P5. Line geometry During the nineteenth century, line geometry was studied intensively. In terms of the bijection given above, this is a description of the intrinsic geometry of the Klein quadric. Ray tracing Line geometry is extensively used in ray tracing application where the geometry and intersections of rays need to be calculated in 3D. An implementation is described in Introduction to Plücker Coordinates written for the Ray Tracing forum by Thouis Jones. See also Flat projective plane Plücker matrix References From the German: Grundzüge der Mathematik, Band II: Geometrie. Vandenhoeck & Ruprecht. Projective geometry Multilinear algebra Geometric algebra Coordinate systems