 Many studios established in-house "special effects" departments, which were responsible for nearly all optical and mechanical aspects of motion-picture trickery.Also, the challenge of simulating spectacle in motion encouraged the development of the use of miniatures.Animation, creating the illusion of motion, was accomplished with drawings (most notably by Winsor McCay in "Gertie the Dinosaur") and with three-dimensional models (most notably by Willis O'Brien in "The Lost World" and "King Kong").