A light stage or light cage is equipment used for

shape A shape or figure is a graphical representation of an object or its external boundary, outline, or external surface, as opposed to other properties such as color, texture, or material type. A plane shape or plane figure is constrained to lie ...

texture Texture may refer to: Science and technology * Surface texture, the texture means smoothness, roughness, or bumpiness of the surface of an object * Texture (roads), road surface characteristics with waves shorter than road roughness * Texture ...

, reflectance and motion capture often with structured light and a

multi-camera setup The multiple-camera setup, multiple-camera mode of production, multi-camera or simply multicam is a method of filmmaking and video production. Several cameras—either film or professional video cameras—are employed on the set and simultaneous ...

Reflectance capture

The reflectance field over a

human face The face is the front of an animal's head that features the eyes, nose and mouth, and through which animals express many of their emotions. The face is crucial for human identity, and damage such as scarring or developmental deformities may aff ...

was first captured in 1999 by

Paul Debevec Paul Ernest Debevec is a researcher in computer graphics at the University of Southern California's Institute for Creative Technologies. He is best known for his work in finding, capturing and synthesizing the bidirectional scattering distribution ...

Tim Hawkins Timothy Aaron Hawkins (born March 30, 1968) is an American Christian comedian, songwriter, and singer, best known for parodying popular songs such as Carrie Underwood's "Jesus, Take the Wheel", Kansas's " Dust in the Wind", and "The Candy Man", ...

et al and presented in SIGGRAPH 2000. The method they used to find the light that travels under the skin was based on the existing

scientific knowledge Science is a systematic endeavor that builds and organizes knowledge in the form of testable explanations and predictions about the universe. Science may be as old as the human species, and some of the earliest archeological evidence for ...

that light reflecting off the air-to-oil retains its polarization while light that travels under the skin loses its polarization. Using this information, a light stage was built by Debevec et al., consisting of # Moveable

digital camera A digital camera is a camera that captures photographs in digital memory. Most cameras produced today are digital, largely replacing those that capture images on photographic film. Digital cameras are now widely incorporated into mobile devices ...

# Moveable simple

light source Light or visible light is electromagnetic radiation that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 terah ...

(full rotation with adjustable

radius In classical geometry, a radius ( : radii) of a circle or sphere is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length. The name comes from the latin ''radius'', meaning ray but also the ...

and height) # Two polarizers set into various

angle In Euclidean geometry, an angle is the figure formed by two rays, called the '' sides'' of the angle, sharing a common endpoint, called the '' vertex'' of the angle. Angles formed by two rays lie in the plane that contains the rays. Angles a ...

s in front of the light and the camera # A computer with relatively simple programs doing relatively simple tasks. The setup enabled the team to find the

subsurface scattering Subsurface scattering (SSS), also known as subsurface light transport (SSLT), is a mechanism of light transport in which light that penetrates the surface of a translucent object is scattered by interacting with the material and exits the surfa ...

component of the bidirectional scattering distribution function over the human face which was required for fully virtual cinematography with ultra-photorealistic digital look-alikes, similar to effects seen in the films ''

The Matrix Reloaded ''The Matrix Reloaded'' is a 2003 American science-fiction action film written and directed by the Wachowskis. It is a sequel to '' The Matrix'' (1999) and the second installment in the ''Matrix'' film series. The film stars Keanu Reeves, Lau ...

'', ''

The Matrix Revolutions ''The Matrix Revolutions'' is a 2003 American science fiction action film written and directed by the Wachowskis. It is the third installment in ''The Matrix'' film series, released six months following ''The Matrix Reloaded''. The film stars ...

'' and others since the early 2000s. Following great scientific success Debevec et al. constructed more elaborate versions of the light stage at the

University of Southern California , mottoeng = "Let whoever earns the palm bear it" , religious_affiliation = Nonsectarian—historically Methodist , established = , accreditation = WSCUC , type = Private research university , academic_affiliations = , endowment = $8.1 ...

's (USC)'s

Institute for Creative Technologies An institute is an organisational body created for a certain purpose. They are often research organisations (research institutes) created to do research on specific topics, or can also be a professional body. In some countries, institutes can ...

