OpenSceneGraph 3.0: Beginner's Guide

Rui Wang, Xuelei Qian

• Verlag: Packt Publishing
• Jahr: 2010
• ISBN:
  9781849512831
• Auflage: 1
• Thema: Informatik
• Thema: Informationstechnologie

Written with a fast-paced but friendly and engaging approach, this Packt Beginner's Guide is designed to be placed alongside the computer as your guide and mentor. Step-by-step tutorials are bolstered by explanations of the reasoning behind what you are doing. You will quickly pick up the necessary skills, tips, and tricks for creating successful 3D graphics with practical examples that help you to learn by experiment and play. This book is intended for software developers who are new to OpenSceneGraph and considering using it in their applications. It is assumed that you have basic knowledge of C++ before using this book, especially the standard template library (STL) constructs, of which OSG makes extensive use. Some familiarity with design patterns as implemented in C++ is also useful, but is not required. You need to be familiar with OpenGL, the standard cross-platform low-level 3D graphics API. We'll meet some maths in the book—geometry and linear algebra—and familiarity with these topics will be great, but you don't need to be a maths whiz to use this book.

OpenSceneGraph 3.0

Beginner's Guide

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Table of Contents

OpenSceneGraph 3.0

Credits

Foreword

About the Authors

Acknowledgement

About the Reviewers

www.PacktPub.com

Support files, eBooks, discount offers and more

Why Subscribe?

Free Access for Packt account holders

Preface

What this book covers

What you need for this book

Who this book is for

Conventions

Time for action—heading

What just happened?

Pop quiz—heading

Have a go hero—heading

Reader feedback

Customer support

Errata

Piracy

Questions

1. The Journey into OpenSceneGraph

A quick overview of rendering middleware

Scene graphs

The Birth and development of OSG

Components

Why OSG?

Who uses OSG?

Have a quick taste

Time for action—say "Hello World" OSG style

What just happened?

Live in community

Summary

2. Compilation and Installation of OpenSceneGraph

System requirements

Using the installer

Time for action—installing OSG

What just happened?

Running utilities

Time for action—playing with osgviewer

What just happened?

Pop quiz—dependencies of osgviewer

Have a go hero—playing with osgconv

Using the project wizard

Time for action—creating your solution with one click

What just happened?

Have a go hero—constructing "Hello World" with the wizard

Prebuilts making trouble?

Cross-platform building

Starting CMake

Time for action—running CMake in GUI mode

What just happened?

Setting up options

Generating packages using Visual Studio

Time for action—building with a Visual Studio solution

What just happened?

Pop quiz—the difference between ALL_BUILD and 'build all'

Generating packages using gcc

Time for action—building with a UNIX makefile

What just happened?

Have a go hero—checking mis-compiled parts

Configuring environment variables

Summary

3. Creating Your First OSG Program

Constructing your own projects

Time for action—building applications with CMake

What just happened?

Pop quiz—configuring OSG path options yourselves

Have a go hero—testing with different generators

Using a root node

Time for action—improving the "Hello World" example

What just happened?

Understanding memory management

ref_ptr<> and Referenced classes

Collecting garbage: why and how

Tracing the managed entities

Time for action—monitoring counted objects

What just happened?

Have a go hero—returning from a function

Pop quiz—release a smart pointer

Parsing command-line arguments

Time for action—reading the model filename from the command line

What just happened?

Tracing with the notifier

Redirecting the notifier

Time for action—saving the log file

What just happened?

Summary

4. Building Geometry Models

How OpenGL draws objects

Geode and Drawable classes

Rendering basic shapes

Time for action—quickly creating simple objects

What just happened?

Storing array data

Vertices and vertex attributes

Specifying drawing types

Time for action—drawing a colored quad

What just happened?

Pop quiz—results of different primitive types

Indexing primitives

Time for action—drawing an octahedron

What just happened?

Pop quiz—optimizing indexed geometries

Have a go hero—challenges with cubes and pyramids

Using polygonal techniques

Time for action—tessellating a polygon

What just happened?

Rereading geometry attributes

Customizing a primitive functor

Time for action—collecting triangle faces

What just happened?

Have a go hero—analyzing topology of a geometry

Implementing your own drawables

Using OpenGL drawing calls

Time for action—creating the famous OpenGL teapot

What just happened?

Summary

5. Managing Scene Graph

The Group interface

Managing parent nodes

Time for action—adding models to the scene graph

What just happened?

Pop quiz—fast dynamic casting

Traversing the scene graph

Transformation nodes

Understanding the matrix

The MatrixTransform class

Time for action—performing translations of child nodes

What just happened?

Pop quiz—matrix multiplications

Have a go hero—making use of the PositionAttitudeTransform class

Switch nodes

Time for action—switching between the normal and damaged Cessna

What just happened?

Level-of-detail nodes

Time for action—constructing a LOD Cessna

What just happened?

Proxy and paging nodes

Time for action—loading a model at runtime

What just happened?

Have a go hero—working with the PagedLOD class

Customizing your own NodeKits

Time for action—animating the switch node

What just happened?

Have a go hero—creating a tracker node

The visitor design pattern

Visiting scene graph structures

Time for action—analyzing the Cessna structure

What just happened?

Summary

6. Creating Realistic Rendering Effects

Encapsulating the OpenGL state machine

Attributes and modes

Time for action—setting polygon modes of different nodes

What just happened?

Inheriting render states

Time for action—lighting the glider or not

What just happened?

Playing with fixed-function effects

Time for action—applying simple fog to models

What just happened?

Have a go hero—searching for more effects

Lights and light sources

Time for action—creating light sources in the scene

What just happened?

Pop quiz—lights without sources

The Image class

The basis of texture mapping

Time for action—loading and applying 2D textures

What just happened?

Have a go hero—making use of filters and wrapping modes

Handling rendering order

Time for action—achieving the translucent effect

What just happened?

Understanding graphics shaders

Using uniforms

Time for action—implementing a cartoon cow

What just happened?

Pop quiz—replacements of built-in uniforms

Have a go hero—setting vertex attributes to shaders

Working with the geometry shader

Time for action—generating a Bezier curve

What just happened?

Have a go hero—having fun with shaders

Summary

7. Viewing the World

From world to...