A light stage is an active illumination system used for

shape A shape is a graphics, graphical representation of an object's form or its external boundary, outline, or external Surface (mathematics), surface. It is distinct from other object properties, such as color, Surface texture, texture, or material ...

texture Texture may refer to: Science and technology * Image texture, the spatial arrangement of color or intensities in an image * Surface texture, the smoothness, roughness, or bumpiness of the surface of an object * Texture (roads), road surface c ...

, reflectance and

motion capture 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 ...

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, television production and video production. Several cameras—either film cameras, film or professional video cameras—are ...

Reflectance capture

The reflectance field over a

human face The face is the front of the 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 affect t ...

was first captured in 1999 by Paul Debevec, Tim Hawkins et al and presented in

SIGGRAPH SIGGRAPH (Special Interest Group on Computer Graphics and Interactive Techniques) is an annual conference centered around computer graphics organized by ACM, starting in 1974 in Boulder, CO. The main conference has always been held in North ...

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 discipline that builds and organises knowledge in the form of testable hypotheses and predictions about the universe. Modern science is typically divided into twoor threemajor branches: the natural sciences, which stu ...

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, also called a digicam, is a camera that captures photographs in Digital data storage, digital memory. Most cameras produced today are digital, largely replacing those that capture images on photographic film or film stock. Dig ...

# Moveable simple

light source Light, visible light, or visible radiation is electromagnetic radiation that can be visual perception, perceived by the human eye. Visible light spans the visible spectrum and is usually defined as having wavelengths in the range of 400– ...

(full

rotation Rotation or rotational/rotary motion is the circular movement of an object around a central line, known as an ''axis of rotation''. A plane figure can rotate in either a clockwise or counterclockwise sense around a perpendicular axis intersect ...

with adjustable

radius In classical geometry, a radius (: radii or radiuses) of a circle or sphere is any of the line segments from its Centre (geometry), center to its perimeter, and in more modern usage, it is also their length. The radius of a regular polygon is th ...

and height) # Two

polarizer A polarizer or polariser is an optical filter that lets light waves of a specific polarization (waves), polarization pass through while attenuation, blocking light waves of other polarizations. It can filter a beam of light of undefined or mixed ...

s set into various

angle In Euclidean geometry, an angle can refer to a number of concepts relating to the intersection of two straight Line (geometry), lines at a Point (geometry), point. Formally, an angle is a figure lying in a Euclidean plane, plane formed by two R ...

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 scattering, scattered by interacting with the Material (comput ...

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 the sequel to ''The Matrix'' (1999) and the second installment in the ''Matrix'' film series. The film stars Keanu Reeves, L ...

'', ''

The Matrix Revolutions ''The Matrix Revolutions'' is a 2003 American science fiction action film written and directed by the Wachowskis. The direct sequel to ''The Matrix Reloaded,'' it is the third installment in ''The Matrix'' film series, released six months foll ...

'' 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 The University of Southern California (USC, SC, or Southern Cal) is a Private university, private research university in Los Angeles, California, United States. Founded in 1880 by Robert M. Widney, it is the oldest private research university in ...

's (USC)'s Institute for Creative Technologies (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 was the 44th president of the United States from 2009 to 2017. A member of the Democratic Party, he was the first African American president in American history. O ...

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 (masculine/gender-neutral), or actress (feminine), is a person who portrays a character in a production. The actor performs "in the flesh" in the traditional medium of the theatre or in modern media such as film, radio, and television. ...

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

real-time Real-time, realtime, or real time may refer to: Computing * Real-time computing, hardware and software systems subject to a specified time constraint * Real-time clock, a computer clock that keeps track of the current time * Real-time Control Syst ...

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 o ...

. 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 of

animation Animation is a filmmaking technique whereby still images are manipulated to create moving images. In traditional animation, images are drawn or painted by hand on transparent celluloid sheets to be photographed and exhibited on film. Animati ...

. The field is rapidly moving from

movies A film, also known as a movie or motion picture, is a work of visual art that simulates experiences and otherwise communicates ideas, stories, perceptions, emotions, or atmosphere through the use of moving images that are generally, since ...

computer games A video game or computer game is an electronic game that involves interaction with a user interface or input device (such as a joystick, game controller, controller, computer keyboard, keyboard, or motion sensing device) to generate visual fe ...

and

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

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 ...

– 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, Education center, education and Research institute, research centers, created by the Federal government of the United States, U.S. government "for the increase a ...

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 bust of the President was also produced.

References

{{reflist 3D computer graphics Nonimaging optics