nicolas pronost
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Definition and realisation of modeling methods and motion computation algorithms for virtual humans. Nicolas Pronost. Thursday 7 December 2006. Where are they found ?. Animation. Video games Movies. Motion sciences. Biomechanics Medicine, Health Sports. Robotics. Bipedal robot. - PowerPoint PPT PresentationTRANSCRIPT
Definition and realisation of modeling methods and motion computation algorithms for virtual humans
Nicolas Pronost
Advisor : Bruno Arnaldi
Co-advisor : Georges Dumont
Team : IRISA - SIAMES
Thursday 7 December 2006
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 2
Where are they found ?
Animation
Motion sciences
Robotics
Anthropology
Simulation
Video games Movies
Biomechanics Medicine, Health Sports Bipedal robot
Modern human Fossilised hominids Motion analysis Motion synthesis
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 3
Fondamental aspects
Modeling the human Symbolical and controlable representation Kinematical and physical properties
Modeling the motion Manipulable mathematical representation Dependant of the editing methods
Editing methods Based on motions laws Looking for generiness
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 4
Outline
Related works
Overview and motivations
Analysis / synthesis loop Kinematical adaptation
Evaluation of the dynamics
Forward dynamics synthesis
Conclusion and future work
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 5
Outline
Related works
Overview and motivations
Analysis / synthesis loop Kinematical adaptation
Evaluation of the dynamics
Forward dynamics synthesis
Conclusion and future works
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 6
Modeling a virtual human
Consensus between the anatomical reality and motion control Manipulation of the rotational degrees of freedom
Simplification through a hierarchical representation of rigid bodies [H-Anim 06]
Mechanical joints are perfect and the number of limbs is limited
l_mid_foot
r_hand_center
vt1
l_hip
l_kneel_anklel_subtala
r
l_toe
r_hip
r_kneer_ankle
r_subtalarr_mid_foot
r_toe
vl2
vl3
vt4
vt5
vt6
head_top
r_clav
l_hand_center
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 7
Biomechanical modeling
The physical properties describe the movement capacity of the limbs At least the masses and inertias
These data are avalaible from anthropometrical tables and computable from regression laws [Vaughan et al. 99]
Cadaverical data [Dempster 55, Winter 90]
Gamma radiography [Zatsiorsky 90]
Various definitions of limbs [Chandler et al. 75, De Leva 96]
Additionnal data Articular limits, muscular activations [Liu et al. 05], articular
elasticities
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 8
Modeling the motion
Motion is a sequence of postures Marey’s work [Marey 1894] on motion decomposition
Kinematical model Positions, velocities and acceleration Description of the possibility of motions
Static and quasi-static (kinetical) models Usefull for slow motions Balance of internal and external forces
Dynamical model Use of motor forces at joints
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 9
Methods of kinematics and inverse kinematics
Representation by splines [Zeltzer 82, Bruderlin and Calvert 93]
Local linearisation and secondary tasks [Boulic and Thalmann 92] [Tolani and Badler 96]
Motion editing methods
θ1
θ2
X
J X I J J z
X f ()
f 1(X)
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 10
Motion editing methods
Kinematics and control of the center of mass Important on quasi-static positions [Phillips 91]
Projection of the center of mass on the sustentation polygon [Boulic et al. 94]
Resolution using inverse kinematics with a priority formulation [Boulic et al. 97]
Conservation of the Zero Moment Point Point of null result of linear momentum of the limbs [Tak et al.
