Computer-generated imagery

Computer-generated imagery (CGI) is the application of computer graphics to create or contribute to images in art, printed media, video games, films, television programs, shorts, commercials, videos, and simulators. The visual scenes may be dynamic or static and may be two-dimensional (2D), though the term "CGI" is most commonly used to refer to 3D computer graphics used for creating scenes or special effects in films and television. Additionally, the use of 2D CGI is often mistakenly referred to as "traditional animation", most often in the case when dedicated animation software such as Adobe Flash or Toon Boom is not used or the CGI is hand drawn using a tablet and mouse.

The term 'CGI animation' refers to dynamic CGI rendered as a movie. The term virtual world refers to agent-based, interactive environments. Computer graphics software is used to make computer-generated imagery for films, etc. Availability of CGI software and increased computer speeds have allowed individual artists and small companies to produce professional-grade films, games, and fine art from their home computers. This has brought about an Internet subculture with its own set of global celebrities, clichés, and technical vocabulary. The evolution of CGI led to the emergence of virtual cinematography in the 1990s where runs of the simulated camera are not constrained by the laws of physics.

Morphogenic digital art exhibition by Andy Lomas at Watermans Arts Centre, London
Morphogenetic Creations computer-generated digital art exhibition by Andy Lomas at Watermans Arts Centre, west London, in 2016.

Static images and landscapes

Not only do animated images form part of computer-generated imagery, natural looking landscapes (such as fractal landscapes) are also generated via computer algorithms. A simple way to generate fractal surfaces is to use an extension of the triangular mesh method, relying on the construction of some special case of a de Rham curve, e.g. midpoint displacement.[1] For instance, the algorithm may start with a large triangle, then recursively zoom in by dividing it into four smaller Sierpinski triangles, then interpolate the height of each point from its nearest neighbors.[1] The creation of a Brownian surface may be achieved not only by adding noise as new nodes are created but by adding additional noise at multiple levels of the mesh.[1] Thus a topographical map with varying levels of height can be created using relatively straightforward fractal algorithms. Some typical, easy-to-program fractals used in CGI are the plasma fractal and the more dramatic fault fractal.[2]

A large number of specific techniques have been researched and developed to produce highly focused computer-generated effects — e.g. the use of specific models to represent the chemical weathering of stones to model erosion and produce an "aged appearance" for a given stone-based surface.[3]

Architectural scenes

Lone House
A computer generated image featuring a house, made in Blender.

Modern architects use services from computer graphic firms to create 3-dimensional models for both customers and builders. These computer generated models can be more accurate than traditional drawings. Architectural animation (which provides animated movies of buildings, rather than interactive images) can also be used to see the possible relationship a building will have in relation to the environment and its surrounding buildings. The rendering of architectural spaces without the use of paper and pencil tools is now a widely accepted practice with a number of computer-assisted architectural design systems.[4]

Architectural modeling tools allow an architect to visualize a space and perform "walk-throughs" in an interactive manner, thus providing "interactive environments" both at the urban and building levels.[5] Specific applications in architecture not only include the specification of building structures (such as walls and windows) and walk-throughs but the effects of light and how sunlight will affect a specific design at different times of the day.[6]

Architectural modeling tools have now become increasingly internet-based. However, the quality of internet-based systems still lags behind those of sophisticated in-house modeling systems.[7]

In some applications, computer-generated images are used to "reverse engineer" historical buildings. For instance, a computer-generated reconstruction of the monastery at Georgenthal in Germany was derived from the ruins of the monastery, yet provides the viewer with a "look and feel" of what the building would have looked like in its day.[8]

Anatomical models

SADDLE PE
A CT pulmonary angiogram image generated by a computer from a collection of x-rays.

Computer generated models used in skeletal animation are not always anatomically correct. However, organizations such as the Scientific Computing and Imaging Institute have developed anatomically correct computer-based models. Computer generated anatomical models can be used both for instructional and operational purposes. To date, a large body of artist produced medical images continue to be used by medical students, such as images by Frank H. Netter, e.g. Cardiac images. However, a number of online anatomical models are becoming available.

A single patient X-ray is not a computer generated image, even if digitized. However, in applications which involve CT scans a three-dimensional model is automatically produced from a large number of single slice x-rays, producing "computer generated image". Applications involving magnetic resonance imaging also bring together a number of "snapshots" (in this case via magnetic pulses) to produce a composite, internal image.

