A multi-axis adaptive slicing algorithm which can generate optimal slices to achieve deposition without support structures for multi-axis layered manufacturing is presented in this paper. Different from current adaptive slicing, this technique varies not only in layer thickness but also in slicing direction. Aware of potential problems of previous research on slicing, the work in this paper studied an innovative geometry reasoning and analysis tool-centroidal axis. Similar to medial axis, it contains geometry and topological information but is much computationally cheaper. Using a centroidal axis as a guide, the multi-axis slicing procedure is able to generate a 3-D layer or change slicing direction as needed automatically to build the part with better surface quality. This paper presents various examples to demonstrate the feasibility and advantages of centroidal axis and its usage in the multi-axis slicing proces