00]
Dynamics filtering of motions [Yamane and Nakamura 03]
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 11
Motion editing methods
Methods of dynamics and inverse dynamics Animation engine using a system of secondary order
differential equations [Hodgins 98]
Newton’s laws of motion and fondamental physical laws
Virtual works and Lagrangian formalism [Rémion 00]
A qÝ Ý q B q, Ý q E
Forcess ms aCGsMomentss I CGS
CGS
d
dt
K
Ý q i
K
qi
Ei
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 12
Manipulation of real movements
Real movements intrinsically have all of the information of the motion Correct perception of the realism from few positions of
caracteristical joints [Johansson 73]
Good realism of animations Low generiness
Usable database for generating new motions
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 13
Manipulation of real movements
Adaptation to new characters: retargeting
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 14
Manipulation of real movements
Adaptation to new characters: retargeting With different morphologies [Gleicher 98] thanks to
spacetime constraints
Use of intermediate skeletons [Monzani et al. 00, Ménardais 03]
Decomposition of articular trajectories into hierarchical splines [Lee and Shin 99]
Take account of muscular forces [Komura et al. 00]
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 15
Manipulation of real movements
Modification of the motion Frequential description of the articular trajectories and
deformation function [Bruderlin and Williams 95]
displacement map, conservation of the high frequencies
Description by key postures and interpolation on the parameters [Witkin and Popovic 95]
Interpolation of the deformation function (scale and translation)
m '(t) m(t)(t)
m '(t) a(t)m(t)b(t)
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 16
Manipulation of real movements
Combining motions The motion graphs [Kovar et al. 02]
node = key posture arc = possible transition
Motion blending Synchronisation by dynamic time warping [Bruderlin and
Williams 95] Blending by linear combinaison or weighted sum [Guo
and Robergé 96, Park et al. 02, Rose et al. 98, Ménardais et al. 04]
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 17
Manipulation of real movements
Motion database Efficient interpolation on simple motions [Wiley et Hahn
97]
Behavioral or frequential decomposition Fourier space [Unuma et al. 95]
Radial basis function [Rose et al. 96]
Hidden Markov chains [Brand and Hertzmann 00]
Static models using PCA [Bowden 00]
Physical simulations [Zordan et al. 05, Arikan et al. 05, Tang et al. 06]
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 18
Bipedal locomotion
The locomotion is a cyclic movement Decomposable into phases [Marrey 1894, Plat and Veil 83]
A step is a half cycle walk = sequence of single and double support phases run = sequence of single support and flying phases
Specific modeling of locomotion With cyclic state machines [Multon 98]
With deformed hypertorus from PCA [Martineau 06]
Large number of biomechanical data Articular trajectories [Alexander 84, Patla 91]
Support phases [Girard 87]
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 19
Summary
The analysis and the synthesis of virtual human motions [Gibet 02] answer to very differents constraints according to the application Compromise interactivity / realism / generiness
Kinematical corrections Interactivity of natural looking motions
Dynamical constraints Physical realism on specific motions
Spacetime resolution Offline and kinematical high control
Physics-based simulation Generic offline production of motions
Motions editing Balanced applications
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 20
Outline
Related works
Overview and motivations
Analysis / synthesis loop Kinematical adaptation
Evaluation of the dynamics
Forward dynamics synthesis
Conclusion and future works
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 21
Overview
Motivation : to study and to realise a process of modeling tools and motion computation Application to locomotion
Database of motions
Adaptation algorithm
Analysis of the dynamics
Synthesis by forward dynamics
adapted motion
resulting forces
synthetised motion
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 22
Outline
Related works
Overview and motivations
Analysis / synthesis loop Kinematical adaptation
Evaluation of the dynamics
Forward dynamics synthesis
Conclusion and future works
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 23
Kinematical adaptation
Adaptation algorithm
adapted motion
Database of motions
Analysis of the dynamics
Synthesis by forward dynamics
resulting forces
synthetised motion
Database of motions
Analysis of the dynamics
Synthesis by forward dynamics
resulting forces
synthetised motion
Database of motions
Speed profilesScaleAnatomical data
Footprints
Rest posture
Articular limits
Interpolations
- transversal
- frontal
- sagital
Time adjustement and Synchronisation
Post-treatments
Adapted motion
Kinematical and
Dimensionnal
Interpolation
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 24
Modeling the human
Definition of a kinematical chain with 11 dof Spherical joints at pelvis and hips Pin joints at knees
right femur reference frame
world
pelvis reference frame
left femur reference frame
left tibia reference frame right tibia reference frame
3 rotations
3 rotations3 rotations
1 rotation1 rotation
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 25
Why use this model ?
