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Radiance (software)
Radiance is a suite of tools for performing '' lighting simulation'' originally written by Greg Ward. It includes a renderer as well as many other tools for measuring the simulated light levels. It uses ray tracing to perform all lighting calculations, accelerated by the use of an octree data structure. It pioneered the concept of high-dynamic-range imaging, where light levels are (theoretically) open-ended values instead of a decimal proportion of a maximum (e.g. 0.0 to 1.0) or integer fraction of a maximum (0 to 255 / 255). It also implements global illumination using the Monte Carlo method to sample light falling on a point. Greg Ward started developing Radiance in 1985 while at Lawrence Berkeley National Laboratory. The source code was distributed under a license forbidding further redistribution. In January 2002 Radiance 3.4 was relicensed under a less restrictive license. One study found Radiance to be the most generally useful software package for architectural lightin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C (programming Language)
C (''pronounced'' '' – like the letter c'') is a general-purpose programming language. It was created in the 1970s by Dennis Ritchie and remains very widely used and influential. By design, C's features cleanly reflect the capabilities of the targeted Central processing unit, CPUs. It has found lasting use in operating systems code (especially in Kernel (operating system), kernels), device drivers, and protocol stacks, but its use in application software has been decreasing. C is commonly used on computer architectures that range from the largest supercomputers to the smallest microcontrollers and embedded systems. A successor to the programming language B (programming language), B, C was originally developed at Bell Labs by Ritchie between 1972 and 1973 to construct utilities running on Unix. It was applied to re-implementing the kernel of the Unix operating system. During the 1980s, C gradually gained popularity. It has become one of the most widely used programming langu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Floating Point
In computing, floating-point arithmetic (FP) is arithmetic on subsets of real numbers formed by a ''significand'' (a signed sequence of a fixed number of digits in some base) multiplied by an integer power of that base. Numbers of this form are called floating-point numbers. For example, the number 2469/200 is a floating-point number in base ten with five digits: 2469/200 = 12.345 = \! \underbrace_\text \! \times \! \underbrace_\text\!\!\!\!\!\!\!\overbrace^ However, 7716/625 = 12.3456 is not a floating-point number in base ten with five digits—it needs six digits. The nearest floating-point number with only five digits is 12.346. And 1/3 = 0.3333… is not a floating-point number in base ten with any finite number of digits. In practice, most floating-point systems use base two, though base ten (decimal floating point) is also common. Floating-point arithmetic operations, such as addition and division, approximate the corresponding real number arithmetic operations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesopic Vision
Mesopic vision, sometimes also called twilight vision, is a combination of photopic and scotopic vision under low-light (but not necessarily dark) conditions. Mesopic levels range approximately from 0.01 to 3.0 cd/m2 in luminance. Most nighttime outdoor and street lighting conditions are in the mesopic range. Human eyes respond to certain light levels differently. This is because under high light levels typical during daytime (photopic vision), the eye uses cones to process light. Under very low light levels, corresponding to moonless nights without artificial lighting (scotopic vision), the eye uses rods to process light. At many nighttime levels, a combination of both cones and rods supports vision. Photopic vision facilitates excellent color perception, whereas colors are barely perceptible under scotopic vision. Mesopic vision falls between these two extremes. In most nighttime environments, enough ambient light prevents true scotopic vision. In the words of Duco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spatial Anti-aliasing
In digital signal processing, spatial anti-aliasing is a technique for minimizing the distortion artifacts (aliasing) when representing a high-resolution image at a lower resolution. Anti-aliasing is used in digital photography, computer graphics, digital audio, and many other applications. Anti-aliasing means removing signal components that have a higher frequency than is able to be properly resolved by the recording (or sampling) device. This removal is done before (re)sampling at a lower resolution. When sampling is performed without removing this part of the signal, it causes undesirable artifacts such as black-and-white noise. In signal acquisition and audio, anti-aliasing is often done using an analog anti-aliasing filter to remove the out-of-band component of the input signal prior to sampling with an analog-to-digital converter. In digital photography, optical anti-aliasing filters made of birefringent materials smooth the signal in the spatial optical domain. The anti-a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glare (vision)
Glare is difficulty of seeing in the presence of bright light such as direct or reflected sunlight or artificial light such as car headlamps at night. Because of this, some cars include mirrors with automatic anti-glare functions and in buildings, blinds or louvers are often used to protect occupants. Glare is caused by a significant ratio of luminance between the task (that which is being looked at) and the glare source. Factors such as the angle between the task and the glare source and eye adaptation have significant impacts on the experience of glare. Discomfort and disability Glare can be generally divided into two types, discomfort glare and disability glare. Discomfort glare is a psychological sensation caused by high brightness (or brightness contrast) within the field of view, which does not necessarily impair vision. In buildings, discomfort glare can originate from small artificial lights (e.g. ceiling fixtures) that have brightnesses that are significantly greater tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daylight Factor
