Visual Effects . Rotoscoping Visual Effects Rotoscoping Roto, for short, is the painstaking process of generating mattes for plates that are to be composited. These black and white shapes are generated as pieces of digital footage that are either stored separately or in the alpha channel of a file format like Quicktime or sequences of pict files. Roto is a general term that covers many techniques. Mattes may be generated with digital paint or, in most professional tools , through the use of animatable splines.
Splines are paths drawn in one of two fashions.
Bezier splines are more common and will serve as a good introduction as they are found in many desktop tools that may not even involve video. These tools include, but are not limited to, Adobe Illustrator and Macromedia's Freehand. The other spline type is refered to as natural or B-splines. These are not very common outside of high end tools . The main difference between the two types of splining has to do with the way the shapes are drawn and later animated.