Research And Implementation On Simplified Scheme Of Three-dimensional Model Based On OpenGL

Currently,large-scale data's visualization and real-time display have been widely used in many areas,such as virtual reality,video games and movies.Three-dimensional solid display technology has become a hot area of research.With the development of three-dimensional modeling and data acquisition and other related technologies,and in order to improve the effect of the analog display,three-dimensional model becomes more complex.The triangular mesh data for these models often contain hundreds of thousands or millions of facets,some models even reached millions.The features of this three-dimensional model is complex and larger amount of data.This makes the model becomes difficult to store,difficult to transport,difficult to draw,and it also create huge challenges for Human–Machine Interaction.So how to simplify the mesh model and retain the geometric features is very important.This thesis simplified start a meaningful exploration of Model Simplification,and study the characteristics of four basic model simplification algorithm s for geometric element decimation,vertex clustering method,sampling method and adaptive refinements.On this basis,this paper further studied the QEM edge collapse algorithm.The QEM edge collapse algorithm can't retain the minutiae of three-dimensional model when the model is highly simplified.In order to solve this defect,an edge collapse simplification algorithm based on normal and volume error is presented in this paper.The algorithm calculates the spatial location of the new vertex after edge collapse by the butterfly-shaped interpolating subdivision,and then computes the vertex normal and volume error of the simplified grid in edge collapse according to the spatial location of the new vertex and establishes a folding sequence,and at last carries out the operation of edge collapse of the mesh model in the folding sequence,then the mesh model is simplified in the high curvature and low curvature region.This algorithm not only takes into account the volume changes of the simplified model,but also can well reflect the changes in the geometry of local surface meshes.Then the algorithm can dynamically simply the mesh model by implementing progressive mesh method.Meanwhile,upon Visual Studio 2010 platform,developed a model to model simplification software combined with the excellent three-dimensional graphics library OpenGL,and two algorithms deletion into the software.This software can handle models which are PLY file format,and has a simple human-computer interaction and rendering functions.Experimental results show that the model-simplified software we develop based on OpenGL can success import PLY files,and compared to the QEM edge collapse algorithm,the improved edge collapse algorithm is better display the original algorit hm,the geometry of the model get a better maintained.This model-simplified software achieves our research purpose and running perfect.