This study aims to build a triangular-mesh model directly from scanned 3D data points, which then generate the stereolithography (STL) file, thus avoiding the troublesome task of producing a CAD model. Accuracy of the triangular-mesh model is achieved because the pitch between data points is generally very small. In addition, the paper proposes a multi-nozzle path algorithm to increase both spraying efficiency and part accuracy. The processing procedure includes: (1) Establishing the triangular-mesh model from scanned data points, which are retrieved by means of contact-or non-contact type measuring machines as well as developing the algorithm to add the radius of the probe automatically.(2) Equally slicing the triangular-mesh solid model and plan spraying paths. (3) Determining the amount and diameter of nozzles appropriate for each slice to generate multi-nozzle spraying paths.