AC3D-技术手册.pdf

AC3D-技术手册.pdf

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Version6.8UserManualCopyrightInivisLimited2011AC3DManualfile:

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32AMWelcometoAC3DAC3Disdesignedtomaketheconstructionof3Dobjectsfastandeasy.Itisusedtocreate3Dmodelsforsimulations,games,renderingray-tracedimagesandforscientificandgeneraldatavisualization.AC3Drunsonawiderangeofstandardhardwareandisavailableacrossanumberofpopularplatforms.AC3DterminologyVertexAvertexisasinglepointin3dspace.Itsspecifiedbythreecoordinatesx,yandz.Morethanonevertexcanoccupythesamepositionin3dspace.Avertexisalwaysownedbyasingleobject;theycannotbesharedbetweenobjects.AvertexisusuallypartofoneormoreSurfaces,butneednotbe.SurfaceAsurfaceinAC3Disasequenceofvertices.Surfacesareoneofthreetypes;polygons,linesorpolygonoutlines.Thetypeofasurfacedefineshowthesurfaceisdrawnandthiscanbeeasilychanged.Ifasurfaceissettobesingle-sided,itwillonlybevisiblefromthefront.Two-sidedsurfaceswillbevisiblefrombothsides.Itismoreefficienttodrawsinglesidedsurfacesandmakesmoresensewhenusedaspartofanobjectsuchasasphere（whereyoucantseetheothersideofthesurfaces）.Surfaceshaveamaterialattribute,whichdefinesthecolorandquality（forlightingpurposes）.EachvertexreferencedinasurfacehasanassociatedTextureCoordinate.Verticescanbesharedbetweensurfacesinthesameobject.SurfacenormalAsurfacenormalspecifiesthedirectionasurfaceisfacing.Normalsareusedinlightingcalculations.SurfacenormalsareautomaticallycalculatedbyAC3D.Asurfaceisdefinedasfacingthevieweriftheverticescanbeseeninananti-clockwisedirection.ObjectAnAC3Dobjectisalistofvertices,andsurfacesthatusethesevertices.Italsohasotherattributessuchasanameandtexture.GroupAgroupisaspecialobjectthathasnosurfacesorverticesbuthasotherobjectsaschildren.GroupsarecreatedbyselectingtwoormoreobjectsandselectingGroupfromtheeditmenuortoolbar.UsetheUngroupfunctiontoseparatetheobjects.Select-modeTheselectmodeallowscontroloverthelevelofeditinginAC3D.InVertex,individualverticescanbeselectedandadjusted.InSurface,operationsareperformedononeormoreselectedsurface.InObject,wholeobjectsareselectable.Thisallowsmanipulationofobjects,eveniftheyarepartofgroups.InGroup,selectingallorpartofanobjectautomaticallyselectsthetoplevelobject.MaterialAmaterialdefinesthecolorofasurfaceandalsotheattributesthatdefinethewayitwillreacttolighte.g.shininess.TextureGraphicalimagescanbemappedontothesurfacesofanobject.Theimagesareusuallyfromgraphicsfilessuchasgif,jpg,bmpetc.TexturecoordinatesWhenthevertexofasurfaceisdrawn,atexturecoordinatespecifiesthepositionofatextureimagetomaptothatpoint.Atexturecoordinateisatwodimensional（u,v）valuewhichdefinesthepointonthe2Dimage.AC3DManualfile:

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32AMBoundingboxWhenyoumakeaselectionofobjects,surfacesorvertices,agreenboxoutlinesit.Youcandrag,resizeorrotatethisboxtoadjustthecontentsGettinghelpUserinterfacecomponentsinAC3Dhaveballoonhelp.Smalltooltipwindowswillpopupwhenthemousepointerrestsoverabuttonorfieldlabel.ThisfeaturecanbeswitchedofffromFile-Settings.Whenbrowsingthroughthemenuitems,thefunctiononeachitemisdescribedinthemessagetextatthebottomoftheAC3Dwindow.AC3DManualfile:

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32AMAC3Dhasacontrolpanelontheleft,plus4viewwindows.Theresalsothemenuandtoolbaratthetopandaninformationbaralongthebottom.ControlpanelThisiswherethemaincontrolsovertheselectionanddrawmodesarelocated.Italsocontainsthesurface-typecontrols,thepaletteofmaterialsandtheobjectnamefield.Thetopofthecontrolpanelshowsinformationaboutthecurrentselection.Whenthemouseisbeingusedtointeractwithmodels,thisareawillalsodisplaycurrentpositions,distancesmovedandotherrelatedinformation.ToolbarThiscontainsbuttonsforsomeofthemostcommonlyusedfunctions.AllselecteverythingNonecleartheselectionDupduplicatetheselectionCut/Copy/PasteuseAC3DsinternalclipboardGroup/Ungroupputselectedobjectsintoagroup/removethegroupobjectFlipx/y/zflipthesectionaboutthisaxis200%/50%/+10%/-10%scaletheselectionuniformlyMaximizeasinglevieworviewALLtogetherViewwindowsBydefault,AC3Dstartswiththreetwo-dimensional（2Dorthographic）viewwindowsandasinglethree-dimensional（3D）window.ThedefaultviewwindowsshowFront,Left,Topand3Dcameraanglesontothemodelspace.Thedividersbetweenthe4viewwindowscanbedraggedtoresizetheviews.Individualviewsaremaximizedbyclickingontheviewbuttonsatthetoprightofthemainwindow（alternatively,theF1-F5keyscanbepressedtoswitchbetweenthedifferentviewconfigurations）.Themainwindowsize/positionandothersettingsaresavedwhenAC3Dexits.AC3DManualfile:

