TY - GEN

T1 - Partitioning and ordering large radiosity computations

AU - Teller, Seth

AU - Fowler, Celeste

AU - Funkhouser, Thomas

AU - Hanrahan, Pat

N1 - Funding Information:
We are grateful to the National Science Foundation (contract No. CCR 9207966) and to DIMACS for their support, and to Silicon Graphics, Forest Baskett, and Jim Clark for their gift of a Reality Engine.tm
Publisher Copyright:
© ACM 1994.

PY - 1994/7/24

Y1 - 1994/7/24

N2 - We describe a system that computes radiosity solutions for polygonal environments much larger than can be stored in main memory. The solution is stored in and retrieved from a database as the computation proceeds. Our system is based on two ideas: the use of visibility oracles to find source and blocker surfaces potentially visible to a receiving surface; and the use of hierarchical techniques to represent interactions between large surfaces efficiently, and to represent the computed radiosity solution compactly. Visibility information allows the environment to be partitioned into subsets, each containing all the information necessary to transfer light to a cluster of receiving polygons. Since the largest subset needed for any particular cluster is much smaller than the total size of the environment, these subset computations can be performed in much less memory than can classical or hierarchical radiosity. The computation is then ordered for further efficiency. Careful ordering of energy transfers minimizes the number of database reads and writes. We report results from large solutions of unfurnished and furnished buildings, and show that our implementation's observed running time scales nearly linearly with both local and global model complexity.

AB - We describe a system that computes radiosity solutions for polygonal environments much larger than can be stored in main memory. The solution is stored in and retrieved from a database as the computation proceeds. Our system is based on two ideas: the use of visibility oracles to find source and blocker surfaces potentially visible to a receiving surface; and the use of hierarchical techniques to represent interactions between large surfaces efficiently, and to represent the computed radiosity solution compactly. Visibility information allows the environment to be partitioned into subsets, each containing all the information necessary to transfer light to a cluster of receiving polygons. Since the largest subset needed for any particular cluster is much smaller than the total size of the environment, these subset computations can be performed in much less memory than can classical or hierarchical radiosity. The computation is then ordered for further efficiency. Careful ordering of energy transfers minimizes the number of database reads and writes. We report results from large solutions of unfurnished and furnished buildings, and show that our implementation's observed running time scales nearly linearly with both local and global model complexity.

KW - Equilibrium methods

KW - Multigridding

KW - Spatial subdivision

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U2 - 10.1145/192161.192279

DO - 10.1145/192161.192279

M3 - Conference contribution

AN - SCOPUS:85022121644

T3 - Proceedings of the 21st Annual Conference on Computer Graphics and Interactive Techniques, SIGGRAPH 1994

SP - 443

EP - 450

BT - Proceedings of the 21st Annual Conference on Computer Graphics and Interactive Techniques, SIGGRAPH 1994

PB - Association for Computing Machinery, Inc

T2 - 21st Annual Conference on Computer Graphics and Interactive Techniques, SIGGRAPH 1994

Y2 - 24 July 1994 through 29 July 1994

ER -