Layered manufacture of multi-level of detail models

For layered manufacturing, a 3D CAD model has to be converted from a solid representation to a 2D layered cross-section. The process usually involves face triangulation or meshing of a sculptured object and then extraction of layers from the meshed models. In current systems, the resulting model suffers from topological problems such as degenerate facets, undesired holes or flipped normals, resulting in incomplete cross-sections that cannot be manufactured as layers. Therefore, time consuming processes for facet repair were added to these CAD systems. This paper proposes a new method for extracting the layers and overcoming the topological problems. In this method, a mesh is reconstructed from the 3D model and represented in multi-level hierarchical structure. The proposed method utilizes the hierarchical model by extracting the layers in real time based on the incremental marching cube algorithm. Moreover, during construction, the method checks the topology and creates a valid cross-section that can be manufactured as layers. The method is applied to multi-level models so that a layered part can be constructed at any desired Level Of Detail (LOD), with rough or fine layers according to the application requirements. Several examples for layered manufacturing of multi-level models will be demonstrated.