Motion capture involves sensing and recording human or object motion as 3D data. There are several motion capture methods, including prosthetic, acoustic, electromagnetic, optical fiber, and optical. Optical motion capture uses reflective markers and high-speed cameras to capture high accuracy marker data. The motion data goes through processing like cleanup and mapping to digital characters. Motion capture is used extensively in movies for animating realistic characters and scenes but has limitations like expense and inability to add more expression than what is captured. Future improvements may include markerless motion capture and cheaper systems.

1. Motion Capture
Technology
by
T.Aswanth
Id no-12006270
No-49(sec-D)

2. What is Motion Capture?
Motion capture (mocap) is sampling
and recording motion of humans,
animals and inanimate objects as 3d
data for analysis, playback and
remapping.

3. Motion Capture of an object involves sensing,
digitizing, and recording that object in motion
• Whole body
• Hands ,Limbs
• Face
• One way of acting out an animation

4. History of Motion Capture
• Eadweard Maybridge (1830-1904)
• Etienne-Jules Marey (1830-1904)
• Harold Edgerton (1903-1990)
Marey and Maybridge conducted human and animal motion studies by
shooting multiple photographs of moving subjects over a short period of time.
Harold Edgerton was the inventor of flash photography.

5. There are primarily five methods in motion capture.
They are :
 Prosthetic (or Electromechanical)
 Acoustic
 Electromagnetic
 Optical fiber
 Optical

6.  Prosthetic Motion Capture uses Potentiometers on the
plastic exoskeleton that an actor must “wear”, and
then act out their movements. This is very accurate and
transmits real-time data at a far greater range than any
other technology.

7.  Acoustic Motion Capture uses audio transmitters on the actor’s
body and Set of microphones receive sound waves.
 Other sounds in frequency range can disrupt capture
 Accuracy not as high as other systems
 Limited Rage and Limited number of sensors

8.  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.

9.  Fiber-optic sensor
 Bend and twist sensors measure transmitted light
 No occlusion
 Multiple subjects
 Portable
 Adjustment to individual proportions is limited
 Less accurate data

10.  Reflective markers
 High speed capture
 High data accuracy
 Multiple Cameras that digitize different
views of performance

11. Production Process:
Sensor
Calibration
Subject
Calibration
Record
Movements
Marker Data
Cleanup
Convert to
Joint Angles
Mapping to
characters

12. Post Processing:
 Motion Editing:
Cut, Copy, Paste
 Motion Warping:
Speed up or Slow Down
Rotate, Scale or Translate
 Motion Signal Processing:
Smoother Motions

13. Limitations of MOCAP
o Subject to data inaccuracy
o Expensive
o Only realistic motion captured
o Cartoony Animations not possible
o WYSIWYG (what you see is what you get)
o Can’t add more expression
o Continally need to recapture motion

14. The Future of MOCAP
 Markerless MOCAP
 Cheaper MOCAP
 MOCAP as Input to Large Displays

15. Input Device Frame Rate
Range
(hz)
Position
Accuracy
Orientation
Accuracy
Latency &
range
Maximum
Points
tracked
Use in Movies Cost Range
(USD)
Polhemus
(Magnetic)
60-240 .03in RMS static
0.00015in at
12in range
.15° RMS static
0.0012° at 12in
range
3.5ms
5 ft
16 Woody and Hamm
in Toy Story, The
Chandelier in
Beauty and the
Beast
$8’495 -
$21’925
Vicon (Optical) 166-10’000 1/117’600in or
0.02 of a Pixel
up to 4MP
No camera
limit
500 Sony, Nintendo,
Microsoft, Boeing,
$89’170 -
$209’920
Ascension
ReActor 2
(Magnetic)
100 0.08cm RMS at
1.52m range
0.5° RMS at
1.52m range
4.11m x
4.11m area
30 $99,410 -
$102’315
Gypsy
(Mechanical)
wireless possible
12-120 No Absolute
position
1° 200m 42 $20’000 -
$27’000
Stats:

16. Feature Films:
• Avatar
• Curious Case of BenjaminButton
• Pirates of the Carribean
• The Incredible Hulk
• Lord of the Rings
• Polar Express
• Matrix
• Kocchadaiyan
• Dawn of the planet of the apes

18. Conclusion:
Motion capture (MOCAP) is an effective 3D animation
tool for realistically capturing human motion

19. Any Questions ?????

20. Thank you!!!!