Based on the shadow-casting correlation of geometrical optics, a new correlation scheme for performing matrix-vector multiplication is proposed. The configuration can be simply regarded as an incoherent multichannel shadow-casting correlator. It is interest that it is capable fully parallel input and output, and its structure can be varied according to the demand. The general configuration form and the physical limitation of the scheme proposed here are discussed. Experiments are given, and show the method is very simply.