Hidden-surface determinationIn 3D computer graphics, hidden-surface determination (also known as shown-surface determination, hidden-surface removal (HSR), occlusion culling (OC) or visible-surface determination (VSD)) is the process of identifying what surfaces and parts of surfaces can be seen from a particular viewing angle. A hidden-surface determination algorithm is a solution to the visibility problem, which was one of the first major problems in the field of 3D computer graphics .
Render output unitIn computer graphics, the render output unit (ROP) or raster operations pipeline is a hardware component in modern graphics processing units (GPUs) and one of the final steps in the rendering process of modern graphics cards. The pixel pipelines take pixel (each pixel is a dimensionless point) and texel information and process it, via specific matrix and vector operations, into a final pixel or depth value; this process is called rasterization. Thus, ROPs control antialiasing, when more than one sample is merged into one pixel.
Virtual actorA virtual human, virtual persona, or digital clone is the creation or re-creation of a human being in image and voice using and sound, that is often indistinguishable from the real actor. The idea of a virtual actor was first portrayed in the 1981 film Looker, wherein models had their bodies scanned digitally to create 3D computer generated images of the models, and then animating said images for use in TV commercials. Two 1992 books used this concept: Fools by Pat Cadigan, and Et Tu, Babe by Mark Leyner.
Change of variablesIn mathematics, a change of variables is a basic technique used to simplify problems in which the original variables are replaced with functions of other variables. The intent is that when expressed in new variables, the problem may become simpler, or equivalent to a better understood problem. Change of variables is an operation that is related to substitution. However these are different operations, as can be seen when considering differentiation (chain rule) or integration (integration by substitution).
Notation for differentiationIn differential calculus, there is no single uniform notation for differentiation. Instead, various notations for the derivative of a function or variable have been proposed by various mathematicians. The usefulness of each notation varies with the context, and it is sometimes advantageous to use more than one notation in a given context. The most common notations for differentiation (and its opposite operation, the antidifferentiation or indefinite integration) are listed below.
Differential calculusIn mathematics, differential calculus is a subfield of calculus that studies the rates at which quantities change. It is one of the two traditional divisions of calculus, the other being integral calculus—the study of the area beneath a curve. The primary objects of study in differential calculus are the derivative of a function, related notions such as the differential, and their applications. The derivative of a function at a chosen input value describes the rate of change of the function near that input value.
