Results 1 
4 of
4
A rapid hierarchical radiosity algorithm
 Computer Graphics
, 1991
"... This paper presents a rapid hierarchical radiosity algorithm for illuminating scenes containing lar e polygonal patches. The afgorithm constructs a hierarchic“J representation of the form factor matrix by adaptively subdividing patches into su bpatches according to a usersupplied error bound. The a ..."
Abstract

Cited by 369 (11 self)
 Add to MetaCart
This paper presents a rapid hierarchical radiosity algorithm for illuminating scenes containing lar e polygonal patches. The afgorithm constructs a hierarchic“J representation of the form factor matrix by adaptively subdividing patches into su bpatches according to a usersupplied error bound. The algorithm guarantees that all form factors are calculated to the same precision, removing many common image artifacts due to inaccurate form factors. More importantly, the al orithm decomposes the form factor matrix into at most O? n) blocks (where n is the number of elements). Previous radiosity algorithms represented the elementtoelement transport interactions with n2 form factors. Visibility algorithms are given that work well with this approach. Standard techniques for shooting and gathering can be used with the hierarchical representation to solve for equilibrium radiosities, but we also discuss using a brightnessweighted error criteria, in conjunction with multigrldding, to even more rapidly progressively refine the image.
A hierarchical illumination algorithm for surfaces with glossy reflection
 In SIGGRAPH 93
, 1993
"... We develop a radiance formulation for discrete three point transport, and a new measure and description of reflectance:area reflectance. This formulation and associated reflectance allow an estimate of error in the computation of radiance across triples of surface elements, and lead directly to a hi ..."
Abstract

Cited by 59 (3 self)
 Add to MetaCart
We develop a radiance formulation for discrete three point transport, and a new measure and description of reflectance:area reflectance. This formulation and associated reflectance allow an estimate of error in the computation of radiance across triples of surface elements, and lead directly to a hierarchical refinement algorithm for global illumination. We have implemented and analyzed this algorithm over surfaces exhibiting glossy specular and diffuse reflection. Theoretical growth in light transport computation is shown to beO(n+k 3) for sufficient refinement, where n is the number of elements at the finest level of subdivision over an environment consisting ofk input polygonal patches — this growth is exhibited in experimental trials. Naive application of three point transport would require computation over O(n 3) elementtriple interactions.
A Rapid Hierachical Radiosity Algorithm
, 1991
"... This paper presents a rapid hierarchical radiosity algorithm for illuminating scenes containing large polygonal patches. The algorithm constructs a hierarchical representation of the form factor matrix by adaptively subdividing patches into subpatches according to a usersupplied error bound. The al ..."
Abstract

Cited by 10 (0 self)
 Add to MetaCart
This paper presents a rapid hierarchical radiosity algorithm for illuminating scenes containing large polygonal patches. The algorithm constructs a hierarchical representation of the form factor matrix by adaptively subdividing patches into subpatches according to a usersupplied error bound. The algorithm guarantees that all form factors are calculated to the same precision, removing many common image artifacts due to inaccurate form factors. More importantly, the algorithm decomposes the form factor matrix into at most O(n) blocks (where n is the number of elements). Previous radiosity algorithms represented the elementtoelement transport interactions with n 2 form factors. Visibility algorithms are given that work well with this approach. Standard techniques for shooting and gathering can be used with the hierarchical representation to solve for equilibrium radiosities, but we also discuss using a brightnessweighted error criteria, in conjunction with multigridding, to even mor...
Hierarchical Algorithms For Illumination
, 1993
"... This dissertation is a discussion and development of hierarchical algorithms for illumination. These algorithms operate through recursive, adaptive refinement of the environment into hierarchical meshes  rather than computing light transport only between elements at the finest level of refinement ..."
Abstract

Cited by 10 (1 self)
 Add to MetaCart
This dissertation is a discussion and development of hierarchical algorithms for illumination. These algorithms operate through recursive, adaptive refinement of the environment into hierarchical meshes  rather than computing light transport only between elements at the finest level of refinement, the algorithms allow computation of transport between higher level subpatches, as controlled by user specified error bounds. As discussed in this dissertation, employment of hierarchical methods yields significant savings in computation. The initial work in hierarchical methods was that of Hanrahan and Salzman for the computation of radiosity over unoccluded environments. In this dissertation, we discuss extension of the algorithm to occluded environments, incorporating visibility heuristics and acceleration via radiosity weighting. Given an environment consisting of k polygonal patches and n elements at the finest level of refinement, the algorithm requires at most O(n + k 2 ) transpor...