  This paper presents a new curved layer volume decomposition method for
multi-axis support-free printing of freeform solid parts. Given a solid model
to be printed that is represented as a tetrahedral mesh, we first establish a
geodesic distance field embedded on the mesh, whose value at any vertex is the
geodesic distance to the base of the model. Next, the model is naturally
decomposed into curved layers by interpolating a number of iso-geodesic
distance surfaces (IGDSs). These IGDSs morph from bottom-up in an intrinsic and
smooth way owing to the nature of geodesics, which will be used as the curved
printing layers that are friendly to multi-axis printing. In addition, to cater
to the collision-free requirement and to improve the printing efficiency, we
also propose a printing sequence optimization algorithm for determining the
printing order of the IGDSs, which helps reduce the air-move path length. Ample
experiments in both computer simulation and physical printing are performed,
and the experimental results confirm the advantages of our method.
