A 3D distance sensor projects a plurality of points of light onto a target. A 2D camera having a fixed position relative to the 3D distance sensor acquires a first image of the points on the target. A light receiving system of the 3D distance sensor acquires a second image of the points on the target. A set of 2D coordinates of a first point is associated with a distance coordinate of the first point to form a single set of coordinates for the first point. The set of 2D coordinates is obtained from the first image, and the distance coordinate is obtained from the second image. A relational expression is derived from the single set of coordinates and describes a relationship between a distance of the light receiving system to the target and a position of the first point on an image sensor of the 2D camera.