Editing The Matrix (section)

=== Visual effects ===
[[File:The Matrix Bullet Time Effect.ogv|thumb|The "[[bullet time]]" effect was created for the film. A scene would be computer-modeled to decide the positioning of the physical cameras. The actor then provided their performance in a [[chroma key]] setup, while the cameras were fired in rapid succession, with fractions of a second delay between each shot. The result was combined with CGI backgrounds to create the final effect at (0:33).|alt=Video sample of the film]]

{{blockquote|As for artistic inspiration for bullet time, I would credit [[Otomo Katsuhiro]], who co-wrote and directed ''[[Akira (1988 film)|Akira]]'', which definitely blew me away, along with director [[Michel Gondry]]. His music videos experimented with a different type of technique called view-morphing and it was just part of the beginning of uncovering the creative approaches toward using still cameras for special effects. Our technique was significantly different because we built it to move around objects that were themselves in motion, and we were also able to create slow-motion events that 'virtual cameras' could move around—rather than the static action in Gondry's music videos with limited camera moves.|[[John Gaeta]]<ref name="gaeta-empire">{{Cite journal |date=February 2006 |title=200 Things That Rocked Our World: Bullet Time |journal=[[Empire (magazine)|Empire]] |issue=200 |page=136}}</ref>}}

The film is known for popularizing a [[visual effect]]<ref name="Lane City of God"/> known as "[[bullet time]]", which allows a [[shot (filmmaking)|shot]] to progress in [[slow motion]] while the camera appears to move through the scene at normal speed.<ref name="guardian-sfx">{{Cite news |last=Green |first=Dave |date=June 5, 1999 |title=Better than SFX |work=Guardian.co.uk |publisher=[[Guardian Media Group]] |location=London |url=https://www.theguardian.com/film/1999/jun/05/features2 |access-date=December 18, 2009 |archive-date=December 23, 2019 |archive-url=https://web.archive.org/web/20191223102908/https://www.theguardian.com/film/1999/jun/05/features2 |url-status=live }}</ref><ref>{{Cite web |last=Shields |first=Meg |date=2021-12-23 |title=How They Shot the "Bullet-Time" Effect in 'The Matrix' |url=https://filmschoolrejects.com/the-matrix-bullet-time/ |access-date=2023-09-15 |website=Film School Rejects |language=en-US}}</ref> Bullet time has been described as "a visual analogy for privileged moments of consciousness within the Matrix",<ref>{{Cite book |last=Clover |first=Joshua |url=https://archive.org/details/matrix0000clov |title=The Matrix |publisher=[[British Film Institute|BFI Publishing]] |year=2004 |isbn=978-1-84457-045-4 |location=London |page=[https://archive.org/details/matrix0000clov/page/35 35] |url-access=registration}}</ref> and throughout the film, the effect is used to illustrate characters' exertion of control over time and space.<ref>{{Cite book |last=Wood |first=Aylish |title=Digital Encounters |date=April 17, 2007 |publisher=Routledge |isbn=978-0-415-41066-3 |edition=New}}</ref> The Wachowskis first imagined an action sequence that slowed time while the camera pivoted rapidly around the subjects, and proposed the effect in their screenplay for the film. When [[John Gaeta]] read the script, he pleaded with an effects producer at [[Manex Visual Effects|Mass.Illusion]] to let him work on the project, and created a prototype that led to him becoming the film's visual effects supervisor.<ref name="Wired VFX">{{Cite magazine |last=Silberman, Steve |date=May 2003 |title=Matrix2 |url=https://www.wired.com/2003/05/matrix2/ |magazine=[[Wired (magazine)|Wired]] |access-date=December 25, 2012 |archive-date=March 4, 2020 |archive-url=https://web.archive.org/web/20200304014830/https://www.wired.com/2003/05/matrix2/ |url-status=live }}</ref><ref>{{Cite web |date=2019-03-31 |title=Bullet Time before Bullet Time - beforesandafters.com |url=https://beforesandafters.com/2019/04/01/bullet-time-before-bullet-time/ |access-date=2023-09-15 |website=befores & afters |language=en-US}}</ref>

The method used for creating these effects involved a technically expanded version of an old art photography technique known as time-slice photography, in which an array of cameras are placed around an object and triggered simultaneously. Each camera captures a still picture, contributing one frame to the video sequence, which creates the effect of "virtual camera movement"; the illusion of a viewpoint moving around an object that appears frozen in time.<ref name="guardian-sfx"/>

