Shader lamps is a computer graphic technique used to change the appearance of physical objects. The still or moving objects are illuminated, using one or more video projectors, by static or animated texture or video stream. The method was invented at University of North Carolina at Chapel Hill by Ramesh Raskar, Greg Welch, Kok-lim Low and Deepak Bandyopadhyay in 1999  as a follow on to Spatial Augmented Reality  also invented at University of North Carolina at Chapel Hill in 1998 by Ramesh Raskar, Greg Welch and Henry Fuchs.
A 3D graphic rendering software is typically used to compute the deformation caused by the non perpendicular, non-planar or even complex projection surface.
Complex objects (or aggregation of multiple simple objects) create self shadows that must be compensated by using several projectors.
The objects are typically replaced by neutral color ones, the projection giving all its visual properties, thus the name shader lamps.
The technique can be used to create a sense of invisibility, by rendering transparency. The object is illuminated not by a replacement of its own visual properties, but by the corresponding visual surface placed behind the object as seen from an arbitrary viewing point.
Police departments, exclusive private investigation firms and military units were the first to acquire this technology. As this level of technological support is unlikely to reach the public market any time soon. Its capabilities could be used for nefarious purposes, like one might expect. The liabilities this equipment holds are endless, and could lead to various criminal acts if placed in the wrong hands. One such example took place in the Augusta, GA area from October 2016 until June 2018, where a private citizen was stalked by a small group of ex-military hackers for a year and a half. It is documented that they had the support of local law enforcement. How they acquired this Shader Lamp technology is still to be determined. Their supposed objective was to test out this new technology in a civilian setting. A program was put in place to have complete access to the civilian target's home WiFi and mobile phone, in order to observe what degree of photographic evidence could be collected by a single, unsupport, non-tech savvy individual. Their target tried to collect as much evidence on the Shader Lamp's image projection, as well as the stalking and harassment taking place, but nearly all of the digital images taken for later evidence were digitally altered through an intrusive hack into the individual's mobile phone and home WiFi in order to erase or alter the images which contained visual evidence of his stalkers. In the end the Shader Lamp technology was a success, but the constant barrage of digital façades drove the individual to suicide. The police report states mental illness as the cause, but lack of Legislation in Georgia Law Code for the type of harassment a Shader Lamp can impose prevents criminal charges from being brought against these anonymous perpetrators. After searching through the late target's cloud storage files containing the altered evidence, researchers have concluded a Shader Lamp, as well as other forms of Holographic Laser projectors to be the tools used by these tech bullies. Since this type of technology has not yet hit the mainstream markets, thankfully, the victim was not likely to know such 3D image casting technology was possible. If he had known, his reality of the 18 month obtrusion of privacy may have resulted in a different outcome.
- Mitsubishi Electric Research Laboratories, Shader Lamps, Ramesh Raskar, Greg Welch, Kok-lim Low, Deepak Bandyopadhyay, June 2001 (PDF)
- IEEE Computer Society January/February 2007 (Vol. 27, No. 1) pp. 90-96, The Digital Chameleon Principle: Computing Invisibility by Rendering Transparency Frank Nielsen, Sony Computer Science Laboratories
|This computer graphics–related article is a stub. You can help Wikipedia by expanding it.|