Rotoscoping, as a technique, involves tracing over film output to get an animated version of the frame. It is that simple, really. Animation purists decry Rotoscoping as an animation technique but it does have its uses. Rotoscoping has often been used as a tool for special effects in live action movies. By tracing an object, a silhouette (called a matte) can be
created that can be used to create an empty space in a background scene. This allows the object to be placed in the scene. However, this technique has been largely superseded by bluescreen techniques. Rotoscoping has also been used to allow a special visual effect (such as a glow, for example) to be guided by the matte or rotoscoped line. One classic use of traditional rotoscoping was in the original three Star Wars films, where it was used to create the glowing lightsaber effect, by creating a matte based on sticks held by the actors. The term "rotoscoping" (typically abbreviated as "roto") is now generally used for the corresponding all-digital process of tracing outlines over digital film images to produce digital mattes. This technique is still in wide use for special cases where techniques such as bluescreen will not pull an accurate enough matte. Rotoscoping in the digital domain is often aided by motion tracking and onion-skinning software. Rotoscoping is often used in the preparation of garbage mattes for other matte-pulling processes.

It is the "interpolated" part of "interpolated rotoscoping" that intrigues us more, though. In the mathematical subfield of numerical analysis, interpolation is a method of constructing new data points from a discrete set of known data points. In engineering and science one often has a number of data points, as obtained by sampling or some experiment, and tries to construct a function which closely fits those data points. This is called curve fitting. Interpolation is a specific case of curve fitting, in which the function must go exactly through the data points. In animation interpolation is the technique in which a frame can be drawn, then a future frame can be drawn, and the intermediate frames are automatically generated. It is a simple form of "automatic inbetweening." Interpolated lines and shapes have a very smooth, fluid motion that is extremely difficult to achieve by hand-drawing each line.

"A Scanner Darkly" utilises this technique well - creating a stylised world with a heightened sense of disconnect from reality - causing the film to fall into the Uncanny Valley of the viewer - a topic we have discussed in the past. Rotoscoping is not a technique for everyone. Linklater uses it to good effect for a film that is meant to daze and confuse, beffudle and disorient. Rotoscoping, and its associated liberties, add to the ambience of the movie and we look forward to seeing rotoscoping applies as well as it was in "A Scanner Darkly".

Rotoscoping, as a technique, involves tracing over film output to get an animated version of the frame. It is that simple, really. Animation purists decry Rotoscoping as an animation technique but it does have its uses. Rotoscoping has often been used as a tool for special effects in live action movies. By tracing an object, a silhouette (called a matte) can be
created that can be used to create an empty space in a background scene. This allows the object to be placed in the scene. However, this technique has been largely superseded by bluescreen techniques. Rotoscoping has also been used to allow a special visual effect (such as a glow, for example) to be guided by the matte or rotoscoped line. One classic use of traditional rotoscoping was in the original three Star Wars films, where it was used to create the glowing lightsaber effect, by creating a matte based on sticks held by the actors. The term "rotoscoping" (typically abbreviated as "roto") is now generally used for the corresponding all-digital process of tracing outlines over digital film images to produce digital mattes. This technique is still in wide use for special cases where techniques such as bluescreen will not pull an accurate enough matte. Rotoscoping in the digital domain is often aided by motion tracking and onion-skinning software. Rotoscoping is often used in the preparation of garbage mattes for other matte-pulling processes.

It is the "interpolated" part of "interpolated rotoscoping" that intrigues us more, though. In the mathematical subfield of numerical analysis, interpolation is a method of constructing new data points from a discrete set of known data points. In engineering and science one often has a number of data points, as obtained by sampling or some experiment, and tries to construct a function which closely fits those data points. This is called curve fitting. Interpolation is a specific case of curve fitting, in which the function must go exactly through the data points. In animation interpolation is the technique in which a frame can be drawn, then a future frame can be drawn, and the intermediate frames are automatically generated. It is a simple form of "automatic inbetweening." Interpolated lines and shapes have a very smooth, fluid motion that is extremely difficult to achieve by hand-drawing each line.

"A Scanner Darkly" utilises this technique well - creating a stylised world with a heightened sense of disconnect from reality - causing the film to fall into the Uncanny Valley of the viewer - a topic we have discussed in the past. Rotoscoping is not a technique for everyone. Linklater uses it to good effect for a film that is meant to daze and confuse, beffudle and disorient. Rotoscoping, and its associated liberties, add to the ambience of the movie and we look forward to seeing rotoscoping applies as well as it was in "A Scanner Darkly".