Table Paint
Author(s): Alvy Ray Smith.
Misc: Published as Tutorial Notes at SIGGRAPH '80 and SIGGRAPH '81,
1979.
[BibTeX] 
Abstract:
Table look-up procedures are particularly useful at computer graphics installations because of the large chunks of cheap random access memory (framebuffers) which tend to be components of these facilities. We explain here how one additional framebuffer and one analog control device in addition to the tablet create a powerful and flexible extension to any typical framebuffer painting program. In particular, this readily available extra equipment gives the artist brushes which change size, shape, orientation, and/or color in realtime and smoothly. Examples are rotating brushes, animated brushes, airbrushes with changing spread and density, oriented brushes which track the direction of motion, and many more. That is, the artist is given a third dimension of stylus control which may be as graceful as the spatial two. He may define this new dimension from a menu of selections. The extra framebuffer is used as table memory. The extra device (e.g., joystick, trackball, pot, footpedal, microphone, strain guage, keyboard) is used as a controller for the added dimension. Realtime is obtained by using the output of the controller for table look-up.