In modern medical applications, patient-specific models are constructed in 'computer assisted surgery'. For instance, in total knee replacement, the construction of a detailed patient-specific model can be used to carefully plan the surgery.[9] These three-dimensional models are usually extracted from multiple CT scans of the appropriate parts of the patient's own anatomy. Such models can also be used for planning aortic valve implantations, one of the common procedures for treating heart disease. Given that the shape, diameter, and position of the coronary openings can vary greatly from patient to patient, the extraction (from CT scans) of a model that closely resembles a patient's valve anatomy can be highly beneficial in planning the procedure.[10]

Generating cloth and skin images

Wet Fur - CGI
Computer-generated wet fur

Models of cloth generally fall into three groups:

  • The geometric-mechanical structure at yarn crossing
  • The mechanics of continuous elastic sheets
  • The geometric macroscopic features of cloth.[11]

To date, making the clothing of a digital character automatically fold in a natural way remains a challenge for many animators.[12]

In addition to their use in film, advertising and other modes of public display, computer generated images of clothing are now routinely used by top fashion design firms.[13]

The challenge in rendering human skin images involves three levels of realism:

  • Photo realism in resembling real skin at the static level
  • Physical realism in resembling its movements
  • Function realism in resembling its response to actions.[14]

The finest visible features such as fine wrinkles and skin pores are the size of about 100 µm or 0.1 millimetres. Skin can be modeled as a 7-dimensional bidirectional texture function (BTF) or a collection of bidirectional scattering distribution function (BSDF) over the target's surfaces.

Interactive simulation and visualization

Interactive visualization is the rendering of data that may vary dynamically and allowing a user to view the data from multiple perspectives. The applications areas may vary significantly, ranging from the visualization of the flow patterns in fluid dynamics to specific computer aided design applications.[15] The data rendered may correspond to specific visual scenes that change as the user interacts with the system — e.g. simulators, such as flight simulators, make extensive use of CGI techniques for representing the world.[16]

At the abstract level, an interactive visualization process involves a "data pipeline" in which the raw data is managed and filtered to a form that makes it suitable for rendering. This is often called the "visualization data". The visualization data is then mapped to a "visualization representation" that can be fed to a rendering system. This is usually called a "renderable representation". This representation is then rendered as a displayable image.[16] As the user interacts with the system (e.g. by using joystick controls to change their position within the virtual world) the raw data is fed through the pipeline to create a new rendered image, often making real-time computational efficiency a key consideration in such applications.[16][17]

Computer animation

Machinima films are, by nature, CGI films

While computer generated images of landscapes may be static, the term computer animation only applies to dynamic images that resemble a movie. However, in general, the term computer animation refers to dynamic images that do not allow user interaction, and the term virtual world is used for the interactive animated environments.

Computer animation is essentially a digital successor to the art of stop motion animation of 3D models and frame-by-frame animation of 2D illustrations. Computer generated animations are more controllable than other more physically based processes, such as constructing miniatures for effects shots or hiring extras for crowd scenes, and because it allows the creation of images that would not be feasible using any other technology. It can also allow a single graphic artist to produce such content without the use of actors, expensive set pieces, or props.

To create the illusion of movement, an image is displayed on the computer screen and repeatedly replaced by a new image which is similar to the previous image, but advanced slightly in the time domain (usually at a rate of 24 or 30 frames/second). This technique is identical to how the illusion of movement is achieved with television and motion pictures.

Virtual worlds

Metallic balls
Metallic balls

A virtual world is a simulated environment, which allows the user to interact with animated characters, or interact with other users through the use of animated characters known as avatars. Virtual worlds are intended for its users to inhabit and interact, and the term today has become largely synonymous with interactive 3D virtual environments, where the users take the form of avatars visible to others graphically.[18] These avatars are usually depicted as textual, two-dimensional, or three-dimensional graphical representations, although other forms are possible[19] (auditory[20] and touch sensations for example). Some, but not all, virtual worlds allow for multiple users.

In courtrooms

Computer-generated imagery has been used in courtrooms, primarily since the early 2000s. However, some experts have argued that it is prejudicial. They are used to help judges or the jury to better visualize the sequence of events, evidence or hypothesis.[21] However, a 1997 study showed that people are poor intuitive physicists and easily influenced by computer generated images.[22] Thus it is important that jurors and other legal decision-makers be made aware that such exhibits are merely a representation of one potential sequence of events.

