Vanishing Point

Any parallel lines not parallel to the projection plane, converge at a vanishing point. If a set of lines are parallel to one of the three principle axes, the vanishing point is called an axis vanishing point. OR Parallel lines in the 3D model which are not parallel to the projection plane, converge to a vanishing point There are at most 3 such points, corresponding to the number of axes cut by the projection plane. For example if if z projection plane cuts the z axis: normal to it, so only z has a principle vanishing point, as x and y are parallel and have none -Horizon – observer’s eye level -Ground Line – plane on which object rests -Vanishing point – position on horizon where depth projectors converge -Projection plane – plane upon which object is projected

We can categorize perspective projections by the number of principle vanishing points, and the number of axes the projection plane cuts. Classes of Perspective Projection One-Point Perspective Two-Point Perspective Three-Point Perspective

View from above One-Point Perspective One principal axis cuts projection plane à one principal vanishing point Projection plane parallel to one principal plane

Two-Point Perspective Two principal axes cut projection plane à two principal vanishing points Projection plane parallel to one principal axis

Three-Point Perspective Three principal axes cut projection plane à three principal vanishing points

One point projection

Two point projection

Three point perspective projection