Search results
Results from the WOW.Com Content Network
Thermal radiation is the emission of electromagnetic waves from all matter that has a temperature greater than absolute zero. [5] [2] Thermal radiation reflects the conversion of thermal energy into electromagnetic energy. Thermal energy is the kinetic energy of random movements of atoms and molecules in matter.
Rendering equation. In computer graphics, the rendering equation is an integral equation in which the equilibrium radiance leaving a point is given as the sum of emitted plus reflected radiance under a geometric optics approximation. It was simultaneously introduced into computer graphics by David Immel et al. [1] and James Kajiya [2] in 1986.
View factor. In radiative heat transfer, a view factor, , is the proportion of the radiation which leaves surface that strikes surface . In a complex 'scene' there can be any number of different objects, which can be divided in turn into even more surfaces and surface segments. View factors are also sometimes known as configuration factors ...
Radiant flux emitted, reflected, transmitted or received by a surface, per unit solid angle per unit projected area. This is a directional quantity. This is sometimes also confusingly called "intensity". Radiance of a surface per unit frequency or wavelength. The latter is commonly measured in W⋅sr −1 ⋅m −2 ⋅nm −1.
Black-body radiation. Black-body radiation is the thermal electromagnetic radiation within, or surrounding, a body in thermodynamic equilibrium with its environment, emitted by a black body (an idealized opaque, non-reflective body). It has a specific, continuous spectrum of wavelengths, inversely related to intensity, that depend only on the ...
Gebhart factor. The Gebhart factors are used in radiative heat transfer, it is a means to describe the ratio of radiation absorbed by any other surface versus the total emitted radiation from given surface. As such, it becomes the radiation exchange factor between a number of surfaces.
The relationship between thermal conductance and resistance is analogous to that between electrical conductance and resistance in the domain of electronics. Thermal insulance ( R -value) is a measure of a material's resistance to the heat current. It quantifies how effectively a material can resist the transfer of heat through conduction ...
Radiometry is a set of techniques for measuring electromagnetic radiation, including visible light. Radiometric techniques in optics characterize the distribution of the radiation's power in space, as opposed to photometric techniques, which characterize the light's interaction with the human eye. The fundamental difference between radiometry ...