Application field in paleoanthropology Study of the bipedalism of fossilised hominids Australopithecus afarensis Lucy (A.L. 288-1)
pictures – courtesy of G. Berillon
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 26
Modeling the locomotion
Treatments on the motion Homogeneous reconstruction [Ménardais 03]
Orientation of the locomotion Identification of the cycles
Definition of the movement of the articular centers Computed from real landmarks Accurate positions of articular
centers and virtual points1 12
2
33
44
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 27
Modeling the locomotion
A parametrical representation of the locomotion: the poulaine
Modeled by a cubic curve using 4 characteristic points of the cycle
1
23
4
Definition: the Cartesian displacement of the ankle in the root reference frame
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 28
Method of computation
The principle of dimensional interpolation in the database Definition of the step size on x Definition of the step shift on y Definition of the rest posture on z
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 29
Post-treatments
Adding the temporal dimension Use of an average profile of speed, normalised by the
time cycle and distance on the ground Representation of the profile by a polynomial function Integrating the function, computing the curvilinear x-
coordinate and the parameters of the cubic curves Synchronisation of the left and right poulaines
By minimisation of vertical differences By minimisation of ground sliding
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 30
Post-treatments
Computation of the postures by an IK solver
Proposition of secondary tasks [Nicolas et al. 04]
(C1) Maximal distance from joint limits (C2) Minimisation of the kinematical energy of rotation (C3) Search of the closest posture to the rest posture
Evaluation of these tasks by 3 criteria The total Jerk, third derivate of the angles The difference between the final and the initial posture The internal work
J X I J J z
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 31
Post-treatments
Preparation of the animation Construction of the foot and the ankle angle
Feet lenghts from anthropometrical tables [De Leva 96]
Trajectories of ankles computed by corrections of the ground penetrations
To go to the global motion Global displacement minimising the sliding
Upper body movement Adapted to the morphology and synchronised with the
real motion
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 32
Results of the adaptation
Validation of the interpolation
x axis x axis z axis Average
RMS (cm) 2.74 1.22 1.24 1.73
S.D. (cm) 1.18 1.12 0.76 0.82
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 33
Results of the adaptation
Validation of the adaptation Comparison between real angular trajectories and
adapted trajectories of 7 subjects in the database
Pelv. incl. Pelv. obliq. Pelv. rot. int/ext Hip flex/ext
Average (rad) 0.03 0.01 0.01 0.05
S.D. (rad) 0.03 0.01 0.01 0.03
Hip abd/add Hip rot. int/ext Knee flex/ext
Average (rad) 0.04 0.03 0.02
S.D. (rad) 0.04 0.01 0.01
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 34
Results of the adaptation
Simulations
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 35
Partial summary
The method computes a plausible locomotion from biomechanical knowledge and rules [Pronost et al. 05] Controled by limbs sizes, bones configuration, physical parameters
of the limbs, joints types, footprints, articular limits and the style of motion
Applied to paleoanthropology [Pronost et al. 06]
Future work Combining the method with a real time adaptation to the
environment To drive the extrapolation by physical properties A global resolution of the IK to reduce discontinuity of pelvis angles Increase the size and the diversity of the database
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 36
Outline
Related works
Overview and motivations
Analysis / synthesis loop Kinematical adaptation
Evaluation of the dynamics
Forward dynamics synthesis
Conclusion and future works
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 37
Evaluation of the dynamics
Analysis of the dynamics
resulting forces
Adaptation algorithm
adapted motion
Database of motions
Synthesis by forward dynamics
synthetised motion
Database of motions
Synthesis by forward dynamics
synthetised motion
Adaptation algorithm
adapted motion
Mechanical model
Adapted motion
Scaled anthropometrical
table
Biomechanical model
Resulting forces and torques
Analysis of the
dynamics
Mapping
dimensional model
angle-based motion
Support phases recognition
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 38
Modeling the human
Creation of a biomechanical model Description of Denavit-Hartenberg
[Hartenberg and Denavit 55] Parameters of rotation:
user Parameters of translation:
auto Gender and nature of limbs
Gender: user Nature: auto Using anthropometrical tables
[deLeva 96] and regression laws [Vaughan et al. 99]
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 39
Modeling the motion
The mapping issue An iterative method on kinematical
chains from the root joint to the effectors
Using a sequencing of the articular systems
