3D computer graphics 3D computer graphics, or “3D graphics,” sometimes called CGI, 3D-CGI or three-dimensional computer graphics are graphics that use a three-dimensional representation of geometric data (often Cartesian) that is stored in the computer for th ...

, a lathed object is a 3D model whose vertex geometry is produced by rotating the points of a spline or other point set around a fixed axis. The lathing may be partial; the amount of rotation is not necessarily a full 360 degrees. The point set providing the initial source data can be thought of as a cross section through the object along a plane containing its axis of radial symmetry. The reason the lathe has this name is because it creates symmetrical objects around a rotational axis, just like a real lathe would. Lathes are very similar to surfaces of revolution. However, lathes are constructed by rotating a curve defined by a set of points instead of a

function Function or functionality may refer to: Computing * Function key, a type of key on computer keyboards * Function model, a structured representation of processes in a system * Function object or functor or functionoid, a concept of object-oriente ...

. Note that this means that lathes can be constructed by rotating closed curves or curves that double back on themselves (such as the aforementioned torus), whereas a surface of revolution could not because such curves cannot be described by functions.

See also