Book Image

OpenGL Development Cookbook

By : Muhammad Mobeen Movania
Book Image

OpenGL Development Cookbook

By: Muhammad Mobeen Movania

Overview of this book

OpenGL is the leading cross-language, multi-platform API used by masses of modern games and applications in a vast array of different sectors. Developing graphics with OpenGL lets you harness the increasing power of GPUs and really take your visuals to the next level. OpenGL Development Cookbook is your guide to graphical programming techniques to implement 3D mesh formats and skeletal animation to learn and understand OpenGL. OpenGL Development Cookbook introduces you to the modern OpenGL. Beginning with vertex-based deformations, common mesh formats, and skeletal animation with GPU skinning, and going on to demonstrate different shader stages in the graphics pipeline. OpenGL Development Cookbook focuses on providing you with practical examples on complex topics, such as variance shadow mapping, GPU-based paths, and ray tracing. By the end you will be familiar with the latest advanced GPU-based volume rendering techniques.
Table of Contents (15 chapters)
OpenGL Development Cookbook
About the Author
About the Reviewers

Implemeting shadow mapping with percentage closer filtering (PCF)

The shadow mapping algorithm, though simple to implement, suffers from aliasing artefacts, which are due to the shadowmap resolution. In addition, the shadows produced using this approach are hard. These can be minimized either by increasing the shadowmap resolution or taking more samples. The latter approach is called percentage closer filtering (PCF), where more samples are taken for the shadowmap lookup and the percentage of the samples is used to estimate if a fragment is in shadow. Thus, in PCF, instead of a single lookup, we sample an n×n neighborhood of shadowmap and then average the values.

Getting started

The code for this recipe is contained in the Chapter4/ShadowMappingPCF directory. It builds on top of the previous recipe, Implementing shadow mapping with FBO. We use the same scene but augment it with PCF.

How to do it…

Let us see how to extend the basic shadow mapping with PCF.

  1. Change the shadowmap texture minification...