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Proceedings ArticleDOI

Variance shadow maps

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TLDR
This paper introduces variance shadow maps, a new real time shadowing algorithm that stores the mean and mean squared of a distribution of depths, from which it can efficiently compute the variance over any filter region.
Abstract
Shadow maps are a widely used shadowing technique in real time graphics. One major drawback of their use is that they cannot be filtered in the same way as color textures, typically leading to severe aliasing. This paper introduces variance shadow maps, a new real time shadowing algorithm. Instead of storing a single depth value, we store the mean and mean squared of a distribution of depths, from which we can efficiently compute the variance over any filter region. Using the variance, we derive an upper bound on the fraction of a shaded fragment that is occluded. We show that this bound often provides a good approximation to the true occlusion, and can be used as an approximate value for rendering. Our algorithm is simple to implement on current graphics processors and solves the problem of shadow map aliasing with minimal additional storage and computation.

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Citations
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Proceedings ArticleDOI

Finding next gen: CryEngine 2

TL;DR: The work presented here takes significant advantage of research done by the graphics community in recent years and combines it with novel ideas developed within Crytek to realize implementations that efficiently map onto graphics hardware.
Proceedings ArticleDOI

Convolution shadow maps

TL;DR: Convolution Shadow Maps is presented, a novel shadow representation that affords efficient arbitrary linear filtering of shadows, and it is shown that hardware-accelerated anti-aliasing techniques, such as tri-linear filtering, can be applied naturally to Convolution shadow Maps.
Journal ArticleDOI

Real-time, all-frequency shadows in dynamic scenes

TL;DR: This paper presents a technique for rendering dynamic objects under arbitrary environment illumination, which does not require any precomputation and achieves several hundred frames per second for a single light source and yields real-time frame rates.
Journal ArticleDOI

Global illumination with radiance regression functions

TL;DR: The approach is to exploit the nonlinear coherence of the indirect illumination data to make the RRF both compact and fast to evaluate, which enables real-time rendering with full global illumination effects, including changing caustics and multiple-bounce high-frequency glossy interreflections.
Journal ArticleDOI

High resolution sparse voxel DAGs

TL;DR: This work presents an efficient bottom-up algorithm that reduces an SVO to a minimal DAG, which can be applied even in cases where the complete SVO would not fit in memory, and demonstrates this by ray tracing hard and soft shadows, ambient occlusion, and primary rays in extremely high resolution DAGs at speeds that are on par with, or even faster than, state-of-the-art voxel and triangle GPU ray tracing.
References
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Proceedings ArticleDOI

Summed-area tables for texture mapping

TL;DR: Texture-map computations can be made tractable through use of precalculated tables which allow computational costs independent of the texture density, and the cost and performance of the new technique is compared to previous techniques.
Proceedings ArticleDOI

Pyramidal parametrics

TL;DR: This paper advances a “pyramidal parametric” prefiltering and sampling geometry which minimizes aliasing effects and assures continuity within and between target images.
Book

Casting curved shadows on curved surfaces

TL;DR: A simple algorithm is described which utilizes Z-buffer visible surface computation to display shadows cast by objects modelled of smooth surface patches, and is contrasted with a less costly method for casting the shadows of the environment on a single ground plane.
Proceedings ArticleDOI

Casting curved shadows on curved surfaces

TL;DR: In this article, a simple algorithm is described which utilizes Z-buffer visible surface computation to display shadows cast by objects modelled of smooth surface patches, which can be applied to all environments, in fact, for which visible surfaces can be computed.
Proceedings ArticleDOI

Shadow algorithms for computer graphics

TL;DR: A classification of shadow algorithms delineates three approaches: shadow computation during scanout; division of object surfaces into shadowed and unshadowed areas prior to removal of hidden surfaces; and inclusion of shadow volumes in the object data.