Editing Motion capture (section)

{{short description|Process of recording the movement of objects or people}}
{{Multiple issues|
{{original research | date= June 2013}}
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[[File:Temporal-Control-and-Hand-Movement-Efficiency-in-Skilled-Music-Performance-pone.0050901.s001.ogv|thumb|300px|Motion capture of two [[pianist]]s' right hands playing the same piece (slow-motion, no-sounds)<ref>{{Cite journal | last1 = Goebl | first1 = W. | last2 = Palmer | first2 = C. | editor1-last = Balasubramaniam | editor1-first = Ramesh | doi = 10.1371/journal.pone.0050901 | title = Temporal Control and Hand Movement Efficiency in Skilled Music Performance | journal = PLOS ONE | volume = 8 | issue = 1 | pages = e50901 | year = 2013 | pmid =  23300946| pmc =3536780 | bibcode = 2013PLoSO...850901G | doi-access = free }}</ref>]]
[[File:Two repetitions of a walking sequence of an individual recorded using a motion-capture system.gif|thumb|300px|Two repetitions of a walking sequence recorded using motion capture<ref>{{Citation |last1=Olsen | first1=NL |last2=Markussen |first2=B | last3=Raket | first3=LL| year=2018 |title=Simultaneous inference for misaligned multivariate functional data |journal= Journal of the Royal Statistical Society, Series C |volume=67 |issue=5 |pages=1147–76 |doi=10.1111/rssc.12276|arxiv=1606.03295 | s2cid=88515233 }}</ref>]]
'''Motion capture''' (sometimes referred as '''mocap''' or '''mo-cap''', for short) is the process of recording high-resolution [[motion (physics)|movement]] of objects or people into a computer system. It is used in [[Military science|military]], [[entertainment]], [[sports]], medical applications, and for validation of computer vision<ref>David Noonan, Peter Mountney, Daniel Elson, Ara Darzi and Guang-Zhong Yang. A Stereoscopic Fibroscope for Camera Motion and 3-D Depth Recovery During Minimally Invasive Surgery. In proc ICRA 2009, pp. 4463–68. http://www.sciweavers.org/external.php?u=http%3A%2F%2Fwww.doc.ic.ac.uk%2F%7Epmountne%2Fpublications%2FICRA%25202009.pdf&p=ieee</ref> and robots.<ref>Yamane, Katsu, and Jessica Hodgins. "[https://pdfs.semanticscholar.org/8de6/2ececd067c3d9e7d6f3462164a9a821d9e0a.pdf Simultaneous tracking and balancing of humanoid robots for imitating human motion capture data]." Intelligent Robots and Systems, 2009. IROS 2009. IEEE/RSJ International Conference on. IEEE, 2009.</ref>

In films, television shows and video games, motion capture refers to recording actions of [[Motion-capture acting|human actors]] and using that information to animate [[Character animation|digital character]] models in 2D or 3D [[computer animation]].<ref>NY Castings, Joe Gatt, [http://www.nycastings.com/dmxreadyv2/blogmanager/v3_blogmanager.asp?post=motioncaptureactors Motion Capture Actors: Body Movement Tells the Story] {{webarchive|url=https://web.archive.org/web/20140703113656/http://www.nycastings.com/dmxreadyv2/blogmanager/v3_blogmanager.asp?post=motioncaptureactors |date=2014-07-03 }}, Accessed June 21, 2014</ref><ref name=twsBackstage>Andrew Harris Salomon, Feb. 22, 2013, Backstage Magazine, [http://www.backstage.com/news/spotlight/growth-performance-capture-helping-gaming-actors-weather-slump/ Growth In Performance Capture Helping Gaming Actors Weather Slump], Accessed June 21, 2014, "..But developments in motion-capture technology, as well as new gaming consoles expected from Sony and Microsoft within the year, indicate that this niche continues to be a growth area for actors. And for those who have thought about breaking in, the message is clear: Get busy...."</ref><ref name=twsGuardian>Ben Child, 12 August 2011, ''The Guardian'', [https://www.theguardian.com/film/2011/aug/12/andy-serkis-motion-capture-acting Andy Serkis: why won't Oscars go ape over motion-capture acting? Star of Rise of the Planet of the Apes says performance capture is misunderstood and its actors deserve more respect], Accessed June 21, 2014</ref> When it includes face and fingers or captures subtle expressions, it is often referred to as '''performance capture'''.<ref name=twsWired>Hugh Hart, January 24, 2012, Wired magazine, [https://www.wired.com/2012/01/andy-serkis-oscars/ When will a motion capture actor win an Oscar?], Accessed June 21, 2014, "...the Academy of Motion Picture Arts and Sciences' historic reluctance to honor motion-capture performances ... Serkis, garbed in a sensor-embedded Lycra body suit, quickly mastered the then-novel art and science of performance-capture acting. ..."</ref> In many fields, motion capture is sometimes called '''motion tracking''', but in filmmaking and games, motion tracking usually refers more to [[match moving]].

In motion capture sessions, movements of one or more actors are sampled many times per second. Whereas early techniques used [[3D reconstruction from multiple images|images from multiple cameras to calculate 3D positions]],<ref>Cheung, German KM, et al. "[https://www.researchgate.net/profile/Takeo_Kanade/publication/3854315_Real_time_system_for_robust_3D_voxel_reconstruction_of_human_motions/links/02e7e51c9c14d5ba39000000/Real-time-system-for-robust-3D-voxel-reconstruction-of-human-motions.pdf A real time system for robust 3D voxel reconstruction of human motions]." Computer Vision and Pattern Recognition, 2000. Proceedings. IEEE Conference on. Vol. 2. IEEE, 2000.</ref> often the purpose of motion capture is to record only the movements of the actor, not their visual appearance. This ''animation data'' is mapped to a 3D model so that the model performs the same actions as the actor. This process may be contrasted with the older technique of [[rotoscoping]].

Camera movements can also be motion captured so that a virtual camera in the scene will pan, tilt or dolly around the stage driven by a camera operator while the actor is performing. At the same time, the motion capture system can capture the camera and props as well as the actor's performance. This allows the computer-generated characters, images and sets to have the same perspective as the video images from the camera. A computer processes the data and displays the movements of the actor, providing the desired camera positions in terms of objects in the set. Retroactively obtaining camera movement data from the captured footage is known as ''match moving'' or ''[[camera tracking]]''.

The first virtual actor animated by motion-capture was produced in 1993 by Didier Pourcel and his team at Gribouille. It involved "cloning" the body and face of French comedian Richard Bohringer, and then animating it with still-nascent motion-capture tools.