Treatment according to the number of degrees of freedom
1dof => pin joint, minimisation of the error 3 dof => spherical joint, an infinity of solutions
with constraints => minimisation of the future error without constraints => minimal rotation
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 40
Method of computation
In order to solve the inverse dynamics issue, we have to know the external forces applied to the system, for locomotion: the gravity
constant value for any motion the aerodynamical forces
supposed negligible the ground reaction forces
When are they applied ? Support phase recognition
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 41
Support phase recognition
Evaluation of 4 methods of ground contacts recognition hand-labeled, method of reference, accurate at the
frequency of the motion capture system speed, evaluation of a speed threshold for the effectors height, evaluation of a height threshold for the effectors configuration, particular configurations of the effectors
By four criteria the number of failures the average error its S.D. the normalised S.D. of the thresholds
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 42
Support phase recognition
Results with 12 x 2 (left/right) x 2 (flex/ext) = 48 contacts
Results of the thresholds estimation with heels and toes effectors
Our algorithm chooses the best method according to the configuration of the effectors and the evaluation of the criteria
Criteria/rank 1 2 3
Number of failure (0) speed (0) config (16) Height
Average error (2.3) speed (5.6) height (9.7) config
S.D. (1.6) speed (2.1) config (2.4) height
S.D. norm (-) config (0.41) height (0.5) speed
Heel strike Toe off
Height (%) 13.0 13.37
Speed (m/s) 0.73 0.39
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 43
Application of Newton’s law
Application of the FBD principle Free Body Diagram on each segment Study of forces and torques applied to the
limbs
Application of Newton’s second law of motion
on limbs s
SS
s
CGCGs
CGss
ITorques
amForces
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 44
Resolution of the equations
The translation form Single support, from the free foot to
the support foot Double support, global resolution
No support, independent resolution
The rotation form Iterative resolution of the equation:
CGO1 FR1CGO2 FR2
I CGÝ CG
s Rs T. I CGs
. Rs . Ý CGs
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 45
Validation of the resolution
Forces (in N) at left toe and torques (in N.m) at left knee of 6 adapted locomotions
For
ces
(N)
Tor
ques
(N
.m)
cycle % cycle % cycle %
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 46
Validation of the resolution
Comparison between 3 real ground reaction forces (black plots) and analysed forces (blue plot) from characters with similar biomechanical properties
GR
F (
N)
support phase support phase support phase
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 47
Validation of the resolution
Ground reaction forces of different styles of real locomotions
run
jump
walk
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 48
Influence of the retargeting
The global scale Most used parameter Large influence on the dynamics of the motion Linear relation (c.c. = 0.87) between the scale and the
relative values of the GRF Experimental validation between [0.7 , 1.2] scales
GR
F (
N)
cycle % global scale
rela
tive
GR
F
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 49
Influence of the retargeting
The femur/tibia ratio To evaluate errors on articular centers (relative length of
limbs) Experimental validation between [0.8 , 1.2] ratios The GRF are not compensated by relative lenghts of the
limbs
RM
S e
rror
cycle % femur/tibia ratio
GR
F (
N)
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 50
Influence of the retargeting
The structure of the skeleton Models with 33 and 21 dof (pin joints at knees, ankles and
elbows) Kinematical influence: 1.4 cm per limbs Dynamical influence: mostly on fore-aft acceleration Here, corresponds to 2.5 kg reduction (4.5 % of the mass)
GR
F (
N)
cycle % cycle %
RM
S e
rror
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 51
Influence of the kinematical interpolation
The step size To study the kinematical correction of support phases Results are in agreement with the interpolation: stage of
valid corrections (database of motions) To improve this database with more motions, with more step
sizes
GR
F (
N)
cycle % step size factor
RM
S e
rror
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 52
Influence of the kinematical interpolation
The motion style Defined by the rest posture, i.e. the erect percentile More bent style: nonsignificant errors More erect style: increase of the error Large steps can not be done with a hight erect posture
GR
F (
N)
cycle % erect percentile factor
RM
S e
rror
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 53
Influence of the kinematical interpolation
The character velocity Used for generating new motions Velocity , error but physics OK Velocity , double hump amplitude Need to change the style of locomotion (ex: run)
GR
F (
N)
cycle % velocity factor
RM
S e
rror
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 54
Partial summary
