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A Physically-Based Motion Retargeting Filter. SEYOON TAK HYEONG-SEOK KO ACM TOG (January 2005) 9557526 方奎力. Outline. Introduction Approach Result Conclusion. Introduction. Constraints-based motion edit Kinematically constrains Dynamic constrains Segment weights 、 joint strengths ….
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A Physically-Based Motion Retargeting Filter SEYOON TAK HYEONG-SEOK KO ACM TOG (January 2005) 9557526 方奎力
Outline • Introduction • Approach • Result • Conclusion
Introduction • Constraints-based motion edit • Kinematically constrains • Dynamic constrains • Segment weights、joint strengths…
Introduction • Novel constraints-based motion edit • Per-frame algo. -> Kalman filter • May velocity relationship between constrains -> least-squares filter
Approach • Formulation Constraints • Kalman Filter • Least-Squares Filter
Approach I. (Formulating constraints) • Kinematics • Balance • Torque limit • Momentum
Approach I. (Formulating constraints) • Kinematics • Locations e
Approach I. (Formulating constraints) • Balance • Human are two-legged creatures -> balance
Approach I. (Formulating constraints) • Balance
Approach I. (Formulating constraints) • Torque limit
Approach I. (Formulating constraints) • Momentum • Linear momentum • Angular momentum
Approach II. (Kalman filter) • Kalman filter
Approach II. (Kalman filter) • Unscented Kalman filter (UKF) • Better handle severe nonlinearity
Approach II. (Kalman filter) • Unscented Kalman filter (UKF) • Process model • Measurement • Measurement model
Approach II. (Kalman filter) • Unscented Kalman filter (UKF) • Vx : process noise covariance
Approach II. (Kalman filter) • Unscented Kalman filter (UKF) • Construct (2n+1) sample point
Approach II. (Kalman filter) • Unscented Kalman filter (UKF) • Transform sample point through measurement model
Approach II. (Kalman filter) • Unscented Kalman filter (UKF) • Predicted measurement innovation covariance cross-covariance measurement noise covariance
Approach II. (Kalman filter) • Unscented Kalman filter (UKF) • Final state update
Approach III. (Least squares filter) • Independent variables • Curve fitting procedure
Approach III. (Least squares filter) • Formulate B-spline curve
Approach III. (Least squares filter) • Over-constrained linear system
Conclusion • Adv. • Per-frame algo -> Stable interactive rate • Constraints-base • Balance constrains
Conclusion • Disadv. • Noise covariance • Cost of least square filter • Balance constrains -> You can’t fall