<channel 4 commissioned me to write a booklet to accompany the film, designed to provide a more detailed context for the material than could be covered in the documentary.../>
The techniques of animated film-making and their potential

“An animated film presents only an illusion of movement. Due to a function of the human eye and brain, known as persistence of vision, enabling an image exposed to the retina to be retained for a fraction of a second, a sequence of related separate still images projected in quick enough succession will appear as a single moving image. Film is projected at 24 frames per second, meaning that for every second 24 frames must be shot.

In the language of the animated film, movement can be described under three general headings: cycle, metamorphosis and growth. A cycle is a recurrent movement which returns to its beginning in a regular rhythm. The basic cycle is the so-called 'walk cycle', in which a set of drawings of a character walking may be recycled ad infinitum over a moving background. It is used frequently as a time-saving device in many films, although it should be in fact applied sparingly, since it becomes rather obvious after a short time. There are very few cycles incorporated into Taking a Line for a Walk, since their presence would have contradicted the fundamental principle of constant flux within the forms.

 

The other two interrelated types of movement, metamorphosis and growth, have been used much more consistently in the film. Metamorphosis is a process of transformation from one form into another, and growth is a releasing of the potential within an individual form. Apart from these basic types of movement and their combinations, a more prosaic shift in position or size completes the range.

Mere movement itself conveys very little. The art of animation lies in the ability to time the movement, which is where the technique of varying the speed or holding the movement still is temporarily applied, in order to give the sequence pace and dynamism. Timing is one of the most crucial principles in all of the performing arts. It is fundamental to theatre, dance, music, mime. It is an essential ingredient of certain forms of humour. The essence of timing is bound up in the concept of the interval. Absolute, variable but immutable intervals between incidents in time and/or space create an internal tension within the structure of a piece. The lengths of the intervals are determined by the duration, size and quality of the events. In the visual arts the element of time is converted into the dimensions of spatial relations within the picture plane...”

recommended reading:

Paul Klee Notebooks Volume 1 - The Thinking Eye
Paul Klee On Modern Art
Paul Klee Pedagogical Sketchbook