GPU Pro 360 Guide to Shadows

Wolfgang Engel

• Publisher: A K Peters/CRC Press
• Year: 2018
• ISBN:
  9781351208338
• Edition: 1
• Topic: Computer Science
• Subtopic: Computer Science General
• Index: Computer Science

Wolfgang Engel's GPU Pro 360 Guide to Shadows gathers all the cutting-edge information from his previous seven GPU Pro volumes into a convenient single source anthology that covers various algorithms that are used to generate shadow data. This volume is complete with 15 articles by leading programmers that focus on achieving good visual results in rendering shadows. GPU Pro 360 Guide to Shadows is comprised of ready-to-use ideas and efficient procedures that can help solve many computer graphics programming challenges that may arise.

Key Features:

• Presents tips & tricks on real-time rendering of special effects and visualization data on common consumer software platforms such as PCs, video consoles, mobile devices

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• Covers specific challenges involved in creating games on various platforms

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• Explores the latest developments in rapidly evolving field of real-time rendering

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• Takes practical approach that helps graphics programmers solve their daily challenges

Contents

Introduction

Web Materials

1 Fast Conventional Shadow Filtering

Holger Gruen

1.1 Overview

1.2 Introduction

1.3 Uniform Shadow Filtering

1.4 Separable Shadow Filters

1.5 Nonseparable Unique Weights per PCF Result

1.6 Advanced Shadow Filtering Techniques

Bibliography

2 Hybrid Min/Max Plane-Based Shadow Maps

Holger Gruen

2.1 Overview

2.2 Introduction

2.3 Construction of an HPSM

2.4 Using an HPSM

2.5 Other Uses for the HPSM

Bibliography

3 Shadow Mapping for Omnidirectional Light Using Tetrahedron Mapping

Hung-Chien Liao

3.1 Shadow Mapping

3.2 Tetrahedron Shadow Mapping

3.3 Optimization

3.4 Lookup Map

3.5 Conclusion

Bibliography

4 Screen Space Soft Shadows

Jesus Gumbau, Miguel Chover, and Mateu Sbert

4.1 Introduction

4.2 Previous Work

4.3 Screen Space Soft Shadows

4.4 Results

4.5 Conclusion

Bibliography

5 Variance Shadow Maps Light-Bleeding Reduction Tricks

Wojciech Sterna

5.1 Introduction

5.2 VSM Overview

5.3 Light-Bleeding

5.4 Solutions to the Problem

5.5 Sample Application

5.6 Conclusion

Bibliography

6 Fast Soft Shadows via Adaptive Shadow Maps

Pavlo Turchyn

6.1 Percentage-Closer Filtering with Large Kernels

6.2 Application to Adaptive Shadow Maps

6.3 Soft Shadows with Variable Penumbra Size

6.4 Results

Bibliography

7 Adaptive Volumetric Shadow Maps

Marco Salvi, Kiril Vidimče, Andrew Lauritzen, Aaron Lefohn and Matt Pharr

7.1 Introduction and Previous Approaches

7.2 Algorithm and Implementation

7.3 Comparisons

7.4 Conclusions and Future Work

7.5 Acknowledgments

Bibliography

8 Fast Soft Shadows with Temporal Coherence

Daniel Scherzer, Michael Schwärzler and Oliver Mattausch

8.1 Introduction

8.2 Algorithm

8.3 Comparison and Results

Bibliography

9 Mipmapped Screen-Space Soft Shadows

Alberto Aguado and Eugenia Montiel

9.1 Introduction and Previous Work

9.2 Penumbra Width

9.3 Screen-Space Filter

9.4 Filtering Shadows

9.5 Mipmap Level Selection

9.6 Multiple Occlusions

9.7 Discussion

Bibliography

10 Efficient Online Visibility for Shadow Maps

Oliver Mattausch, Jiri Bittner, Ari Silvennoinen, Daniel Scherzer and Michael Wimmer

10.1 Introduction

10.2 Algorithm Overview

10.3 Detailed Description

10.4 Optimization: Shadow-Map Focusing

10.5 Results

10.6 Conclusion

10.7 Acknowledgments

Bibliography

11 Depth Rejected Gobo Shadows

John White

11.1 Introduction

11.2 Basic Gobo Shadows

11.3 Depth Rejected Gobo Shadows

11.4 Extensions

11.5 Failure Case

Bibliography

12 Real-Time Deep Shadow Maps

René Fürst, Oliver Mattausch and Daniel Scherzer

12.1 Introduction

12.2 Transmittance Function

12.3 Algorithm

12.4 Results

12.5 Conclusions

12.6 Acknowledgments

Bibliography

13 Practical Screen-Space Soft Shadows

Márton Tamás and Viktor Heisenberger

13.1 Introduction

13.2 Overview

13.3 History

13.4 Algorithm Overview

13.5 Shadow Map Rendering Pass

13.6 Introducing Layers and Light Assignment

13.7 Layered Penumbra Map Pass

13.8 Anisotropic Gaussian Blur Pass

13.9 Lighting Pass

13.10 Performance Considerations

13.11 Results

13.12 Quality Tests

13.13 Performance Analysis

13.14 Conclusion

Bibliography

14 Tile-Based Omnidirectional Shadows

Hawar Doghramachi

14.1 Introduction

14.2 Overview

14.3 Implementation

14.4 Results

14.5 Discussion

14.6 Conclusion

14.7 Acknowledgments

Bibliography

15 Shadow Map Silhouette Revectorization

Vladimir Bondarev

15.1 Introduction

15.2 Implementation

15.3 Results

15.4 Future Work

15.5 Conclusion

Bibliography

About the Contributors

Introduction

In this book we cover various algorithms that are used to generate shadow data. Shadows are the dark companion of lights and although both can exist on their own, they shouldn’t exist without each other in games. Achieving good visual results in rendering shadows is still considered one of the particularly difficult tasks of graphics programmers.

The chapter “Fast Conventional Shadow Filtering,” by Holger Gruen, covers an algorithm that can be used to reduce the number of necessary percentage closer filtering (PCF) texture operations roughly to a third. This allows the usage of larger filter kernels and therefore results in a softer penumbra that is necessary to reduce the perspective aliasing of shadow pixels along the view frustum.

Holger Gruen’s second chapter has a similar target. In “Hybrid Min/Max Plane-Based Shadow Maps,” he shows a way to derive a secondary texture from a normal depth-only shadow map that can be used to speed up expensive shadow filtering kernels. He stores a plane equation or min/max depth data for a block of pixels of the original shadow map. Both techniques are especially tailored to rendering shadows on the upcoming generation of graphics hardware.

Hung-Chien Liao demonstrates in his chapter “Shadow Mapping for Omnidirectional Light Using Tetrahedron Mapping” a new way to store shadow data. Instead of using a cube or dual-paraboloid map, he proposes using a tetrahedron projection and storing the data in a two-dimensional map. He also compares his method to cube and dual-paraboloid shadow mapping and concludes that it is faster than cube shadow maps and more accurate compared to dual-paraboloid shadow maps.

In “Screen Space Soft Shadows,” Jesus Gumbau, Miguel Chover and Mateu Sbert describe a soft shadow map technique that is built on Randima Fernando’s “Percentage-Closer Soft Shadows” and improves on the original idea in speed and flexibility. They use a screen-aligned texture that contains the distance between the shadow and potential occluders and then use this to run an adjustable anisotropic Gauss filter kernel over the original shadow data. This method is quite efficient and has a robustness that makes it suitable for game usage.

“Variance Shadow Maps Light-...

Table of contents

• Cover
• Halftitle
• Title Page
• Copyright Page
• Table of Contents