ABSTRACT
When a visual effects (VFX) element is added to the footage, it needs to be placed at the proper distance from the lens. This is a constant challenge, because the footage itself is two-dimensional and there is no way to separate objects within it based on their distance from the camera. In modern rotoscoping(roto) the artist articulates the contours of the subject with a line that is defined by numerous dots. Roto works well for subjects with hard, well-defined edges. It seems as if green screens are the symbol, the essence and the raison d'être of VFX rather than a mere tool for separation. But green screens are not a fashion, nor a style; they are simply a means to allow cleaner and faster separation of subjects. The green screen extraction process is far from being a push-button affair, and requires considerable work and a fair amount of expertise from the compositor.
