Sketch-based 3D Modeling Method On Mobile Device Based On Contour Recognition

The rapid development of 3D(Three-Dimensional)printing technology promotes the industri-alization of 3D printing.More and more people want to use 3D printing to create unique products that can hardly be mass-produced by traditional manufacturing methods.3D printing,i.e.additive manufacturing technology,driven by 3D data,requires computer to discrete and analyse hierarchy of the model first,and then stack material layer by layer to get the prototype finally.3D modeling methods,as the basis of 3D modeling,are thus facing new users and new opportunities.In order to enable amateur users to design and create their 3D model,this paper comes up with 3D modeling algorithms and interactive gestures for mobile terminals based on the characteristics of mobile devices.Some core functions used in the process of 3D modeling are intellectualized and displayed reasonably on the mobile devices.So that,users can still quickly grasp the modeling method without relevant background knowledge.First of all,this paper analyses the pros and cons of the 3D modeling applications using system analysis methods,and summarizes 3D modeling software requirements of the amateur users.Next,every design schema of the system is evaluated based on the requirements analysis,and finally,we get the 3D modeling system design which is a best fit for mobile device and amateur users.Afterwards this paper concretely fulfilled the system design from both algorithmic and in-teractive design aspects.In the aspect of 3D modeling algorithms,every algorithm involved in each modeling step is redesigned for amateur users,from sketch drawing to 3D model extrusion and editing.This paper combines the advantages of sketch-based modeling method with those of image-based modeling method,and raises an automated algorithm to optimize the user's sketch according to the background image,which is economical of time for detailed modification.The 3D model is inflated automatically based on the outline of the sketch,which reduces user work-load during modeling to a great extent.The two-dimensional contour line of a model is utilized to simplify the operation of editing the shape of 3D model.The algorithm automatically transforms the user's operation of 2D contour line into 3D mesh deformation,and reduces the user's difficulty in the deformation operation on mobile device.In the aspect of interactive design,two scenarios are designed to separate the modeling op-erations and 3D walkthrough operations,taking into account the characteristics of the mobile de-vices.Consequently,the user operations are more clearly and the possibility of wrong operations is reduced.Besides,multi-touch and double-hand operations are combined to enhance interactive experience while modeling and speed up modeling process.