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-to-point (steeplechase) Point-to-point (steeplechase) A point-to-point is a form of horseracing over fences for hunting horses and amateur riders. In Ireland, where the sport is open to licensed - i.e. professional - trainers, many of the horses will appear in these races before they compete in National Hunt races. Consequently, the Irish point-to-point is more used as a nursery for future young stars: a horse that wins its debut point-to-point in Ireland will often sell for a lot of money. Whilst professional trainers are specifically excluded from running horses in point-to-points in Great Britain (other than their own personal horses), the days