what is prespective art.?

Linear perspective is a mathematical system for projecting the three-dimensional world onto a two-dimensional surface, such as paper or canvas. In brief, this type of perspective begins with a horizon line,which defines the farthest distance of the background and a central vanishing point. To this vanishing point, orthogonals may be drawn from the bottom of the picture plane, which defines the foreground of the space. The orthogonals, vanishing point, and horizon line establish the space in which the artist may arrange figures, objects, or architecture such that they appear to exist in three dimensions. Once these basic elements have been set in place, the artist may add further elements to create a more complicated, yet more realistic, space. For example, to represent a square-tiled floor, the artist chooses another point on the horizon line, called the distance point, and draws a line through the orthogonals to a point at the bottom of the picture plane. The points at which this line bisects the orthogonals establish the points at which horizontal lines, called transversals, may be placed. These lines represent the perspectively correct regression of the square tiles into space (see diagram). These elements of linear perspective link the science of three-dimensional geometry with the art of illusionis.

In the 13th and 14th centuries, before linear perspective was discovered, artists occasionally employed something called reverse perspective, in which parallel lines splay rather than converge as they approach the horizon line. One of the rules set forth in an early artists' manual is that elements above the eye of the viewer tend downward (like roofs), while elements below the viewer’s eye tend upward (like tables). While arbitrary tilting of lines upward and downward can create unusual effects, this is generally considered to be a significant step in the progression toward the rational application of linear perspective.

It was not until the Renaissance that artists began to refine this science. Linear perspective soon emerged as the tool for artists to capture the world around them in a remarkably illusionistic manner (this was the same time that cartographers were mapping the surface of the earth using a similar system of mathematical projection). Masaccio's (1401–28) Trinity (1427–28), considered to be the first accurately perspectival painting in the Western tradition, introduced the relationship between linear perspective and subject matter in art. The painting is divided into three levels: the figure of God stands on a tomb above and behind Christ crucified on the cross; the Virgin Mary and St. John the Baptist stand at the base of the cross; and two donors, who commissioned the painting, kneel on either side of the cross at the lowest level. The figures are harmoniously organized underneath a barrel-vaulted ceiling. The figure of Christ and the barrel vault are rendered as if seen from below. The figures of Mary and John are rendered again as if from below, but just lower than Christ. The two donors, given the lowest vanishing point, are rendered as if seen, directly in front of the viewer’s eye. In this way, the painting provides the illusion that the viewer is looking at sculptural forms that exist in three dimensions and rise vertically in space. Yet the accurate, illusionistic representation of space in this work has no obvious theological meaning. It has much more to do with the artist exhibiting his skill—injecting his own thoughts into this religious image.