1. A Hierarchical Approach to Interactive Motion Editing for Human-like Figures Jehee Lee Sung Yong Shin KAIST Jehee Lee Sung Yong Shin KAIST

2. Motion Editing Realistic motion data motion capture technologymotion capture technology commercial librarycommercial library Reuse available motion clips interactive motion editinginteractive motion editing motion adaptationmotion adaptation Realistic motion data motion capture technologymotion capture technology commercial librarycommercial library Reuse available motion clips interactive motion editinginteractive motion editing motion adaptationmotion adaptation

3. Spacetime Formulation Spacetime constraints [Witkin and Kass 88] [Cohen 92] [Gleicher 98] important features of the original motionimportant features of the original motion new features to be accomplishednew features to be accomplished To find a new motion satisfying given constraintssatisfying given constraints preserving original characteristicspreserving original characteristics Spacetime constraints [Witkin and Kass 88] [Cohen 92] [Gleicher 98] important features of the original motionimportant features of the original motion new features to be accomplishednew features to be accomplished To find a new motion satisfying given constraintssatisfying given constraints preserving original characteristicspreserving original characteristics

4. Video Direct manipulation with spacetime constraints Video

5. Basic Idea Structure of motion sequences Intra-frame relationshipIntra-frame relationship –satisfying constraints –by inverse kinematics Inter-frame relationshipInter-frame relationship –avoiding jerkiness –by curve fitting Structure of motion sequences Intra-frame relationshipIntra-frame relationship –satisfying constraints –by inverse kinematics Inter-frame relationshipInter-frame relationship –avoiding jerkiness –by curve fitting

6. Motion Representation Configuration of articulated figures linear components :linear components : angular components :angular components : Configuration of articulated figures linear components :linear components : angular components :angular components : The position of the root segment The orientations of the body segments The orientation of the root segment

7. Motion Displacement Mapping [Bruderlin and Williams 95] [Popovic and Witkin 95]

8. Motion Displacement Mapping Representation of displacement maps an array of spline curvesan array of spline curves over a common knot sequenceover a common knot sequence Flexibility in representation hard to determine knot densityhard to determine knot density adaptive refinement is neededadaptive refinement is needed Representation of displacement maps an array of spline curvesan array of spline curves over a common knot sequenceover a common knot sequence Flexibility in representation hard to determine knot densityhard to determine knot density adaptive refinement is neededadaptive refinement is needed

9. Adaptive Refinement Multilevel or Hierarchical B-splines [Lee, Wolberg and Shin 97] [Forsey and Bartels 95] sum of uniform B-spline functionssum of uniform B-spline functions coarse-to-fine hierarchy of knot sequencescoarse-to-fine hierarchy of knot sequences Multilevel or Hierarchical B-splines [Lee, Wolberg and Shin 97] [Forsey and Bartels 95] sum of uniform B-spline functionssum of uniform B-spline functions coarse-to-fine hierarchy of knot sequencescoarse-to-fine hierarchy of knot sequences

10. Multilevel B-Spline Fitting

11. Hierarchical Motion Fitting Hierarchy of successively refined motions successively finer displacement mapssuccessively finer displacement maps at each level in the hierarchy,at each level in the hierarchy, –to compute displacements at constrained frames –to derive a displacement map by curve fitting Hierarchy of successively refined motions successively finer displacement mapssuccessively finer displacement maps at each level in the hierarchy,at each level in the hierarchy, –to compute displacements at constrained frames –to derive a displacement map by curve fitting

12. Knot Spacing Direct manipulation larger spacing yields wider range of deformationlarger spacing yields wider range of deformation Precision control precision depends on the density of the finest knot sequenceprecision depends on the density of the finest knot sequence Direct manipulation larger spacing yields wider range of deformationlarger spacing yields wider range of deformation Precision control precision depends on the density of the finest knot sequenceprecision depends on the density of the finest knot sequence

13. Inverse Kinematics Constrained optimization with fewer variables one-variable parameterization for arms and legsone-variable parameterization for arms and legs Constrained optimization with fewer variables one-variable parameterization for arms and legsone-variable parameterization for arms and legs “elbow circle” [Korein and Badler 82] “elbow circle” [Korein and Badler 82]

14. Video Examples of Motion Adaptation Video

15. Summary Hierarchical motion fitting hierarchical representationhierarchical representation –provides adaptive refinement –allows to edit motion at any level of detail interactive performanceinteractive performance easy to implementeasy to implement Hierarchical motion fitting hierarchical representationhierarchical representation –provides adaptive refinement –allows to edit motion at any level of detail interactive performanceinteractive performance easy to implementeasy to implement

16. Discussion and Demonstration at Creative Application Lab Discussion and Demonstration at Creative Application Lab