The LOOK method in VPGL Language searches for the 3D geometies for specified direction.
LOOK takes 2 inputs. Input 0 must be a 3d Geometry, and input 1 must be a 3-elemets array contains 3 numbers formed [ px py pz ].
LOOK searches for objects crossed the line form the center of input 0 to the point (px, py, pz).
LOOK emits the array which contains all crossed 3D geometries to output 0. This may be empty array.