Articles Tagged: Information theory
Articles & Features
Don't ask me
Searching for information online has become an integral part of our everyday lives. However, sometimes we don't know the specific search terms to use, while other times, the specific information we're seeking hasn't been recorded online yet.
By Gary Hsieh, December 2009
Introduction
By Justin Solomon, December 2008
Detecting steganography on a large scale
By William Ella, December 2008
Introduction
By Justin Solomon, September 2008
Geometric and path tracing methods for simulating light transport through volumes of water particles
The visual appearance of volumes of water particles, such as clouds, waterfalls, and fog, depends both on microscopic interactions between light rays and individual droplets of water, and also on macroscopic interactions between multiple droplets and paths of light rays. This paper presents a model that builds upon a typical single-scattering volume renderer to correctly account for these effects. To accurately simulate the visual appearance of a surface or a volume of particles in a computer-generated image, the properties of the material or particle must be specified using a Bidirectional Reflectance Distribution Function (BRDF), which describes how light reflects off of a material, and the Bidirectional Transmittance Distribution Function (BTDF), which describes how light refracts into a material. This paper describes an optimized BRDF and BTDF for volumes of water droplets, which takes their geometry into account in order to produce well-known effects, such as rainbows and halos. It also describes how a multiple-scattering path tracing volume integrator can be used to more accurately simulate macroscopic light transport through a volume of water, creating a more "cloudlike" appearance than a single-scattered volume integrator. This paper focuses on replicating the visual appearance of volumes of water particles, and although it makes use of physical models, the techniques presented are not intended to be physically accurate.
By James Hegarty, September 2008
Data encryption
By Ed DeHart, September 2008
Introduction
By William Stevenson, May 2005
In memory of David Huffman
By Kevin Fu, March 2000