Daoling is a typical mountain village. Folk houses are arranged in a fan-shaped trapezoidal pattern around the water mouth, surrounded by thousands of ancient trees and ten thousand mu terraced fields. Flowers and seas in four seasons display a stunning "earth art".
This paper deals mainly with the operationof a trapezoidal controller and the exposure procedure of a trapezoidal pattern, by the way the exposure of a rectangular pattern is described first.
Exposure of a trapezoidal pattern is obtainedby resolving it into a series of element rectangles, and then exposuring them inorder so as to make up a trapezoid.