See also

References

  1. ^ a b c Peitgen 2004, pp. 462–466.
  2. ^ Game programming gems 2 by Mark A. DeLoura 2001 ISBN 1-58450-054-9 page 240 [1]
  3. ^ Digital modeling of material appearance by Julie Dorsey, Holly E. Rushmeier, François X. Sillion 2007 ISBN 0-12-221181-2 page 217
  4. ^ Sondermann 2008, pp. 8–15.
  5. ^ Interactive environments with open-source software: 3D walkthroughs by Wolfgang Höhl, Wolfgang Höhl 2008 ISBN 3-211-79169-8 pages 24-29
  6. ^ Advances in Computer and Information Sciences and Engineering by Tarek Sobh 2008 ISBN 1-4020-8740-3 pages 136-139
  7. ^ Encyclopedia of Multimedia Technology and Networking, Volume 1 by Margherita Pagani 2005 ISBN 1-59140-561-0 page 1027
  8. ^ Interactive storytelling: First Joint International Conference by Ulrike Spierling, Nicolas Szilas 2008 ISBN 3-540-89424-1 pages 114-118
  9. ^ Total Knee Arthroplasty by Johan Bellemans, Michael D. Ries, Jan M.K. Victor 2005 ISBN 3-540-20242-0 pages 241-245
  10. ^ I. Waechter et al. Patient Specific Models for Minimally Invasive Aortic Valve Implantation in Medical Image Computing and Computer-Assisted Intervention -- MICCAI 2010 edited by Tianzi Jiang, 2010 ISBN 3-642-15704-1 pages 526-560
  11. ^ Cloth modeling and animation by Donald House, David E. Breen 2000 ISBN 1-56881-090-3 page 20
  12. ^ Film and photography by Ian Graham 2003 ISBN 0-237-52626-3 page 21
  13. ^ Designing clothes: culture and organization of the fashion industry by Veronica Manlow 2007 ISBN 0-7658-0398-4 page 213
  14. ^ Handbook of Virtual Humans by Nadia Magnenat-Thalmann and Daniel Thalmann, 2004 ISBN 0-470-02316-3 pages 353-370
  15. ^ Mathematical optimization in computer graphics and vision by Luiz Velho, Paulo Cezar Pinto Carvalho 2008 ISBN 0-12-715951-7 page 177
  16. ^ a b c GPU-based interactive visualization techniques by Daniel Weiskopf 2006 ISBN 3-540-33262-6 pages 1-8
  17. ^ Trends in interactive visualization by Elena van Zudilova-Seinstra, Tony Adriaansen, Robert Liere 2008 ISBN 1-84800-268-8 pages 1-7
  18. ^ Cook, A.D. (2009). A case study of the manifestations and significance of social presence in a multi-user virtual environment. MEd Thesis. Available online
  19. ^ Biocca & Levy 1995, pp. 40–44.
  20. ^ Begault 1994, p. 212.
  21. ^ Computer-generated images influence trial results The Conversation, 31 October 2013
  22. ^ Kassin, S. M. (1997). "Computer-animated Display and the Jury: Facilitative and Prejudicial Effects". Law and Human Behavior. 40 (3): 269–281. doi:10.1023/a:1024838715221. [2]

Bibliography

  • Begault, Durand R. (1994). 3-D Sound for Virtual Reality and Multimedia. AP Professional. ISBN 978-0-1208-4735-8.
  • Biocca, Frank; Levy, Mark R. (1995). Communication in the Age of Virtual Reality. Lawrence Erlbaum Associates. ISBN 978-0-8058-1549-8.
  • Peitgen, Heinz-Otto; Jürgens, Hartmut; Saupe, Dietmar (2004). Chaos and Fractals: New Frontiers of Science. Springer Science & Business Media. ISBN 978-0-387-20229-7.
  • Sondermann, Horst (2008). Light Shadow Space: Architectural Rendering with Cinema 4D. Vienna: Springer. ISBN 978-3-211-48761-7.

External links

30,000 Leagues Under the Sea

30,000 Leagues Under the Sea is a 2007 film directed by Gabriel Bologna. It is a modern update on the classic book 20,000 Leagues Under the Sea, and stars Lorenzo Lamas as Lt. Aronnaux and Sean Lawlor as the misanthropic Captain Nemo. It also stars Natalie Stone, Kerry Washington, and Kim Little.

The film is the first by The Asylum to be based on a Jules Verne novel, with Journey to the Center of the Earth following in 2008.

Animation World Network

Animation World Network (often just "AWN") is an online publishing group that specializes in resources for animators, with an extensive website offering news, articles and links for professional animators and animation fans. AWN also publishes print magazines. The magazines are Animation World, dedicated to animation in general, and VFX World, which focuses on special effects and computer-generated imagery.

Casper (film)

Casper is a 1995 American fantasy comedy film directed by Brad Silberling, based on the Harvey Comics cartoon character Casper the Friendly Ghost created by Seymour Reit and Joe Oriolo. The film stars Christina Ricci, Bill Pullman, Cathy Moriarty, Eric Idle, and Amy Brenneman, and also features the voices of Malachi Pearson in the title role as well as Joe Nipote, Joe Alaskey, and Brad Garrett.

