Linear perspective

Linear perspective is the art of representing three-dimensional constructions on a two-dimensional surface. It presupposes a fixed viewpoint and a desire to create an "objective" recording of one's visual experience - two conditions which have been the most dominant in the Western art of the past half-millennium.

3rd kind of vanishing points

If the lines have angles from the painting plate up or down, one would use the other kind vanishing points. Those vanishing points must located in the same vertical line with the focus. Looking at the object from above or below, the horizontal line with the focus and all other 2nd VPs would left the horizon up or down.

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Three-point perspective exists when the painting plate is viewing a "Cartesian scene" (a scene composed entirely of linear elements intersecting at right angles) and is not parallel to any of the scenes three axes. Elements that are parallel to each of the three axes will converge to three vanishing points respectively.

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