University of Waterloo, Waterloo, Ontario: 16mm.
"This film introduces orthographic projection by gradual transition from pictorial view to orthographic views. An orthographic view consists of at least two views of a point in order to show its 3-dimensional coordinates. The point is enclosed by a vertical plane, a horizontal plane, and a profile plane. The resulting box is rotated to show its relationship to the point. Perpendicular lines drawn from the point to each plane show the x, y, z coordinates. All resulting images are perpendicular to the edges of the box, and form a closed loop. By opening the box to form a flat surface, one can represent the 3-dimensional coordinates on paper, a 2-dimensional surface."