(ICT). Ghosh et al. built the seventh version of the USC light stage X. In 2014 President

Barack Obama Barack Hussein Obama II ( ; born August 4, 1961) is an American politician who served as the 44th president of the United States from 2009 to 2017. A member of the Democratic Party, Obama was the first African-American president of the ...

had his image and reflectance captured with the USC mobile light stage.

Examples of use

* Human image synthesis is hard to tell apart from a human imaged with an

imaging Imaging is the representation or reproduction of an object's form; especially a visual representation (i.e., the formation of an image). Imaging technology is the application of materials and methods to create, preserve, or duplicate images. ...

technology **Digital Emily presented to the SIGGRAPH convention in 2008 was a project whereby the reflection field of

actress An actor or actress is a person who portrays a character in a performance. The actor performs "in the flesh" in the traditional medium of the theatre or in modern media such as film, radio, and television. The analogous Greek term is (), li ...

Emily O'Brien Emily Roya O'Brien (born 28 May 1985) is an English three-time Daytime Emmy-nominated actress and writer who is known for her five-year series regular role of Jana Hawkes Fisher on ''The Young and the Restless'' from 2006–2011. She portrayed ...

was captured using the USC light stage 5,Paul Debevec animates a photo-real digital face - Digital Emily
2008 and the prerendered digital look-alike was made in association with

Image Metrics Image Metrics is a 3D facial animation and Virtual Try-on company headquartered in El Segundo, with offices in Las Vegas, and research facilities in Manchester. Image Metrics are the makers of the Live Driver and Portable You SDKs for softw ...

. Video came from USC light stage 5 and USC light stage 6. ** Digital Ira was a fairly convincingly rendered

real-time Real-time or real time describes various operations in computing or other processes that must guarantee response times within a specified time (deadline), usually a relatively short time. A real-time process is generally one that happens in defined ...

image that was presented at the 2013 SIGGRAPH in association with

Activision Activision Publishing, Inc. is an American video game publisher based in Santa Monica, California. It serves as the publishing business for its parent company, Activision Blizzard, and consists of several subsidiary studios. Activision is one ...

. While Digital Emily was a pre-computed simulation, Digital Ira ran in real-time and was fairly realistic looking even as a

real-time rendering Real-time computer graphics or real-time rendering is the sub-field of computer graphics focused on producing and analyzing images in real time. The term can refer to anything from rendering an application's graphical user interface ( GUI) to ...

of animation. The field is rapidly moving from

movies A film also called a movie, motion picture, moving picture, picture, photoplay or (slang) flick is a work of visual art that simulates experiences and otherwise communicates ideas, stories, perceptions, feelings, beauty, or atmosphere ...

to computer games and

leisure Leisure has often been defined as a quality of experience or as free time. Free time is time spent away from business, work, job hunting, domestic chores, and education, as well as necessary activities such as eating and sleeping. Leisur ...

applications Application may refer to: Mathematics and computing * Application software, computer software designed to help the user to perform specific tasks ** Application layer, an abstraction layer that specifies protocols and interface methods used in a c ...

– Video includes USC light stage X. ** The Presidential Portrait by USC ICT in conjunction with the

Smithsonian Institution The Smithsonian Institution ( ), or simply the Smithsonian, is a group of museums and education and research centers, the largest such complex in the world, created by the U.S. government "for the increase and diffusion of knowledge". Founded ...

was done using the latest mobile light stage. It included texture, feature and reflectance capture with high resolution multi-camera setup and also additional hand held scanners. A

3D printed 3D printing or additive manufacturing is the construction of a three-dimensional object from a CAD model or a digital 3D model. It can be done in a variety of processes in which material is deposited, joined or solidified under computer co ...

bust of the President was also produced. **ESPER LightCage a geodesic frame with cross-polarized which can be programmed to create realistic lighting conditions for capturing images suitable for processing into high resolution 3D meshes. Allows to emulate the pioneering techniques developed by Paul Debevec and the USC ICT for generating diffuse maps, normal maps, specular maps and sub-surface scattering maps.

References

{{reflist 3D computer graphics Nonimaging optics