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Hierarchical Image‐Space Radiosity for Interactive Global Illumination
Author(s) -
Nichols Greg,
Shopf Jeremy,
Wyman Chris
Publication year - 2009
Publication title -
computer graphics forum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.578
H-Index - 120
eISSN - 1467-8659
pISSN - 0167-7055
DOI - 10.1111/j.1467-8659.2009.01491.x
Subject(s) - global illumination , radiosity (computer graphics) , computer science , computation , computer vision , computer graphics (images) , artificial intelligence , shadow (psychology) , preprocessor , cluster analysis , object (grammar) , image (mathematics) , pixel , point (geometry) , computer graphics , graphics hardware , shadow mapping , frustum , algorithm , rendering (computer graphics) , mathematics , psychology , geometry , psychotherapist
We introduce image‐space radiosity and a hierarchical variant as a method for interactively approximating diffuse indirect illumination in fully dynamic scenes. As oft observed, diffuse indirect illumination contains mainly low‐frequency details that do not require independent computations at every pixel. Prior work leverages this to reduce computation costs by clustering and caching samples in world or object space. This often involves scene preprocessing, complex data structures for caching, or wasted computations outside the view frustum. We instead propose clustering computations in image space, allowing the use of cheap hardware mipmapping and implicit quadtrees to allow coarser illumination computations. We build on a recently introduced multiresolution splatting technique combined with an image‐space lightcut algorithm to intelligently choose virtual point lights for an interactive, one‐bounce instant radiosity solution. Intelligently selecting point lights from our reflective shadow map enables temporally coherent illumination similar to results using more than 4096 regularly‐sampled VPLs.