Severaldifferentstrategiesof3Dmodelingareadoptedfordifferentkindsofmanmadeobjects.Firstly,forthosemanmadeobjectswithregularstructure,if2Dinformationisavailableandelevationinformationcanbeobtainedconveniently,then3Dmodelingofthemcanbeexecuteddirectly.Secondly,forthosemanmadeobjectswithcomplicatedstructurecomparativelyandrelatedstereoimagespaircanbeacquired,inthelightoftopology-based3Dmodelwefinish3Dmodelingofthembyintegratingautomaticandsemi-automaticobjectextraction.Thirdly,forthemostcomplicatedobjectswhosegeometricalinformationcannotbegotfromstereoimagespaircompletely,weturntotopological3DmodelbasedonCAD.
