A projection is a transformation in which the image figure is obtained from the original figure (plane or three-dimensional) by drawing from the point of the original figure straight lines, which are either parallel (parallel projection), or concurrent (central projection), and which intersect the image plane. The points of intersection of the straight lines (rays of projection) with the image plane are the image points, the totality of which yields the image figure. The figure is said to be projected onto the image plane. See also projective geometry.