In architecture, a daylight factor (DF) is the ratio of the light level inside a structure to the light level outside the structure. It is defined as: :''DF = (Ei / Eo) x 100%'' where, ''Ei'' = illuminance due to daylight at a point on the indoors working plane, ''Eo'' = simultaneous outdoor illuminance on a horizontal plane from an unobstructed hemisphere of overcast sky. To calculate ''Ei'', requires knowing the amount of outside light received inside of a building. Light can reach a room via through a glazed window, rooflight, or other aperture via three paths: * Direct light from a patch of sky visible at the point considered, known as the sky component (''SC''), * Light reflected from an exterior surface and then reaching the point considered, known as the externally reflected component (''ERC''), * Light entering through the window but reaching the point only after reflection from an internal surface, known as the internally reflected component (''IRC''). The sum of the thr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X Window System
The X Window System (X11, or simply X) is a windowing system for bitmap displays, common on Unix-like operating systems. X originated as part of Project Athena at Massachusetts Institute of Technology (MIT) in 1984. The X protocol has been at version 11 (hence "X11") since September 1987. The X.Org Foundation leads the X project, with the current reference implementation, X.Org Server, available as free and open-source software under the MIT License and similar permissive licenses. Purpose and abilities X is an architecture-independent system for remote graphical user interfaces and input device capabilities. Each person using a networked computer terminal, terminal has the ability to interact with the display with any type of user input device. In its standard distribution it is a complete, albeit simple, display and interface solution which delivers a standard widget toolkit, toolkit and protocol stack for building graphical user interfaces on most Unix-like operating syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alias Wavefront
Alias Systems Corporation (formerly Alias Research, Alias, Wavefront), headquartered in Toronto, Ontario, Canada, was a software company that produced high-end 3D graphics software. Alias was eventually bought by Autodesk. History Alias Systems Corporation was founded by Stephen Bingham, Nigel McGrath, Susan McKenna, and David Springer in 1983. The company was initially funded by a $61,000 grant from the National Research Council, scientific research tax credits, and the founders personal funds. In 1984, while sitting in a Detroit restaurant during the SIGGRAPH conference, the founders decided to name the company Alias because its only revenue came from Springer's work on an anti-aliasing program for Silicon Graphics, Inc. In 1985, at SIGGRAPH, the company released Alias 1, which used cardinal splines instead of polygon meshes with straight lines. In 1989, Alias 2 was used to produce ''The Abyss'' which would later win the 1990 Academy Award for Best Visual Effects. In 1990, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Commission On Illumination
The International Commission on Illumination (usually abbreviated CIE for its French name Commission internationale de l'éclairage) is the international authority on light, illumination, colour, and colour spaces. It was established in 1913 as a successor to the Commission Internationale de Photométrie, which was founded in 1900, and is today based in Vienna, Austria. Organization The CIE has six active divisions, each of which establishes technical committees to carry out its program: * Division 1: Vision and Colour * Division 2: Physical Measurement of Light and Radiation * Division 3: Interior Environment and Lighting Design * Division 4: Transportation and Exterior Applications * Division 6: Photobiology and Photochemistry * Division 8: Image Technology Two divisions are no longer active. * Division 5: Exterior Lighting and Other Applications * Division 7: General Aspects of Lighting The President of the CIE from 2023 is Jennifer Veitch from Canada. CIE publi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface Of Revolution
A surface of revolution is a Surface (mathematics), surface in Euclidean space created by rotating a curve (the ''generatrix'') one full revolution (unit), revolution around an ''axis of rotation'' (normally not Intersection (geometry), intersecting the generatrix, except at its endpoints). The volume bounded by the surface created by this revolution is the ''solid of revolution''. Examples of surfaces of revolution generated by a straight line are cylinder (geometry), cylindrical and conical surfaces depending on whether or not the line is parallel to the axis. A circle that is rotated around any diameter generates a sphere of which it is then a great circle, and if the circle is rotated around an axis that does not intersect the interior of a circle, then it generates a torus which does not intersect itself (a ring torus). Properties The sections of the surface of revolution made by planes through the axis are called ''meridional sections''. Any meridional section can be consi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Output
Standard may refer to: Symbols * Colours, standards and guidons, kinds of military signs * Standard (emblem), a type of a large symbol or emblem used for identification Norms, conventions or requirements * Standard (metrology), an object that bears a defined relationship to a unit of measure used for calibration of measuring devices * Standard (timber unit), an obsolete measure of timber used in trade * Breed standard (also called bench standard), in animal fancy and animal husbandry * BioCompute Standard, a standard for next generation sequencing * ''De facto'' standard, product or system with market dominance * Gold standard, a monetary system based on gold; also used metaphorically for the best of several options, against which the others are measured * Internet Standard, a specification ratified as an open standard by the Internet Engineering Task Force * Learning standards, standards applied to education content * Standard displacement, a naval term describing th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Input
In computer programming, standard streams are preconnected input and output communication channels between a computer program and its environment when it begins execution. The three input/output (I/O) connections are called standard input (stdin), standard output (stdout) and standard error (stderr). Originally I/O happened via a physically connected system console (input via keyboard, output via monitor), but standard streams abstract this. When a command is executed via an interactive shell, the streams are typically connected to the text terminal on which the shell is running, but can be changed with redirection or a pipeline. More generally, a child process inherits the standard streams of its parent process. Application Users generally know standard streams as input and output channels that handle data coming from an input device, or that write data from the application. The data may be text with any encoding, or binary data. When a program is run as a daemon, its standard ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
