Wire arc additive manufacturing (WAAM) is a process included in the directed energy deposition (DED) category of additive manufacturing which involves building parts layer by layer using gas metal arc welding (GMAW), gas tungsten arc welding (GTAW), or plasma arc welding (PAW). Machining and heat treating often follow the WAAM deposition to achieve the desired geometric tolerances, surface finish, and properties. While many software applications exist for layer-by-layer additive manufacturing, few are designed specifically for robotic WAAM. The computer aided design (CAD) software, Rhino 7, and its built-in programming tool, Grasshopper, allow for parametric manipulation of primitives such as curves, points, and meshes in the virtual space, making development of custom slicing scripts possible. In combination with plug-ins such as KUKA|prc, slicing, path modification, and code generation can all be completed within the software. This paper demonstrates scripts developed in Rhino 7 for control of welding paths in robotic WAAM and describes how these scripts may be applicable to other manufacturing processes.