ABSTRACT

Whatarethemajordesignelementsfordevelopingreconfigurablegraphical simulationsystems?Whattoolsshouldweprovidetheuserfordefiningand interactingwithobjectsandagentsinvirtualenvironmentsatvaryinglevelsof complexity?Idescribeasetofabstractioncategories-structural,procedural, functional,andagentabstractions-neededforrepresentingandcontrollingsimulatedobjectsandagents,andIdiscusshowprogramming,anddirectmanipulationorguidingtechniques,canbeusedtoaffordinteractiveaccesstographical simulationsatappropriatelevelsofabstraction.Thelowestlayerofabstractionis representedbyobjectsandstructureswithnoproceduralattachment,andis calledthemachinelevel.Attheotherextreme,thetasklevel,guidingandprogrammingtoolsinteractwithagentsthroughtheirrepertoireofbehaviors.Task levelinteractionemergeswhenguidingandprogrammingtechniquesareapplied athigherlayersofabstraction.Idescribehowprogrammingandguidingcanbe usedwitheachofthefourclassesofabstraction-ascontrolinstrumentsoras definitionandeditingtools.Thisanalysisisillustratedwithexamplesfrompreviousandcurrentgraphicalsimulationsystems,andprovidesaconceptualblueprintforthedesignandimplementationofgraphicalsimulationsystemsfora varietyofapplications.