A Hierarchical Shadow Volume Algorithm
(2004) p.15-23- Abstract
- The shadow volume algorithm is a popular technique for real-time shadow generation using graphics hardware.
Its major disadvantage is that it is inherently fillrate-limited, as the performance is inversely proportional to the area of the projected shadow volumes. We present a new algorithm that reduces the shadow volume rasterization
work significantly. With our algorithm, the amount of per-pixel processing becomes proportional to the screenspace
length of the visible shadow boundary instead of the projected area. The first stage of the algorithm finds
8×8 pixel tiles, whose 3D bounding boxes are either completely inside or outside the shadow volume. After that, the second stage performs per-pixel... (More) - The shadow volume algorithm is a popular technique for real-time shadow generation using graphics hardware.
Its major disadvantage is that it is inherently fillrate-limited, as the performance is inversely proportional to the area of the projected shadow volumes. We present a new algorithm that reduces the shadow volume rasterization
work significantly. With our algorithm, the amount of per-pixel processing becomes proportional to the screenspace
length of the visible shadow boundary instead of the projected area. The first stage of the algorithm finds
8×8 pixel tiles, whose 3D bounding boxes are either completely inside or outside the shadow volume. After that, the second stage performs per-pixel computations only for the potential shadow boundary tiles. We outline a twopass implementation, and also describe an efficient single-pass hardware architecture, in which the two stages are separated using a delay stream. The only modification required in applications is a new pair of calls for marking the beginning and end of a shadow volume. In our test scenes, the algorithm processes up to 11.5 times fewer pixels compared to current state-of-the-art methods, while reducing the external video memory bandwidth by a factor of up to 17.1. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/746946
- author
- Aila, Timo and Akenine-Möller, Tomas LU
- organization
- publishing date
- 2004
- type
- Chapter in Book/Report/Conference proceeding
- publication status
- published
- subject
- host publication
- Graphics Hardware
- pages
- 15 - 23
- publisher
- Eurographics - European Association for Computer Graphics
- external identifiers
-
- scopus:29244452672
- ISBN
- 3905673150
- language
- English
- LU publication?
- yes
- id
- cb018985-38ae-49c9-ac33-1b33e52910e1 (old id 746946)
- date added to LUP
- 2016-04-04 10:59:31
- date last changed
- 2022-02-06 06:37:49
@inproceedings{cb018985-38ae-49c9-ac33-1b33e52910e1,
abstract = {{The shadow volume algorithm is a popular technique for real-time shadow generation using graphics hardware.<br/><br>
Its major disadvantage is that it is inherently fillrate-limited, as the performance is inversely proportional to the area of the projected shadow volumes. We present a new algorithm that reduces the shadow volume rasterization<br/><br>
work significantly. With our algorithm, the amount of per-pixel processing becomes proportional to the screenspace<br/><br>
length of the visible shadow boundary instead of the projected area. The first stage of the algorithm finds<br/><br>
8×8 pixel tiles, whose 3D bounding boxes are either completely inside or outside the shadow volume. After that, the second stage performs per-pixel computations only for the potential shadow boundary tiles. We outline a twopass implementation, and also describe an efficient single-pass hardware architecture, in which the two stages are separated using a delay stream. The only modification required in applications is a new pair of calls for marking the beginning and end of a shadow volume. In our test scenes, the algorithm processes up to 11.5 times fewer pixels compared to current state-of-the-art methods, while reducing the external video memory bandwidth by a factor of up to 17.1.}},
author = {{Aila, Timo and Akenine-Möller, Tomas}},
booktitle = {{Graphics Hardware}},
isbn = {{3905673150}},
language = {{eng}},
pages = {{15--23}},
publisher = {{Eurographics - European Association for Computer Graphics}},
title = {{A Hierarchical Shadow Volume Algorithm}},
year = {{2004}},
}