The incident indirect light over a range of image pixels is often coherent. Two common approaches to exploit this inter-pixel coherence to improve rendering performance are Irradiance Caching and Radiance Caching. Both compute incident indirect light only for a small subset of pixels (the cache), and later interpolate between pixels. Irradiance Caching uses scalar values that can be interpolate...

A primary impact of urbanization on the local climate is evident in the phenomenon recognized as the Urban Heat Island (UHI) effect. This urban thermal anomaly can increase the health risks of vulnerable populations to heat waves. The surface UHI results from emittance in the longer wavelengths of the thermal infrared; however, there are also urban anomalies that are detectable from radiance in...

Architectural walkthroughs require fast global illumination algorithms and also accurate results from certain viewpoints. This paper introduces a global illumination method that combines several strategies to meet the contradicting criteria of architectural walkthroughs. The methods include parallel and perspective ray-bundle shooting and ray shooting. Each method is designed to randomly approx...

Three southern USA forestry species, loblolly pine (Pinus taeda), Virginia pine (Pinus virginiana), and shortleaf pine (Pinus echinata), were previously shown to be spectrally separable (83% accuracy) using data from a full-range spectroradiometer (400–2500 nm) acquired above tree canopies. This study focused on whether these same species are also separable using hyperspectral data acquired usi...

A high current hollow cathode source has been developed as a radiometric source standard for the extreme VUV. The source is operated at a constant current of 2 A with an aluminum cathode and helium or argon as buffer gas at pressures of ~1 hPa. The radiance of spectral lines in the wavelength range from 13 to 60 nm has been determined by comparison to the calculable spectral radiant power of th...

This work is based on measurements made at the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) central facility from April through June 1997. Five instruments of the ARM SGP central facility have principal roles in this study. The millimeter wave cloud radar (MMCR) is used to measure N and β. The microwave radiometer (MWR) is used to determine when water clouds are overhead;...

There has been great success in speeding up global illumination computation in diffuse environments. The concept of clustering allows radiosity computations even for scenes of high complexity. However, for lighting simulations in complex non-diffuse scenes, Monte-Carlo sampling methods are currently the first choice, because non-diffuse finite-element approaches still exhibit enormous computati...