Check out this montage too https://www.youtube.com/watch?v=soUo0X8aXuA

1. Motion Capture
Technology

2. Overview:
 Definition of Motion Capture
 History of Mocap
 Rotoscoping
 Types of Motion Capture
 Mechanical
 Optical
 Electromagnetic
 Marker Placement
 Production Pipeline
 Applications of MoCap
 Examples

3. What is Motion Capture?
Motion capture is the process of recording human
movement through specialised camera’s, and mapping
them onto a character model.
 Also known as “Mo-Cap, Real-Time Animation” or
“Performance Capture”

4. The Motion Capture began in late 1800’s when Etienne
Jules Marey and Eadweard Muybridge performed
motion studies on various animals and humans
History of Motion Capture
Etienne Jules Marey’s
Motion Capture Suit
Eadweard Muybridge
•Historically, Motion
Capture in animated
movies was created
using the extension of
"ROTOSCOPING"
technique.

5. Eadweard Muybridge (1830-1904)
 “Father of the motion picture”
 several cameras – successive
pictures
 photographs of human and animal
motion
 zoopraxiscope (zoogyroscope,
zoetrope) – a device for playing
still images in sequence

6. Rotoscope
Allow animators to trace cartoon character over
photographed frames of live performances
• invented by Max Fleischer in 1915

7. Rotoscope
Allow animators to trace cartoon character over
photographed frames of live performances
• invented by Max Fleischer in 1915
• 2D manual motion capture
A horse animated by rotoscoping
from Muybridge’s photos

8. Rotoscoping
“rotoscoping can be thought of as a primitive form or precursor
to motion capture, where the motion is ‘captured’ painstakingly
by hand.” - Sturman

9. “3D Rotoscoping”: measuring 3D positions, orientations,
velocities or accelerations automatically
Current motion capture systems
• Electromagnetic
• Electromechanical
• Fiber optic
• Optical
Current Motion Capture
Technologies

10.  This approach has a
central magnet with
several receivers attached
to the actor’s body. The
receivers capture and
record the actors
movements and save
them to the computer.
This motion capture
method can be hindered
by nearby metal objects if
they are large enough and
depending on the power
of magnets being used. A suit with magnetic sensors

11. Electromagnetic systems
 Electromagnetic sensors
placed on joints of moving
object
 Measures orientation and
position of sensor relative to
electromagnetic field
generated by transmitter
 No occlusion, multiple subjects
 Electromagnetic interference,
small volume

12. Pros
• measure 3D positions and orientations
• no occlusion problems
• can capture multiple subjects simultaneously
Cons
• magnetic perturbations (metal)
• small capture volume
• cannot capture deformation (facial expression)
• hard to capture small bone movement (finger movement)
• not as accurate as optical MoCap systems
Electromagnetic MoCap

13.  Electromechanical Motion
Capture uses Potentiometers
on the aforementioned plastic
exoskeleton that an actor must
“wear”, and then act out his or
her movements. This is very
accurate and transmits real-
time data at a far greater range
than any other technology.
A gypsy3 prosthetic suite

14. Pros
• Measure 3D orientations
• No occlusion problems
• Can capture multiple subjects simultaneously
• Large capture volume
• Portable and outdoors capture (e.g. skiing)
Cons
• Getting 3D position info is not easy
• Cannot capture facial expression
• Hard to capture small bone movement (finger motion)
• Not as accurate as optical MoCap system
Electromechanical Mocap

15. • Reflective markers
• Multiple cameras
digitize different views
of performance
• High speed capture
• High data accuracy
• Occlusion
• Position sensitive
cameras
• Limited volume

17. Optical capture
 advantages
 freedom of movement
 high quality capture
 Can Capture Facial Expression
 high throughput
 fast sampling (200 fps at a high resolution)
 can capture fast motions
 can have a large capture space
 can capture many markers
 disadvantages
 occlusion, markers are can be hidden from the camera
 additional performers will increase occlusion
 may be able to add redundant cameras
 marker crossover, which marker are you looking at?
 cost $$$
 extensive post processing (the marker’s have to be located and identified)

19. Major Optical Players
Motion Analysis
 Films
 Lord of the Rings
 King Kong
 Matrix
 Final Fantasy
 Games
 NBA Live 2004
 Grand Theft Auto III
 Mortal Kombat 4 (Midway)
Films
 Polar Express
 Harry Potter and the
Prisoner of Azkaban
 The Hulk
 Spider Man
 Games
 All-Star Baseball 2002
 Buffy the Vampire Slayer
 Everquest II
 NHL 2K3 (Mocap by
Red Eye Studio)

20. Production Pipeline
Sensor
Calibration
Subject
Calibration
Record
Movements
Compute the position
and orientation of
camera/transmitter
Place markers on body,
compute skeleton
structure(lengths of
links)
Marker positions (and
orientations) varying over
time
Marker Data
Cleanup
Convert to Joint
Angles
Occlusion and
correspondence problemsOcclusion and
correspondence problems
Mapping to
characters
Direct Mapping or
retargetting

21. Process of Motion
Capture (1)
• Recording area is
constructed (often blue
screen or green screen
area)
• Cameras are set up to
record the actors
movement
• Cameras map 360 degree
image of the person

22. {
Process of Motion Capture
(2)
• Suit fitted with nodes
• Camera follows nodes
• Triangulates
information
• DATA is recorded and
ready to be
manipulated

23. {
Process of Motion Capture
(3)
• DATA given to an
animator
• Manipulation of digital
skeleton
• Helps character
creation

24. Applications
 Entertainment
 Medicine
 Arts / Education
 Science / Engineering

25. Entertainment: Live Action Films
 Computer generated characters in live action
films (e.g. Battle Droids and many others in Star
Wars Prequels, Gollum in The Lord of the Rings,
King Kong in King Kong , Davy Jones in Pirates
of Caribbean)

26. Entertainment: 3D computer animations
 Characters in computer animated files (e.g. Polar
Express, Monster House)
Kochadaiyaan (India's first photorealistic performance
capture film) //After all he is Rajnikanth!!

27. Entertainment: Video
Games
 Video games by Electronic Arts, Gremlin, id,
RARE, Square, Konami, Namco, and others, (e.g.
Enemy Territory, Devil May Cry,FIFA)

28. Medicine
 Medicine (e.g., gait analysis, rehabilitation)
 Sports medicine (e.g. injury prevention,
performance analyses, performance
enhancement)
Gait Analysis Service

29. Science / Engineering
 Engineering (e.g., Biped robot developments)
 Ergonomic product design
 Military (e.g., field exercises, virtual instructors,
and role-playing games)

30. Any Questions?