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
Thedefaulteasy-in/easy-outblendingparameterscanbemodi edbydouble-clickinginthedesiredblendingintervaloftheConcatenation
Window.
Figure14:Blendingintervals(detailfromConcatenationWindow).
Blending
Blendingisthelasttypeofmotionoperationde nedintheprimarysetoftheprototypesystem.
AsintheConcatenationWindow,allmotionsselectedbytheuserareplacedinacanvas,providingaglobalviewoftheoperation.Forblending,however,newobjectswereintroducedtoassistinthespeci cation.
Thesenewobjectsarethetime-markers,andtheirpurposeistosynchronizekeypointsinthecombinedmotions.Forexample,whencombiningtwodi erenttypesofwalkmovements,itisdesirablethatthefeetreachthegroundatthesameinstantinbothmotions,otherwisestrangeresultscanbeproduced.
Figure15showsasnapshotofablendingoperationbetweenthreedi erentmotions.Thetime-markers(detailfromFigure15)wereusedtoestablishacorrespondencebetweenthekeystepsinthecombinedmotions.
Thissynchronizationprocesswillreparametrizethemotionsaccordingtothepositionofthetime-markers,matchingtheiroccurrenceintime.Todothat,algorithmsbasedontimewarpingareused.Agoodexamplecanbefoundin[9].
3.4Higher-LevelInterfaceObjects
Tocompletetheinterfacedescription,wepresentotherobjectsthatareimpor-tanttocreateapowerfulanimationenvironment.