Along with the recent spread of 3D printing technology, researchers have developed various materials and equipment, now widely disseminated among individuals and industries. However, most of the current metal 3D printers generate the cutting paths using cutting software only, which doesn’t consider heat input of the plasma or laser. In the wire arc additive manufacturing (WAAM) system, a projection algorithm is created through the CATIA application programming interface. Different from the existing cutting algorithm, this algorithm converts a two-dimensional (2D) image into a three-dimensional (3D) structure by orthogonal projection and a voxel algorithm that expresses a 3D finite volume element. To fix the (x, y) coordinates and the z (Height) coordinate to be on the 2D plane, the projection algorithm models the 3D geometry orthogonal to the 2D plane. The bead modeling data and the step-over values generating the laminate shape were determined. The core of the voxel algorithm that models the free-shape lamination obtains the point location of the wire arc, considering the bead size and the distance between the layer spacing and the voxel center point (According to the processing conditions). Finally, the correct projection and voxel algorithms are selected using a lamination path-acquisition strategy.