简介:Thissurveyreviewstherecentdevelopmentofgradientdomainmeshdeformationmethod.Differenttootherdeformationmethods,thegradientdomaindeformationmethodisasurface-based,variationaloptimizationmethod.Itdirectlyencodesthegeometricdetailsindifferentialcoordinates,whicharealsocalledLaplaciancoordinatesinliterature.BypreservingtheLaplaciancoordinates,themeshdetailscanbewellpreservedduringdeformation.DuetothelocalityoftheLaplaciancoordinates,thevariationaloptimizationproblemcanbecastedintoasparselinearsystem.Fastsparselinearsolvercanbeadoptedtogeneratedeformationresultinteractively,oreveninreal-time.Thenonlinearnatureofgradientdomainmeshdeformationleadstothedevelopmentoftwocategoriesofdeformationmethods:linearizationmethodsandnonlinearoptimizationmethods.Basically,thelinearizationmethodsonlyneedtosolvethelinearleast-squaressystemonce.Theyarefast,easytounderstandandcontrol,whilethedeformationresultmightbesuboptimal.Nonlinearoptimizationmethodscanreachoptimalsolutionofdeformationenergyfunctionbyiterativeupdating.Sincethecomputationofnonlinearmethodsisexpensive,reduceddeformablemodelsshouldbeadoptedtoachieveinteractiveperformance.Thenonlinearoptimizationmethodsavoidtheuserburdentoinputtransformationatdeformationhandles,andtheycanbeextendedtoincorporatevariousnonlinearconstraints,likevolumeconstraint,skeletonconstraint,andsoon.Wereviewrepresentativemethodsandrelatedapproachesofeachcategorycomparativelyandhopetohelptheuserunderstandthemotivationbehindthealgorithms.Finally,wediscusstherelationbetweenphysicalsimulationandgradientdomainmeshdeformationtorevealwhyitcanachievephysicallyplausibledeformationresult.
简介:Itisachallengingproblemofsurface-baseddeformationtoavoidapparentvolumetricdistortionsaroundlargelydeformedareas.Inthispaper,weproposeanewrigidityconstraintforgradientdomainmeshdeformationtoaddressthisproblem.Intuitivelytheproposedconstraintcanberegardedasseveralsmallcubesdefinedbythemeshverticesthroughmeanvaluecoordinates.Theuserinteractivelyspecifiesthecubesintheregionswhicharepronetovolumetricdistortions,andtherigidityconstraintscouldmakethemeshbehavelikeasolidobjectduringdeformation.Theexperimentalresultsdemonstratethatourconstraintisintuitive,easytouseandveryeffective.
简介:该文在k—Mesh子网连通概念的基础上提出了三维Mesh网络中局部k—Mesh子网弱连通的概念,证明了局部k—Mesh子网弱连通的三维Mesh网络存在全局连通性。基于局部k—Mesh子网弱连通的三维Mesh网络提出了单播、广播容错路由算法。这些算法提高了容错能力且是基于局部信息的,因而具有很好的实际意义。
简介:随着当代科学技术的快速发展,无人机在性能和功能上都有很大的提升,这使得无人机在军用和民用两个领域上的应用都更加广泛。为了更好地传达任务指令,有必要对无人机自组网传输性能进行改进,结合分布式编码感知路由协议的不足和无人机自组网的特点,针对性地提出改进型分布式编码感知路由协议。仿真结果表明,改进型分布式编码感知路由能够有效地提高无人机自组网的吞吐性能。