Research And Applications On Segmentation And Splicing On Three-dimensional Based On Additive Manufacturing

With the rapid development of Additive Manufacturing,the popularity rate of Additive Manufacturing equipments is increasingly.The model file for the equipment is STL(Stereo Lithography)file,which is exported from CAD(Computer Aided Design)system.At present,the main approach for modifying STL files is to fallback to the CAD system but could not modify the model directly in STL format.But it is a higher professional way so that normal customers have to giving up when they met a unsuitable model,or spending a lot of time to conduct a secondary machining.This condition makes a method which can modify the STL file directly will improve user experience and promote the development of additive manufacturing industry.So,it will make a dfference by proposing a method which can modify the model directly in STL format.The main contents and innovations of this paper are as follows:(1)A method in cutting STL file which is range-controllable has been proposed.A topological structure which proposed by this paper has been used by this method,and firstly,this paper solved the cutting by a plane in any angle according to synchronous rotation of model and plane.Then a method about point pick-up in three-dimension model based on OpenGL has been come up,which can pick-up all the point in the surface of model whether in any angle.Finally,based on the two method above,thus the cutting range can be determined and binding to the model and achieving the range-controllable cutting.This method makes a great convenience in partial modification.In addition,the problem of the model is larger than the work surface could be deal by this method.(2)A method in combine STL file which is based on boundary recognition has been proposed.The method distinguishes the interference section through the original position of models.In order to reduce the obstruct of irrelevant part,the topological structure is splited according to the section.Aimed at model stitching,the method recognizes the junction boundary and normal vector,thus distinguishes planes and then conducts a ablation and reconstruction.Aimed at model fusion,the method gets the fusion site profile through the topological structure,and make a judgement on model within the different boundary about whether delete or save.This method makes a amplification advantage on once forming of additive manufacturing.It also saves time when a lot of piecemeal medol need to be manufacture.Based on the innovations above,an interactive platform based on OpenGL is designed.This platform support point pick-up and physical transformation on model.Experimental results show that the method in cutting STL file which is range-controllable can cut off the designated site.When enlarge the range,it can convert to plane cutting in any angle.In addition,the method in combine STL file which is based on boundary recognition which proposed by this paper can distinguish whether the models are stitching or fusion and combine models according to requirements.In summary,the innovations can be used to modify the STL file directly effectively.Thus improved compatibility between models and equipments and promoted the development of additive manufacturing industry.