Layout Optimization And Generation Of Digital Surface Bas-relief

Digital sculpture is an industrial artwork which integrates art and computer assist technique.With the development of intelligence artificial,virtual reality,and 3D print technology,digital sculpture generation has been become one of the most heated research fields.However,there are some problems that exist in the design and editing research of digital sculpture artworks,such as automatic best view selection,layout design,and complicated product process,etc.This paper carries out three research methods to solve these problems and improve the aesthetic value of surface bas-relief.The main research contents and conclusions of this paper are as followed:(1)The best view selection based on visual saliencyThe previous best view selection methods need convert 3D models to 2D image with depth information at first,and then compute the visual salience,which have complex processes.This paper presents a best selection method to calculate the visual salience,which can process 3D mesh models directly.There are three steps in this method: firstly,this method constructs the view point sphere of source 3D models,and take the every line between the vertexes of this sphere and center as the projection direction to compute the view attributes;secondly,this method applies visual salience model to measure the score of each view;finally,this method adopts the particle swarm algorithm(PSO)to improve the efficiency of this method.This paper uses several models to verify this method.The comparison result and user survey approve the efficiency and validity of this method.(2)The research on surface relief layoutThis paper presents two surface relief layout approaches:(1)The surface relief layout design based on symmetry rule.This method is based on the basic photograph composition rules,which can arrange single relief model automatically.(2)The surface relief layout design based on simulating annealing algorithm.This method builds the framework of this method by referencing 3D indoor design method.Given photographic composition rules and the previous research,this method extracts 7 evaluation indicators and constraint conditions,such as the curvature of the relief,separation distance,etc.Furthermore,this method constructs goodness function for each evaluation indicator.Then,this method regards the problem of forming the surface relief layout as a combinatorial optimization problem and solves the problem by constructing the cost function.This cost function assembles these evaluation indicators based on a weighted averaged model,which can reduce the calculation and increase the convergence rate.With the decline of cost function,the layout of relief approaches to reasonable.Finally,this paper experiments this method by various 3D mesh models.In addition,this paper analyses the efficiency and effect of method according to the experiment results and carries out user survey to verify this method.(3)Surface bas-relief editing algorithmBased on the researches of best view selection and surface relief model layout,this paper presents a surface bas-relief editing algorithm.This method applies the spatial weight matrix and Laplacian matrix to enhance the detail information,and then uses the nonlinear compression function to compress the model to generate bas-relief.Finally,this method adopts a surface parameterization based approach to attach the model to the target object.The experimental results indicate that the proposed approach can effectively process surface bas-relief with distinct details and clear outlines.Furthermore,by directly manipulating the mesh triangles,this approach can ensure the mesh topology of relief models to remain unchanged and attach to various surfaces.