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32AMTheconfigurationoftheviewsthatAC3DstartsupwithcaneasilybechangedfromthemenuViews-Configureviews.Eachviewwindowhasanindividualmenuatthetop.Thiscontainsthemenufortheviewangle（Camera）,changingtheviewpoint（e.g.focusingonthecurrentlyselectedarea）andsomemisc.controlsthataredependentonwhetherthewindowissetto2Dor3D.TheCameraanglecanbechangedatanytime.Thisisusefulif,forexample,youneedtoview（orworkon）amodelfromtheunderside（bottomview）.Theiconsontherightofeachview-menuallowyoutousethemousetonavigatearoundthe3Dspace,showacleanimage,andmaximizetheviewwindow.Spin（3Dviewsonly）pressanddragMove/Panview-pressanddragZoomin/outviewpressanddragInspectSwitchtoshowcleanimage（displaywithoutallsurfaceoutlines,grid,controlsetc）andchangetosimplenavigationmode.Maximize/minimizeviewbuttonThespin,move/panandzoombuttonarespecialcontrolsthatarehelddown（leftmousebutton）whilstthemouseisdragged.Theviewsadjusttheirviewpointasthemouseisdragged.AdditionalviewscanbecreatedfromthemenuViews-New-View.Unlike2DCADprograms,thespacepresentedintheAC3Dviewwindowsisnotlikeafinitepieceofpaperwhichhasalimitandedges.Youcanmoveviewpointsjustlikeapersonmovesaroundinreal3Dspace.Therearenorealedgestotheavailablespace（apartfromreachingcomputationallimits）.Orthographic（2D）viewsWhenaviewcameraissettoFront,Back,Top,Bottom,LeftorRight,theviewisnon-perspectiveorthographic2D.Anorthographicviewshowsaviewparalleltoasingleaxis.TheitemsonthemainOrthmenucontrolhowviewssettothesecameramodesaredrawnandwhatcomponentsarevisible.Forthesesettings,allOrthwindowsworktogethere.g.switchingfromfilledtowireframeappearanceinoneOrthwindowcausesallotherOrthwindowstoalsobesettowireframe.Althoughitsusefulsometimestoworkinasingleview,seeingallthewindowsatoncecanbeveryhelpfulwhenpositioningobjectsandlayingoutscenes.Navigatingin2DviewsUsethemousetopanorzoomanorthview.Thekeyboardarrowkeyspanandcontrol+up/downzoomsinandout.Holdingdownashiftkeyincreasesthemovement/zoomdistance.ThegridsIntheorthographicwindowstherearetwogrids-thedrawgrid（majorlines）andthesnapgrid（minorlines）.BothcanbesetfromFile-Settingsandtheirdisplaycanbetoggledon/offbyselectingGridfromtheOrthmenu（orpressingthegkeywhenfocusedinanorthwindow）.TheSnapgridisshownbythinvisualguidelines;thedrawgridusesthickerlines.IfGridsnapisswitchedon,moving/resizing/creatingmousemovementswillbealignedtothenearestsnapgridpoints.AC3DManualfile:

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32AMThegridscanbeconfiguredtodisplayunitsofanysizee.g.foreighthsofaninch,themajordrawgridwouldbesetto1.0andthesnapgridsetto0.125（1/8th）.UsingBackgroundImagesAnyorthographic（2D）windowcandisplayabackgroundimage.Thiscanbeusefulfortracingshapesorlayingoutobjectsinrelationtoascannedimagee.g.aplanormap.BackgroundimagesaresetandunsetfromtheOrthmenuatthetopofanorthographicwindow.AllimageformatsthataresupportedbyAC3Dstextureloaderscanbeusedasbackgroundimages.Backgroundimageswillscaleandmovewiththeviews.Bydefaulttheimagewillbecenteredontheorigin.Thescaleandpositionofthebackgroundimageisadjustedbyusingaltandthecursorkeys.Altandthecursorkeysrepositiontheimage,whilstAlt+Shiftpluscursorup/downscaletheimage.DetailsofbackgroundimagesarecurrentlynotsavedwithmodelsorwhenAC3Dexits.3DviewsA3Dviewwindowdisplaysthecurrentmodelinathreedimensionalperspectiveandchangesinstantlywhenanymodificationsaremadetothecurrentmodel.Themain3Dmenu（atthetopofthemainAC3Dwindow）containscontrolstoswitchvisibilityofmanyattributeswithinthe3Dwindow.Changingthesecontrolsaffectsall3Dwindowswithintheprogram.A3dgridisavailable-togglewithg.ThegridliesontheXZplane（floor）.wtogglesbetweenwireframeandfilleddrawing,ttogglestextures.ltogglesthefixedlight.Seethe3Dmenuformoreviewingoptions.Navigatingin3DTwonavigationmodesareavailableinthiswindowspinandwalk.Thesecanbeswitchedfromtheviewsown3Dmenuorbypressingthe1or2keyswhilstthepointerisinthe3Dwindow.SpinmodeButtoncontrolsattopofviewforspin,panandzoomFromkeyboard:

Spin-up/down/left/rightkeys,orAlt+leftmousebuttonZoomControl+up/downWalkmodeButtoncontrolsattopofviewforwalk/fly,panandtiltFrom