Vanishing point as the "direction point", as lines having the same directional vector, say "D", will have the same vanishing point. Mathematically, let be a point lying on the image plane, where is the focal length (of the camera associated with the image), and let be the unit vector associated with , where . If we consider a straight line in space with the unit vector and its vanishing point , the unit vector associated with is equal to , assuming both are assumed to point towards the image plane. When the image plane is parallel to two world-coordinate axes, lines parallel
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,