Horizon science of graphical perspective. Assuming the picture plane stands vertical to ground, and "P" is the perpendicular projection of the eye point "O" on the picture plane, the horizon is defined as the horizontal line through "P". The point "P" is the vanishing point of lines perpendicular to the picture. If "S" is another point on the horizon, then it is the vanishing point for all lines parallel to "OS". But Brook Taylor (1719) indicated that the horizon plane determined by "O" and the horizon was like any other plane: The peculiar geometry of perspective where parallel lines converge in
Point plotting |"x"| from the origin and along the positive direction if "x"≥0, and the other direction otherwise. In the same way one picks the point on the "y" axis corresponding to the number "y". The line parallel to the "y" axis going through the first point and the line parallel to the "x" axis going through the second point will intersect at precisely one point, which will be called the point with coordinates ("x", "y"). Point plotting Point plotting is an elementary mathematical skill required in analytic geometry. Invented by René Descartes and originally used to locate positions on military maps,