Dynamic Response for MotionCapture AnimationDynamic Response for MotionCapture Animation
Victor B. Zordan
Anna Majkowska
Bill Chiu
Matthew Fast
Riverside Graphics Lab University ofCalifornia, Riverside
OutlineOutline
•Introduction
•Motion Selection
•Transition Motion Synthesis
•Implementation
•Conclusion
IntroductionIntroduction
•General adaptation and re-use of the data is limitedby the available techniques for editing and modifyingdata in controllable ways.
•Physical models commonly used to responsivity tocharacters by generating modifications.
•But, the effects of an impact are over, there are nogeneral schemes to move the simulation in ameaningful way and return the simulation to motioncapture control.
•Automatically computes a dynamic reaction to anunanticipated impact and returns the character to anavailable motion from a capture repository for theremainder of the dynamic response to the interaction.
•Two critical components
–Search engine compares initial simulated response withreaction segments from a motion library.
–Joint-torque controller that actuates the simulation to reachthe desired posture.
Motion Selection (Motion graphs)Motion Selection (Motion graphs)
•Creating response
–Find transition-to motion capture sequence form repository.
–Compare simulated data with sequences in motion library.
•Define sample frame as vector:
•Distance D between windows is defined as:
•To capture the dynamic properties.
–Assign high weights to the trunk parts.
–Reduce the problem of sliding ground contact.
•To increase the efficiency of the search function
–Pre-process database to find unique frames.
Transition Motion SynthesisTransition Motion Synthesis
•Compute transition motion with two goals:
–React in a physically plausible manner consistent with foundmotion.
–Meet the desired state as closely as possible.
•Compute torques as
•[Zordan & Hodgins 2002] - Motion capture-driven simulationsthat hit and react.
•Timing is critical to make the character’s actionappear realistic.
•Generating and blending motion capture data
–Interpolation to remove remaining disturbances.
–Interpolate linearly the root node offset.
–For rotation, interpolates by slerp quaternion.
–Using simple linear weighting.
ImplementationImplementation
•To create believable exchanges between characters.
–Heavy impact-based interactions require simulation of boththe recipient and the deliverer of the impacts generated.
•Simply following the completely simulated motion fora small number of frames after the impact.
•Then blending back to the same original motionthrough interpolation lead to a convincing attackmotion.
•Motion capture reactions
–Pushed were made from the front, side and back withreaction including balanced recovery that required minimalfoot repositioning.
•Range of such responses starting from a single pairof motion clips found by simply varying the facingdirection of one of the characters.
ConclusionConclusion
•Takes advantage of the concept of the describedburst following an impact without the need for acomplicated implementation.
•Important contribution is use of a controller acts inaccordance with the upcoming motion.
–Avoid an unconscious look for the character.
QuestionQuestion
Thanks for your listening