Abstract. This paper proposes a new user interface paradigm for motion capture based animation systems, providing intuitive and efficient ways to visualize the main motion capture concepts and operations. A prototype system was built, implementing the prop

Inoursystem,wehavecreatedaninterfaceobjectwhosepurposeistoactasamotionorganizer,providingaglobalperceptionofallmotionsplacedonit.WecalledthisobjecttheMotionScratchPad(Figure

8).

Figure8:MotionScratchPad-themotionorganizer.

UsingtheScratchPad,theusercanchooseseveralmotionsandorganizethemintheobjectcanvas.Allmotionscanbeindividuallyplayedorresized,andtheusercandropthemtothemotionoperations.TheScratchPadisactuallythegatewaybetweentheinputandtheprocessingmodules.

TheScratchPadisthecontainerwheremotionfragmentsarestored,waitingtobeused.

JointCurves

Jointcurvesarethebasiccomponentsofmotion.Theyarevisuallyrepresentedbyaninterfaceobjectthatdisplayscurveshape.Italsoprovidesnumericin-formationaboutthedi erentdatachannelsateachframe(i.e.,threepositionandorientationvalues,foreachjointcurve).ThevisualrepresentationofajointcurveisshowninFigure9.

Withthisrepresentation,itisstraightforwardtoimplementseveralcurveeditingtechniques[9][11],allowingapreciseandinteractivecontrolofthecurveshape.Foreachjointoftheactor,theremaybeseveraljointcurves(oneforeachDOF)attachedtoit.Thesecurvesaregroupedinainterfaceobject,theJointCurvesWindow,thato ersaglobalviewofthecurves,andhasadirectconnectionwiththeskeletongraphwindow.Whenajointisselectedinthegraphwindow,itscurvesaredisplayedandusefulinformationisprovided,asshowninFigure10.