Reconstructing Personalized Anatomical Models for Physics-based Body - PowerPoint PPT Presentation

Reconstructing Personalized Anatomical Models for Physics-based Body Animation Petr Kadlecek* Alexandru-Eugen Ichim* Tiantian Liu Jaroslav Krivanek Ladislav Kavan * joint first authors

MOTIVATION 1. Build an anatomical rigged volumetric model from 3D scan data. 2. Animate through physics simulation. e.g. with MOCAP data. Reconstructing Personalized Anatomical Models for Physics-based Body Animation – P. Kadlecek, A.E. Ichim, T. Liu, J. Krivanek, L. Kavan

MOTIVATION Reconstructing Personalized Anatomical Models for Physics-based Body Animation – P. Kadlecek, A.E. Ichim, T. Liu, J. Krivanek, L. Kavan

MOTIVATION Reconstructing Personalized Anatomical Models for Physics-based Body Animation – P. Kadlecek, A.E. Ichim, T. Liu, J. Krivanek, L. Kavan

MOTIVATION Reconstructing Personalized Anatomical Models for Physics-based Body Animation – P. Kadlecek, A.E. Ichim, T. Liu, J. Krivanek, L. Kavan

RELATED WORK Creating and Simulating Computational Skeletal Muscle from DYNA, SCAPE, Anatomy Transfer, Bodybuilding, the Visible Human Data Set, Pons- Moll et al., SG’15 Anguelov et al., SG’05 Dicko et al., SG’13 Saito et al., SG’15 Teran et al., VCG’05 Data-driven Forward Simulation Only An asymptotic numerical Capture and Modeling of method for inverse elastic Deformation Capture and Non-Linear Heterogeneous shape design, Modeling of Soft Objects, Soft Tissue, Chen et al., SG’14 Bickel et al., SG’09 Wang et al., SG’15 Inverse Material Modeling Reconstructing Personalized Anatomical Models for Physics-based Body Animation – P. Kadlecek, A.E. Ichim, T. Liu, J. Krivanek, L. Kavan

CONTRIBUTIONS • First method to reconstruct a fully physics-based subject-specific anatomical model • New elastic potential more suitable for solving the inverse reconstruction problem • Use different material types and growth models • Collisions at reconstruction time Reconstructing Personalized Anatomical Models for Physics-based Body Animation – P. Kadlecek, A.E. Ichim, T. Liu, J. Krivanek, L. Kavan

PIPELINE Reconstructing Personalized Anatomical Models for Physics-based Body Animation – P. Kadlecek, A.E. Ichim, T. Liu, J. Krivanek, L. Kavan

TEMPLATE MODEL Tetrahedral mesh Rigged with a skeleton. The skeleton offers both pose and character-specific parametrization. The bones and tetmesh talk through sampled bone vertices. Reconstructing Personalized Anatomical Models for Physics-based Body Animation – P. Kadlecek, A.E. Ichim, T. Liu, J. Krivanek, L. Kavan

TEMPLATE MODEL Types of materials (non-conformally embedded): • Bone Muscles and tendons • • Generic Soft Tissue / Fat Muscle fiber directions. Reconstructing Personalized Anatomical Models for Physics-based Body Animation – P. Kadlecek, A.E. Ichim, T. Liu, J. Krivanek, L. Kavan

PHYSICS-BASED SKINNING Solve the optimization problem: Gravity Skeletal Motion Collisions Deformation Energy Pose changes Bone lengths Reconstructing Personalized Anatomical Models for Physics-based Body Animation – P. Kadlecek, A.E. Ichim, T. Liu, J. Krivanek, L. Kavan

INVERSE PHYSICS REGISTRATION Scan Targeting Skinning Energy (at steady state) Muscle growth orthogonal to fibers Fat grows freely in the remaining space Growth Priors Reconstructing Personalized Anatomical Models for Physics-based Body Animation – P. Kadlecek, A.E. Ichim, T. Liu, J. Krivanek, L. Kavan

INVERSE PHYSICS REGISTRATION Reconstructing Personalized Anatomical Models for Physics-based Body Animation – P. Kadlecek, A.E. Ichim, T. Liu, J. Krivanek, L. Kavan

RESULTS – GROWTH MODEL Reconstructing Personalized Anatomical Models for Physics-based Body Animation – P. Kadlecek, A.E. Ichim, T. Liu, J. Krivanek, L. Kavan

RESULTS – INVERSE COLLISIONS Reconstructing Personalized Anatomical Models for Physics-based Body Animation – P. Kadlecek, A.E. Ichim, T. Liu, J. Krivanek, L. Kavan

RESULTS – INVERSE GRAVITY Reconstructing Personalized Anatomical Models for Physics-based Body Animation – P. Kadlecek, A.E. Ichim, T. Liu, J. Krivanek, L. Kavan

ANIMATION Volume-preserving muscle contraction along fibers Inertia Term Reconstructing Personalized Anatomical Models for Physics-based Body Animation – P. Kadlecek, A.E. Ichim, T. Liu, J. Krivanek, L. Kavan

RESULTS – MOCAP ANIMATION Reconstructing Personalized Anatomical Models for Physics-based Body Animation – P. Kadlecek, A.E. Ichim, T. Liu, J. Krivanek, L. Kavan

RESULTS – INERTIAL EFFECTS Reconstructing Personalized Anatomical Models for Physics-based Body Animation – P. Kadlecek, A.E. Ichim, T. Liu, J. Krivanek, L. Kavan

RESULTS – MUSCLE CONTRACTION Reconstructing Personalized Anatomical Models for Physics-based Body Animation – P. Kadlecek, A.E. Ichim, T. Liu, J. Krivanek, L. Kavan

LIMITATIONS AND FUTURE WORK • Only capture large- and medium-scale details. The quality of the results depends on the template model. • Muscle-bone interactions, e.g., collisions, sliding • Due to the complexity of the optimization problem, we cannot scale to fitting more than 10 scans at the same time. • Can only handle real scans. Fantastical creatures might need a different template model. Estimate the muscle contractions/forces from the scans. • • Perform reconstructions from sequences of scans, where the body is not in a steady-state. Biomechanics and computer graphics • Reconstructing Personalized Anatomical Models for Physics-based Body Animation – P. Kadlecek, A.E. Ichim, T. Liu, J. Krivanek, L. Kavan

Reconstructing Personalized Anatomical Models for Physics-based Body Animation Thank you for your attention. Petr Kadlecek* Alexandru-Eugen Ichim* Tiantian Liu Jaroslav Krivanek Ladislav Kavan * joint first authors