The film makes extensive use of computer-generated imagery to create the ghosts, and it is the first feature film to have a fully CGI character in the lead role. It goes for a much darker interpretation of the Friendly Ghost in comparison to the comics, cartoons, and films of the previous years, especially with its theme of death, most notably providing the character a tragic backstory that addresses his death.

Casper was released in cinemas on May 26, 1995 by Universal Pictures. It received mixed reviews from critics and earned $287.9 million on a $55 million budget. It went on to spawn direct-to-video follow-up films and an animated television spin-off, The Spooktacular New Adventures of Casper.

Deep Rising

Deep Rising is a 1998 American action horror film directed by Stephen Sommers and starring Treat Williams, Famke Janssen and Anthony Heald. It was distributed by Hollywood Pictures and Cinergi Pictures and released on January 30, 1998.

Krishnarjuna

Krishnarjuna is a 2008 Telugu language film produced by M.Mohan Babu on his Sri Lakshmi Prasanna Pictures banner and directed by P. Vasu. Starring Nagarjuna Akkineni, Manchu Vishnu, Mamta Mohandas in the lead roles, Mohan Babu in cameo appearance and music composed by M. M. Keeravani. The film recorded as flop at box-office.The film was later dubbed into Hindi under the same name by Wide Angle Media Pvt Ltd in 2013.

Monster Family

Monster Family (also known as Happy Family) is a 2017 British-German computer animated horror comedy film directed and produced by Holger Tappe, and co-written by David Safier. It is based on David Safier's children's book Happy Family. The film stars Emily Watson, Nick Frost, Jessica Brown Findlay, Celia Imrie, Catherine Tate, and Jason Isaacs. The film performed poorly with critics and was panned by audiences.

Nagarahavu (2016 film)

Nagarahavu (Kannada: ನಾಗರಹಾವು, English: Cobra) is a 2016 Indian Kannada language epic-fantasy film directed by Kodi Ramakrishna, who made his directorial debut in Kannada cinema, and produced by Sajid Qureshi, Inbox Pictures Pvt Ltd. With Ramya in the leading role, a digitally recreated CGI version of deceased actor Dr.Vishnuvardhan has played main role, with the film being marketed as his "comeback". The film has been dubbed and released in Tamil as Shivanagam, Telugu as Nagabharanam' and Hindi as Nagavanshi. The film released on 14 October 2016.

It was festive season to fans for having come back of legendary actor Dr.Vishnuvardhan through CGI effect.

Piranhaconda

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Practical effect

A practical effect is a special effect produced physically, without computer-generated imagery or other post production techniques. In some contexts, "special effect" is used as a synonym of "practical effect", in contrast to "visual effects" which are created in post-production through photographic manipulation or computer generation.

Many of the staples of action movies are practical effects. Gunfire, bullet wounds, rain, wind, fire, and explosions can all be produced on a movie set by someone skilled in practical effects. Non-human characters and creatures produced with make-up, prosthetics, masks, and puppets – in contrast to computer-generated images – are also examples of practical effects.

Sharktopus

Sharktopus is a 2010 SyFy original horror/science fiction film produced by Roger Corman, directed by Declan O'Brien, and starring Eric Roberts. It is the first film in the Sharktopus franchise.

Special effect

Special effects (often abbreviated as SFX, SPFX, or simply FX) are illusions or visual tricks used in the film, television, theatre, video game and simulator industries to simulate the imagined events in a story or virtual world.

Special effects are traditionally divided into the categories of mechanical effects and optical effects. With the emergence of digital film-making a distinction between special effects and visual effects has grown, with the latter referring to digital post-production while "special effects" referring to mechanical and optical effects.

Mechanical effects (also called practical or physical effects) are usually accomplished during the live-action shooting. This includes the use of mechanized props, scenery, scale models, animatronics, pyrotechnics and atmospheric effects: creating physical wind, rain, fog, snow, clouds, making a car appear to drive by itself and blowing up a building, etc. Mechanical effects are also often incorporated into set design and makeup. For example, a set may be built with break-away doors or walls to enhance a fight scene, or prosthetic makeup can be used to make an actor look like a non-human creature.

Optical effects (also called photographic effects) are techniques in which images or film frames are created photographically, either "in-camera" using multiple exposure, mattes or the Schüfftan process or in post-production using an optical printer. An optical effect might be used to place actors or sets against a different background.