Method of evaluation of the dynamics influences of a locomotion editing method [Pronost and Dumont 06 a] The analysis is automatic, generic and independent [Pronost and
Dumont 06 b]
Applied on a retargeting approach and a kinematical interpolation in a database
The editing method is valid on the experimental range of validation
Future work To validate the analysis using more experimental data To overcome standard limitation of inverse dynamics issue, such as
complex articular systems and muscular activation To use the dynamics-based analysis to correct motions
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 55
Outline
Related works
Overview and motivations
Analysis / synthesis loop Kinematical adaptation
Evaluation of the dynamics
Forward dynamics synthesis
Conclusion and future work
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 56
Forward dynamics synthesis
Analysis of the dynamics
resulting forces
Adaptation algorithm
adapted motion
Database of motions
Synthesis by forward dynamics
synthetised motion
Database of motions
Adaptation algorithm
adapted motion
Analysis of the dynamics
resulting forces
Symbolical equations of
motion
Resolution of the equations
Synthesised motion
Synthesis by
forward
dynamics
Dof variations
Initial state External forces Motor torques
Mechanical system
Velocities and
accelerations of the dof
Ground reaction forces
Bodies: masses, inertias, matrix Joints: type, mechanical parameters
Dof values
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 57
Modeling
Of the human Representation of the rigid bodies
masses, inertias and rotation matrix Representation of the mechanical joints
type: free (6 dof), spherical (3 dof), pin (1 dof) mechanical parameters
spring, damper, and limits
Of the motion Values of the degrees of freedom of the mechanical
system
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 58
Normalisation of the forces and torques Principle
Preliminary study on 5 motions
Method of computation
MotionInverse
dynamics analysis
MotionMorphology (mass, inertia)Normalised forces & torquesMotion ’ Forward
dynamics synthesis
Morphology ’
{
Subject 1 Subject 2
Normal N1,1,N1,2 N2
Bent F1 F2
N1,1 N1,2 F1 N2 F2
RMS(1) 0 0.234 0.621 0.512 1.001
M.E. 0 0.026 0.068 0.056 0.109
M.STDP (x10-3) 0 8.7 13.9 3.5 23.0
C.C. 1 0.973 0.681 0.980 0.399
C.ACP 1 0.995 0.322 0.332 0.328
Deriv (x10-4) 0 12.0 23.0 6.4 42.0
N1,1 N1,2 F1 N2 F2
RMS(1) 0 0.150 0.426 0.141 0.946
M.E. 0 0.025 0.071 0.026 0.148
M.STDP (x10-2) 0 22.6 55.6 22.9 129.3
C.C. 1 0.938 0.826 0.954 0.702
C.ACP 1 0.945 0.848 0.962 0.802
Deriv (x10-3) 0 36.5 74.1 37.3 162.2
Differences and similarities of root positions Differences and similarities of normalised GRF
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 59
Preliminary results
The forward dynamics resolution using the NMECAM library [Arnaldi 89, Dumont 90]
library defining a symbolic solver of motion equations Results on a virtual human without external forces
and with independent limbs
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 60
Partial summary
The whole of the principles are not yet implemented Apprehension of the phenomena of the forward dynamics
issue Usefull approach of normalisation in many fields such as
kinematics and kinetics synthesis To make choices according to physical properties of the
synthetised motion Future work
Simulation of a complete chain of a human with external forces
To organise a database including physical properties such as normalised profiles of forces and torques
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 61
Outline
Related works
Overview and motivations
Analysis / synthesis loop Kinematical adaptation
Evaluation of the dynamics
Forward dynamics synthesis
Conclusion and future work
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 62
Conclusion
To understand and to simulate human motions Analysis and synthesis approaches Many applicatives fields
animation, biomechanics, mechanics, anthropology Kinematical adaptation of captured motions preserving the
physical credibility of the synthetised motions Proposition of methods and algorithms combining
kinematical and dynamical approaches Adapted to the morphology and the locomotion Normalisation of the data, of the morphological structures
and the forces and torques Use of principles and data from biomechanics
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 63
Limitations and future work
On the methods Study of other motions with external forces To increase the size and the diversity of the database
and the experimental data for the interpolation and the physical validation
To use the analysis to drive the kinematical synthesis thanks to physical simulations
To do a unique method with the proposed approaches
On the applications Motion editing, biomechanics, anthropology But also on the modeling and the use of data on virtual
humans
Nicolas Pronost – Definition and realisation of modeling methods and motion computation algorithms for virtual humans 64
Thank you for your attention
Definition and realisation of modeling methods and motion computation algorithms for virtual humans
Nicolas PronostAdvisor : Bruno Arnaldi
Co-advisor : Georges Dumont
Team : IRISA - SIAMES