Research And Application About Simplification Algorithm Of Grid Model Based On OSG

In recent years,the application of 3D models in transportation,industrial production and construction and other industries has become more and more extensive,and because of its own advantages in greatly restoring the real environment,it has begun to gradually replace the past 2D plane models.With the development of science and technology,the ways to obtain three-dimensional models(such as high-definition cameras,laser scanning technology,etc.)have become advanced,and the three-dimensional models constructed from this have become more and more refined.But in fact,the highly detailed model brings massive amounts of data,which will affect the transmission,loading and display of the 3D model in the computer.Therefore,it is an indispensable processing step to simplify the data volume of the model without affecting the visual effect of the entire model.In view of the above background,this article first compares the advantages of various types of 3D models,and determines that the triangle mesh model is the simplification goal.Secondly,after analyzing the current various simplification algorithms,the edge collapse algorithm is selected as the research basis for improving the simplification algorithm.As far as the existing simplification algorithm is concerned,some details of the original model are often ignored when simplification.Especially when the model is greatly simplified,it often makes the simplified model unable to maintain the original shape,resulting in Simplify the drop in effect.For the above situation,this paper adds the face importance parameter to the collapse cost in the edge collapse algorithm,and calculates the new collapse cost to improve the algorithm.This parameter consists of three parts.First,calculate the angle between the two adjacent planes of the collapsed edge,and set the relationship to the parameter as the closer the angle is to ?,the smaller the parameter.Secondly,calculate the average area of the triangular surfaces around the two vertices of the collapsed edge,which is proportional to the surface importance parameter.Then calculate the similarity between the normal vector of the two vertices and the normal vector of the surrounding plane respectively,and compare it with the method of calculating the Euclidean distance.The smaller the value,the more similar the normal vector of the point and the normal vector of the surrounding plane,and the surface importance parameter The smaller the value.Finally,these three parts constitute the surface importance parameter,and then add it to the collapse cost in the existing edge collapse algorithm,so that the new algorithm will first simplify the relatively flat area in the 3D model.In this way,when the overall simplification rate remains unchanged,the simplification priority of the detailed feature areas in the three-dimensional model is reduced,so that the original structure of the model can be maintained and the simplification effect of the three-dimensional model can be improved.The innovation of this paper is to put forward the calculation method of adding the surface importance parameter to the collapse cost,and to verify it by experiments.In the experiment,two models representing less and more data were tested,and they were simplified with different simplification rates respectively,which proved the effectiveness of the algorithm in this paper in improving the simplification effect.However,the experiment also found the defects of the algorithm in this paper,that is,due to the process of adding more calculation parameters,the algorithm in this paper has a slight increase in simplification time,but the impact of this time increase is small and belongs to an acceptable range.