Title
Fast global illumination on dynamic height fields
Abstract
We present a real-time method for rendering global illumination effects from large area and environmental lights on dynamic height fields. In contrast to previous work, our method handles inter-reflections (indirect lighting) and non-diffuse surfaces. To reduce sampling, we construct one multi-resolution pyramid for height variation to compute direct shadows, and another pyramid for each indirect bounce of incident radiance to compute interreflections. The basic principle is to sample the points blocking direct light, or shedding indirect light, from coarser levels of the pyramid the farther away they are from a given receiver point. We unify the representation of visibility and indirect radiance at discrete azimuthal directions (i.e., as a function of a single elevation angle) using the concept of a "casting set" of visible points along this direction whose contributions are collected in the basis of normalized Legendre polynomials. This analytic representation is compact, requires no precomputation, and allows efficient integration to produce the spherical visibility and indirect radiance signals. Sub-sampling visibility and indirect radiance, while shading with full-resolution surface normals, further increases performance without introducing noticeable artifacts. Our method renders 512x512 height fields ( 500K triangles) at 36Hz.
Year
DOI
Venue
2009
10.1111/j.1467-8659.2009.01490.x
Comput. Graph. Forum
Keywords
Field
DocType
height field,indirect radiance,indirect lighting,indirect bounce,incident radiance,indirect radiance signal,dynamic height field,height variation,global illumination,sub-sampling visibility,indirect light,real time,legendre polynomial,shading
Computer vision,Visibility,Precomputation,Computer science,Legendre polynomials,Azimuth,Pyramid,Artificial intelligence,Global illumination,Radiance,Dynamic height
Journal
Volume
Issue
ISSN
28
4
0167-7055
Citations 
PageRank 
References 
11
0.53
23
Authors
2
Name
Order
Citations
PageRank
Derek Nowrouzezahrai180154.49
John Snyder22579172.17