Motion Capture in 3D Animation Edward Tse

Motion Capture as a Tool Motion capture (MOCAP) is an effective 3D animation tool for realistically capturing human motion Motion capture (MOCAP) is an effective 3D animation tool for realistically capturing human motion

Outline Rotoscoping Rotoscoping The MOCAP Pipeline The MOCAP Pipeline Limitations of MOCAP Limitations of MOCAP The Future of MOCAP The Future of MOCAP By the Power of Appendix B!!

Rotoscoping Captured Video Captured Video History Johnston, et al., 1995

Rotoscoping History Tracing Tracing Johnston, et al., 1995

Rotoscoping Post Processing Post Processing Johnston, et al., 1995

The MOCAP Pipeline Calibration Calibration Capture Capture 3D Position Reconstruction 3D Position Reconstruction Fitting to the Skeleton Fitting to the Skeleton Post Processing Post Processing

Capture Optical Magnetic Mechanical Costa-Sousa, M., 2004 Infra Red LEDs Magnetic Transmitter Potentiometers

Calibration Image Space World Space (X,Y)(X,Y,Z) (X,Y)(X,Y,Z) (X,Y)(X,Y,Z)

3D Position Reconstruction (Utopia)

3D Position Reconstruction (Reality)

Multiple Markers For small number of markers: Size For small number of markers: Size Occlusions are a problem Occlusions are a problem Multiple Hypothesis Tracking Multiple Hypothesis Tracking Ringer, et al., 2002 C1 C2

Multiple Markers Mechanical Optical Hybrids Mechanical Optical Hybrids

Fitting to the Skeleton Utopian approach Utopian approach –10 – 20% length changes Markers on both sides Markers on both sides Joint Displacement Joint Displacement Use Rotation Angles Only Use Rotation Angles Only

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

Limitations of MOCAP Subject to data inaccuracy Subject to data inaccuracy Expensive Expensive Device Cost for Body capture (USD) Mechanical $20’000 – $30’000 Electromagnetic $100’000 – $120’000 Optical $90’000 – $210’000

Limitations of MOCAP Only realistic motion captured Only realistic motion captured –Cartoony Animations not possible WYSIWYG (what you see is what you get) WYSIWYG (what you see is what you get) –Can’t add more expression –Continally need to recapture motion Robertson, B., 2001

The Future of MOCAP Markerless MOCAP Markerless MOCAP Cheaper MOCAP Cheaper MOCAP MOCAP as Input to Large Displays MOCAP as Input to Large Displays hollywoodjesus.com Ngan, S., 2004 Bregler et al., 2002

Conclusion Motion capture (MOCAP) is an effective 3D animation tool for realistically capturing human motion Motion capture (MOCAP) is an effective 3D animation tool for realistically capturing human motion Questions?

References Johnston, O., Thomas, F., (1995) The Illusion of Life: Disney Animation, Disney Editions, ISBN: Johnston, O., Thomas, F., (1995) The Illusion of Life: Disney Animation, Disney Editions, ISBN: Costa-Sousa, M. (2004) Motion Synthesis, Powerpoint Presentation Costa-Sousa, M. (2004) Motion Synthesis, Powerpoint Presentation Parent, R. (2002) Computer Animation: Algorithms and Techniques, Morgan Kaufmann Publishing Parent, R. (2002) Computer Animation: Algorithms and Techniques, Morgan Kaufmann Publishing Ringer, M., Lasenby, J. (2002) Multiple Hypothesis Tracking for Automatic Optical Motion Capture, European Conference on Computer Vision (ECCV ’02) Ringer, M., Lasenby, J. (2002) Multiple Hypothesis Tracking for Automatic Optical Motion Capture, European Conference on Computer Vision (ECCV ’02) Robertson, B. (2001) Medieval Magic, Computer Graphics World, April Robertson, B. (2001) Medieval Magic, Computer Graphics World, April Tse, E. (2004) The Single Display Groupware Toolkit, MSc Thesis, University of Calgary, Ab, Canada Tse, E. (2004) The Single Display Groupware Toolkit, MSc Thesis, University of Calgary, Ab, Canada Bregler, C., Loeb, L., Chuang, E., Deshpande, H., (2002) Turning to the Masters: Motion Capturing Cartoons, Proceedings of ACM Siggraph 2002 pp 399 – 407. Bregler, C., Loeb, L., Chuang, E., Deshpande, H., (2002) Turning to the Masters: Motion Capturing Cartoons, Proceedings of ACM Siggraph 2002 pp 399 – 407. vicon.com, inition.co.uk, polhemus.com, wikipedia.org, animazoo.com, hollywoodjesus.com vicon.com, inition.co.uk, polhemus.com, wikipedia.org, animazoo.com, hollywoodjesus.com

Bonus Slides Stuff that’s too cool for you!

Stats Input DeviceFrame Rate Range (hz) Position Accuracy Orientation Accuracy Latency & range Maximum Points tracked Use in MoviesCost Range (USD) Polhemus (Magnetic) in RMS static in at 12in range.15° RMS static ° at 12in range 3.5ms 5 ft 16Woody and Hamm in Toy Story, The Chandelier in Beauty and the Beast $8’495 - $21’925 Vicon (Optical) ’0001/117’600in or 0.02 of a Pixel up to 4MP No camera limit 500Sony, Nintendo, Microsoft, Boeing, $89’170 - $209’920 Ascension ReActor 2 (Magnetic) cm 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 No Absolute position 1°200m42$20’000 - $27’000

θ 1 θ 2 Calibration

Outline History History Motion Capture Pipeline Motion Capture Pipeline Limitations Limitations Future Work Future Work