-Man, for example, moves in a straight line with a constant speed and can change direction in an instant, but if you applied that kind of motion to a car in a driving game it would destroy the illusion. After all, in a driving game you would expect the car to take some time to reach full speed and it definitely shouldn't be able to turn 180 degrees in an instant! [ABSTRACT FROM AUTHOR]