Course Review

Computer Animation and Visualisation

Taku Komura

Topics● Color mapping● Keyframe animation, Inverse Kinematics● Motion Capture● Motion Blending● Facial capture and transfer● Physically-based character animation

– Forward dynamics

– Inverse dynamics

● Crowd animation– Flocking

– Continuum crowds

– RVO

●

Topics (2)

● Fluid Simulation– SPH

● Volume rendering ● Contouring ● Flow visualisation

– Glyphs, streamline, streakline

● 3D Mesh processing● Shape comparison, retrieval● Information Visualisation

https://www.youtube.com/watch?v=iN9WP2VZwWQ&hd=1

Topics● Color mapping● Keyframe animation, Inverse Kinematics● Motion Capture● Motion Blending● Facial capture and transfer● Physically-based character animation

– Forward dynamics

– Inverse dynamics

● Crowd animation– Flocking

– Continuum crowds

– RVO

.....

●

Character Animation

● Motion Capture●

Pseudo-inverse method

Iteratively updating the generalized coordinates so that the position constraints are satisfied

e: end effector position

g: target location

while ( Δe is too far from g) {

compute the Jacobian matrix J

compute the pseudoinverse of the Jacobian matrix J

compute change in joint DOFs: Δq=J Δe

apply the change to DOFs, move a small step of q=q+ Δq

}

Δe =JΔq

+

+

http://thewanderingtech.50webs.com/Flash/IK%20Comparison%20Application/IKCompare.html

Physically-based animation

• Using Newton's laws of dynamics to simulate various phenomena

– Drop objects in the scene, and let them collide and see what happens

– Blowing hair by a dryer

– Add force to the bodies and torque to the joints and simulate the movements of human figures

Forward / Inverse Dynamics

• Forward dynamics: Adding force and simulate what happens

Then, update the velocity and position by the computed acceleration

INPUTOUTPUT

Forward / Inverse Dynamics

• Inverse dynamics: Given a motion, calculate the force / torque

INPUT

OUTPUT

Forward Dynamics for Human Animation

– Passive motions

• Falling down (No force or torque, rag-doll)• pushed and stepping back

– Voluntary motions → Walking, Running 　

Flow Visualisation

● Glyphs, streamlines, streaklines

Processing 3D Surface Data

● 1) Capture the data (by stereo vision, range scanner)● 2) Registration (if the data was captured by multiple

attempts)● 3) Adding the topology : converting to mesh data● 4) Smoothing● 5) Decimation● 6) Remeshing

Metaballs (implicit surface)

Mesh Shape Editing

● Laplacian mesh editing● As rigid as possible shape interpolation● Barycentric coordinates

Shape Matching and Retrieval

● Local Features– Curvature

● Global Features– Reeb graphs, medial axis

● Both – Heat Kernel Signature

–

Information Visualisation

● Parallel coordinates – multivariate data● Graph visualisation● Literature visualisation

Thank you !!

● Good luck