We use the angle subtneded by an object. But a picture of a 3-D object subtending 15o may be observed at less than 1o or more than 36o and still look quite good. Touch may use some aspects of perspective, including what faces the vantage point, the angle made by large objects at the vantage point, and foreshortening. Indeed, vision and touch may share a common spatial sense. Some used obliques and lines getting thinner when sked to show the object's orientation.
Blind people succeed at using convergence to show objects receding and changing direction.
Drawins of tables can be made in different ways, depending on the system of perspective employed. Blind subjects assign ages to the systems appropriately and match drawins of different objects aptly. But she finds the child can draw the route's shape, if asked. Kerr finds blind act like sighted subjects on a mental spatial imagery task, but are a bit slower. This page was designed and is maintained by William Barek, CITD - Bladen Library.