Articles
2002 -
Antialiasing
When a primitive is drawn grid cells are replaced with the primitive's colour or left unchanged. Its edges are jagged because of this all-or-nothing approach of filling in grid cells. Aliasing is a term used to describe the jagged appearance. The application of methods to reduce aliasing is known as antialiasing.

Tessellation
Display hardware is optimised to process and draw triangles. A surface is tessleated into these simple shapes before display.

Patches
More than one patch is often required to adaquately describe the complexities of an object. This piece-wise approach has several benefits, one of which is the ability to stitch together simple patches that are easy to manipulate and fast to draw.

Outdoor Lighting
A photon is a quantum of electromagnetic energy. We perceive this energy as visible light if its wavelength falls within the range of four thousand (violet) to eight thousand (red) angstroms. To simulate an outdoor environment we often use the Sun as the light source.

Indoor Lighting
Most indoor environments are illuminated by more than one light source. The energy transfers that occur require detailed calculations. For every instance of light bouncing off an object we need to determine how much of the light is absorbed and to where it travels next.

Haar Wavelets
Wavelets are used to represent functions in an elegant manner. The function can be an image, curve or surface. With its initial use in approximation theory and signal processing, wavelets can also be applied to image editing, global illumination and radiosity.

Catmull-Clark Surfaces
Almost three decades ago, Chaikin introduced an ingenious method for generating curves. The algorithm was a corner cutting or refinement scheme that produced a smooth curve from a given control polygon. In the following years, many subdivision schemes for modeling smooth objects have been developed based on Chaikin's pioneering endeavour.

Liang-Barsky Line Clipping
Almost two decades ago, Liang and Barsky developed a fast and efficient parametric line clipping algorithm where the clip region is an upright rectangle.

Watercolour
Nonphotorealistic techniques have become an increasingly popular topic in research circles. These methods provide a stylistic approach to draw images.

"Square Root Three" Subdivision
Powerful computer hardware and clever algorithms are two reasons for the growing popularity of subdivision schemes in the efficient generation of freeform surfaces. Such methods are simple, robust and have many practical applications.

The Rendering Equation
Visual detail is often conveyed using clever lighting algorithms to simulate a variety of physical properties. The basis of these techniques lies in estimating the amount of light energy being transmitted, reflected or absorbed at a given location. All such methods are derived from the rendering equation, a very important contribution to the field of computer graphics by James T. Kajiya.

Nonphotorealistic Rendering
Cel shading is a common nonphotorealistic rendering (NPR) technique. Objects are drawn using a very limited colour palatte. Transitions in colour are often abrupt so roundness is implied.

Computer Image File Formats
Motion picture films have become increasing subject to digital manipulation. Old films, for example, are restored to their original luster when artists remove blemishes and other visual artifacts. Colours may be changed and even new objects or characters are added to scenes. Computer image file formats must be able to represent even the most subtle shifts in hue and saturation.

Outdoor Lighting Revisited
Methods to illuminate an outdoor scene during the daytime hours is well documented. Less attention has been devoted to accurately depict nighttime outdoor environments.

High Dynamic Range Rendering
Current display devices have a limited gamut of intensities. Our eyes, however, are much more sensitive by several orders of magnitude. To better mimic how we perceive colour in the real-world we use high dynamic range (HDR) rendering.

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