Graphical projection Perspective projection is a linear projection where three dimensional objects are projected on a "picture plane". This has the effect that distant objects appear smaller than nearer objects. It also means that lines which are parallel in nature (that is, meet at the point at infinity) appear to intersect in the projected image, for example if railways are pictured with perspective projection, they appear to converge towards a single point, called vanishing point. Photographic lenses and the human eye work in the same way, therefore perspective projection looks most realistic. Perspective projection is usually categorized into "one-point", "two-point" and "three-point
Ideal point Ideal point In hyperbolic geometry, an ideal point, omega point or point at infinity is a well defined point outside the hyperbolic plane or space. Given a line "l" and a point "P" not on "l", right- and left-limiting parallels to "l" through "P" converge to "l" at "ideal points". Unlike the projective case, ideal points form a boundary, not a submanifold. So, these lines do not "intersect" at an ideal point and such points, although well defined, do not belong to the hyperbolic space itself. The ideal points together form the Cayley absolute or boundary of a hyperbolic geometry.