The Research And Implementation Of3D Stratum Model To Simulate Excavating

Over the past few years, there are lots of study about how to set up the3D stratamodel, and using Delaunay triangular mesh to build three-dimensional stratum TINmodel also gradually become the mainstream of research.. But the real core ofthree-dimension stratum display is cutting the three-dimension stratum arbitrary.The coreof my study is cutting the three-dimension stratum arbitrary, and to get rid of the insidegeological structure of cutting polygon, carrying out the effect of cutting the3D stratummodel.This paper introduces the definition of Delaunay triangular mesh and its twocharacteristics at first. They are max-min angle characteristics and empty circumcirclecharacteristics. It points out the superiority of the Delaunay triangular mesh being used asbuilding3D strata TIN model. And it summarizes three commonly used methods ofcreating the Delaunay triangular mesh: point by point insertion method, triangular meshgrowth method, divide and conquer method. It analyzes the advantages anddisadvantages of these three kinds of commonly used methods, detailedly comparestheir performance at all aspects. Finally, it selects triangular mesh growth method as thebasic method of this paper considering all facts.After comparing the methods of buildingDelaunay triangular mesh without constraint, this paper introduces Delaunay triangularmesh with constraint. As my study imitating excavating3D stratum model, buildingDelaunay triangular mesh with constraint island, it explain some concepts and charactersabout that. And it detailedly introduces some classic algorithms of embedding constraintline which been used widely at present and clarifies their respective implementation steps.It also analyzes the disadvantages of these methods, thus To put forward a kind ofalgorithm that building Delaunay triangular mesh with constraint island regionally.At last, according to selecting data points of excavated model, defining theconstraint boundary, reconstructing model, mapping model, this paper introduces thealgorithm that building Delaunay triangular mesh with constraint island regionally. Bydefining all the edges of the cutting polygon as constraint line, it divides stratum model into two areas by cutting polygon: inside and outside. Using the improved triangularmesh growth method, it can build Delaunay triangular mesh with constraint regionallyand staged. By adding limiters at mapping model stage, it can get the effect of3Dstratum model to simulate excavating.