Since the 1990s, computer-generated imagery (CGI) has come to the forefront of special effects technologies. It gives filmmakers greater control, and allows many effects to be accomplished more safely and convincingly and—as technology improves—at lower costs. As a result, many optical and mechanical effects techniques have been superseded by CGI.

Terminator (character concept)

In the Terminator film series, a Terminator is an autonomous killer robot, typically humanoid, originally conceived as a virtually indestructible soldier, infiltrator and assassin.

James Cameron introduced the first Terminator character in the 1984 film The Terminator, featuring a single android simply called "The Terminator", portrayed by Arnold Schwarzenegger. When later Terminator films introduced additional models, some sources retroactively gave Schwarzenegger's character a model number, leading to multiple conflicting names.

The Keeper (2018 film)

The Keeper is a British-German biographical film directed by Marcus H. Rosenmüller and starring German actor David Kross as the footballer Bert Trautmann. Although the subject of the film was a sportsman, the film has been described as "not primarily a sports film" but instead a drama.The film premiered at the 2018 Zurich Film Festival, and is slated for commercial release in 2019.

The Last Starfighter

The Last Starfighter is a 1984 American space opera film directed by Nick Castle. The film tells the story of Alex Rogan (Lance Guest), an average teenager recruited by an alien defense force to fight in an interstellar war. It also features Robert Preston, Dan O'Herlihy, Catherine Mary Stewart, Norman Snow, and Kay E. Kuter.

The Last Starfighter, along with Disney's Tron, has the distinction of being one of cinema's earliest films to use extensive computer-generated imagery (CGI) to depict its many starships, environments and battle scenes. It is one of the first films to use CGI to represent "real-life" objects instead of digital graphics.

The Last Starfighter was Preston's final role on the big screen (though he would do cameos in TV movies afterwards until his death in 1987). His character, a "lovable con-man", was a nod to his most famous role as Harold Hill in The Music Man. There was a subsequent novelization of the film by Alan Dean Foster, as well as a video game based on the production. In 2004, it was also adapted as an off-Broadway musical.

The Mummy Returns

The Mummy Returns is a 2001 American action-adventure fantasy film written and directed by Stephen Sommers, starring Brendan Fraser, Rachel Weisz, John Hannah, Arnold Vosloo, Oded Fehr, Patricia Velásquez, and Dwayne "The Rock" Johnson. The film is a sequel to the 1999 film The Mummy.

The Mummy Returns inspired the 2002 prequel film The Scorpion King which is set 5,000 years prior and whose eponymous character, played by Dwayne "The Rock" Johnson, was introduced in this film. It was followed by the 2008 sequel The Mummy: Tomb of the Dragon Emperor.

The Ring Two

The Ring Two (stylized as the ring twO) is a 2005 American supernatural psychological horror film and a sequel to the 2002 film The Ring, which was a remake of the 1998 Japanese film Ringu. Hideo Nakata, director of the original Japanese film Ringu, on which the American versions are based, directed this film in place of Gore Verbinski.

The film was shot in Astoria, Oregon and Los Angeles, California. It was released on March 18, 2005, and although it was met by generally negative critical reception, it opened in the United States with a strong US$35 million its first weekend, more than doubling the opening weekend of The Ring. Its final $76 million domestic gross was less than the original's $129 million, but it took $85 million internationally, for a total gross of $161 million.

It is the second installment in The Ring film series and was followed by Rings (2017).

Visual effects

Visual effects (abbreviated VFX) is the process by which imagery is created or manipulated outside the context of a live action shot in film making.

Visual effects involve the integration of live-action footage (special effects) and generated imagery (digital effects) to create environments which look realistic, but would be dangerous, expensive, impractical, time consuming or impossible to capture on film. Visual effects using computer-generated imagery (CGI) have recently become accessible to the independent filmmaker with the introduction of affordable and easy-to-use animation and compositing software.

Wish Dragon

Wish Dragon is an upcoming computer-animated comedy film written and co-directed by Chris Appelhans and Amy Heckerling. Produced by Sony Pictures Animation, Base FX and the Flagship Entertainment Group, the film will star Jackie Chan (who is also producing the film), Constance Wu, Natasha Liu Bordizzo, Will Yun Lee, Jimmy Wong, and Bobby Lee. It is set to be released on July 26, 2019 by Sony Pictures Releasing.

Jackie Chan's company, Sparkle Roll Media, will be a producer and co-investor in the film. Chan will voice characters in the Chinese and English releases of the film.The story is "a genie-in-a-bottle retelling set in contemporary China", based on an original story by Chris Appelhans. Appelhans will also direct the film "The modern-day fairy tale picks up the moral challenges that emerge from the encounter between a boy and a dragon who is able to make wishes come true."

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