A modular angular/curvature illumination assembly includes a plurality of channel units each of which has two opposite side walls gradually shaped by a step-by-step rolling process, during which a metal plate is moved through a series of roller die sets for rolling treatment. The die sets apply varying amount of pressure on the plate. A light unit is mounted on one of the channel units. A plurality of coupling units interconnect the channel units in such a manner that the side walls of any adjacent pair of the channel units are coupled together by means of one of the coupling units.