Perspective Using Curved Projection Rays and its Computer Application

The author describes a novel way for generating line drawings of 3-dimensional objects and describes a computer program that he used in plotting such drawings. Instead of being confined by the rules of linear perspective, which governs retinal and photographic images, he employs a more general mathematical model that provides a family of perspectives. Each member of the family is designated individually by a numerical value (between 0 and 1) for its index i. The lowest value, i=0, leads to the linear equation that applies to linear perspective, application of the highest value, i=1, results in axonometric projection. Sometimes linear perspective leads to a drawing or to a photographic image that seems grossly distorted in comparison with what one perceives in looking at an object. The author's method, employed with fractional values for i and with the same viewpoint, may be used to produce more acceptable drawing