The 2 equations obtained above indicate that the motion field of a pure translation is radial . Motion Parallax Motion parallax occurs when 2 3D points project to the same 2D location. Let P , and P' be 2 different 3D points with projections p , and p' . Notice that the relative motion field does not depend on the rotational component of motion. Other factors being equal, dv x and dv y increase with the separation in depth between P and P' .
T are the coordinates of the vanishing point.