The bullet time effect is similar but slightly more complicated, incorporating temporal motion so that rather than appearing totally frozen, the scene progresses in slow and variable motion.<ref name="gaeta-empire"/><ref name="Wired VFX"/> The cameras' positions and exposures were [[Previsualization|previsualized]] using a 3D simulation. Instead of firing the cameras simultaneously, the visual effect team fired the cameras fractions of a second after each other, so that each camera could capture the action as it progressed, creating a super slow-motion effect.<ref name="guardian-sfx"/> When the frames were put together, the resulting slow-motion effects reached a [[frame frequency]] of 12,000 per second, as opposed to the normal 24 frames per second of film.<ref name="Influence Screened"/> Standard movie cameras were placed at the ends of the array to pick up the normal speed action before and after. Because the cameras circle the subject almost completely in most of the sequences, computer technology was used to edit out the cameras that appeared in the background on the other side.<ref name="guardian-sfx"/> To create backgrounds, Gaeta hired George Borshukov, who created 3D models based on the geometry of buildings and used the photographs of the buildings themselves as texture.{{citation needed|date=February 2024}}

The photo-realistic surroundings generated by this method were incorporated into the bullet time scene,<ref name="Wired VFX"/> and algorithms based on [[optical flow]] were used to interpolate between the still images to produce a fluent dynamic motion;<ref>{{cite web |last=Seymour |first=Mike |title=Art of Optical Flow |url=https://www.fxguide.com/featured/art_of_optical_flow/ |access-date=March 25, 2019 |website=fxguide |date=February 28, 2006 |archive-date=March 25, 2019 |archive-url=https://web.archive.org/web/20190325005829/https://www.fxguide.com/featured/art_of_optical_flow/ |url-status=live }}</ref><ref>{{cite web |last=Buckley |first=Robert |title=Film Essay on The "Bullet Time" Scene In "The Matrix" |url=http://scis.nova.edu/~rbuckley/Film%20Essay.pdf |url-status=dead |archive-url=https://web.archive.org/web/20130515001756/http://scis.nova.edu/~rbuckley/Film%20Essay.pdf |archive-date=May 15, 2013 |access-date=December 27, 2012 |publisher=Graduate School of Computer and Information Sciences, Nova Southeastern University }}</ref> the computer-generated "lead in" and "lead out" slides were filled in between frames in sequence to get an illusion of orbiting the scene.<ref>{{cite web |last=Tiwari |first=Abhishek |title=Bullet Time Technique |url=http://www.sbc.ac.in/voice/bullet.htm |url-status=dead |archive-url=https://web.archive.org/web/20120915002004/http://www.sbc.ac.in/voice/bullet.htm |archive-date=September 15, 2012 |access-date=December 27, 2012 |website=Voice |publisher=School of Broadcasting and Communication |location=Mumbai }}</ref> Manex Visual Effects used a [[cluster (computing)|cluster]] farm running the [[Unix-like]] [[operating system]] [[FreeBSD]] to render many of the film's visual effects.<ref>{{cite web |date=January 23, 2008 |title=Comment about the use of FreeBSD (5:50) |url=https://www.youtube.com/watch?v=bAsYz5pVwyc#t=5m45s |archive-url=https://ghostarchive.org/varchive/youtube/20211211/bAsYz5pVwyc| archive-date=December 11, 2021 |url-status=live|access-date=January 29, 2012 |website=YouTube}}{{cbignore}}</ref><ref>{{cite web |date=April 22, 1999 |title=FreeBSD Used to Generate Spectacular Special Effects |url=http://www.freebsd.org/news/press-rel-1.html |access-date=July 19, 2012 |archive-date=August 18, 2012 |archive-url=https://web.archive.org/web/20120818022437/http://www.freebsd.org/news/press-rel-1.html |url-status=live }}</ref>

Manex also handled creature effects, such as Sentinels and machines in real world scenes; [[Animal Logic]] created the code hallway and the exploding Agent at the end of the film. DFilm managed scenes that required heavy use of digital compositing, such as Neo's jump off a skyscraper and the helicopter crash into a building. The ripple effect in the latter scene was created digitally, but the shot also included practical elements, and months of extensive research were needed to find the correct kind of glass and explosives to use. The scene was shot by colliding a quarter-scale helicopter mock-up into a glass wall wired to concentric rings of explosives; the explosives were then triggered in sequence from the center outward, to create a wave of exploding glass.<ref name="Post-production">{{Cite AV media |title=[[The Matrix Revisited]] |date=November 20, 2001 |last=Oreck, Josh (Director); Wachowski, Larry; Matthies, Eric (Producers) |publisher=[[Warner Bros. Pictures]] |place=United States |section=Post-production |medium=DVD}}</ref>

The [[Photogrammetry|photogrammetric]] and image-based [[computer-generated imagery|computer-generated]] background approaches in ''The Matrix''{{'}}s bullet time evolved into innovations unveiled in the sequels ''[[The Matrix Reloaded]]'' and ''[[The Matrix Revolutions]]''. The method of using real photographs of buildings as texture for 3D models eventually led the visual effect team to digitize all data, such as scenes, characters' motions and expressions. It also led to the development of "Universal Capture", a process which samples and stores facial details and expressions at high resolution. With these highly detailed collected data, the team were able to create virtual cinematography in which characters, locations and events can all be created digitally and viewed through virtual cameras, eliminating the restrictions of real cameras.<ref name="Wired VFX"/>