Antialiased shadow algorithms for game rendering

Authors:
Nailiang Zhao;Yanjun Chen;Zhigeng Pan
Affiliations:
College of Computer Science, Hangzhou Dianzi University, Hangzhou, Zhejiang, P.R. China;College of Computer Science, Hangzhou Dianzi University, Hangzhou, Zhejiang, P.R. China;State Key Laboratory of CAD&CG, Zhejiang University, Hangzhou, Zhejiang, P.R. China
Venue:
Edutainment'06 Proceedings of the First international conference on Technologies for E-Learning and Digital Entertainment
Year:
2006

Citing 9
Cited 0

Rendering antialiased shadows with depth maps

SIGGRAPH '87 Proceedings of the 14th annual conference on Computer graphics and interactive techniques
Deep shadow maps

Proceedings of the 27th annual conference on Computer graphics and interactive techniques
Adaptive shadow maps

Proceedings of the 28th annual conference on Computer graphics and interactive techniques
Perspective shadow maps

Proceedings of the 29th annual conference on Computer graphics and interactive techniques
Hardware-Accelerated Rendering of Antialiased Shadows with Shadow Maps

CGI '01 Computer Graphics International 2001
Casting curved shadows on curved surfaces

SIGGRAPH '78 Proceedings of the 5th annual conference on Computer graphics and interactive techniques
Shadow silhouette maps

ACM SIGGRAPH 2003 Papers
Penumbra maps: approximate soft shadows in real-time

EGRW '03 Proceedings of the 14th Eurographics workshop on Rendering
Rendering fake soft shadows with smoothies

EGRW '03 Proceedings of the 14th Eurographics workshop on Rendering

Quantified Score

Hi-index	0.00

Visualization

Abstract

Shadow maps provide a fast and convenient method of generating real-time shadows in computer games. Unfortunately, shadow maps suffer from aliasing problems. Percentage Closer Filtering (PCF) is one of the solutions, but in cases of severe aliasing it can only mask the aliasing by unnaturally blurring. In this paper we present two improved antialiased shadow algorithms based on PCF, named as Modified PCF I and Modified PCF II. The primary idea of our algorithms is to make sawtooth shadow edges straighter just by data modification before bilinear interpolation in PCF. We respectively implement the algorithms with graphic hardware in Pixel Shader 2.0 and 3.0, several examples are also provided to show that most of aliasing artifacts have been removed compared with PCF. The time complexity and hardware requirement of Modified PCF I are almost as same as that of PCF. The resource requirement of Modified PCF II is more rigorous than that of Modified PCF I, but it can still accommodate to real-time game rendering with obvious antialiasing effect.