Mastering openFrameworks: Creative Coding Demystified

Denis Perevalov

• Publisher: Packt Publishing
• Year: 2013
• eBook ISBN: 9781849518048
• Edition: 1
• Topic: Computer Science
• Subtopic: Computer Vision & Pattern Recognition
• Index: Computer Science

In Detail

openFrameworks is a powerful programming toolkit and library designed to assist the creative process through simplicity and intuitiveness. It's a very handy software library written in C++ to reduce the software development process, helping you to kick-start creative coding. With the help of C++ and shaders support, openFrameworks allows for the processing of all kinds of media information with your custom-developed algorithms at the lowest possible level, with the fastest speed.

"Mastering openFrameworks: Creative Coding Demystified" will introduce you to a world of creative coding projects, including interactive installations, audio-visual, and sound art projects. You will learn how to make your own projects using openFrameworks. This book focuses on low-level data processing, which allows you to create really unique and cutting-edge installations and projects.

"Mastering openFrameworks: Creative Coding Demystified" provides a complete introduction to openFrameworks, including installation, core capabilities, and addons. Advanced topics like shaders, computer vision, and depth cameras are also covered.

We start off by discussing the basic topics such as image and video loading, rendering and processing, playing sound samples, and synthesizing new sounds. We then move on to cover 3D graphics, computer vision, and depth cameras. You will also learn a number of advanced topics such as video mapping, interactive floors and walls, video morphing, networking, and using geometry shaders.

You will learn everything you need to know in order to create your own projects; create projects of all levels, ranging from simple creative-code experiments, to big interactive systems consisting of a number of computers, depth cameras, and projectors.

Approach

Stuffed with practical examples, this book gives clear and effective instructions to build your own fun, stunning, and highly-interactive openFrameworks applications. Each chapter is focused on one topic and has a new theme to it.

Who this book is for

If you are a visual artist, designer, or programmer interested in creative coding with openFrameworks then this book is for you. Basic knowledge of object-oriented programming, such as C++, Java, Python, and ActionScript 3, would be helpful.

Mastering openFrameworks: Creative Coding Demystified

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Table of Contents

Mastering openFrameworks: Creative Coding Demystified

Credits

Foreword

About the Author

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

Reader feedback

Customer support

Downloading the example code

Downloading the color graphics PDF

Errata

Piracy

Questions

1. openFrameworks Basics

About openFrameworks

Use cases

Installing openFrameworks and running your first example

Installing on Windows

Microsoft Visual Studio

Code::Blocks (Windows)

Installing on Mac OS with Xcode

Installing on Linux with Code::Blocks

openFrameworks' folders

The examples folder

The apps folder

The addons folder

File structure of a project

Code structure of a project

main.cpp

testApp.h

testApp.cpp

setup()

update()

draw()

Other functions

Creating a new project

Creating a project from an existing example

Creating a project using Project Generator

Creating your first project – the Pendulum example

Running the book's examples

Basic utility functions

Summary

2. Drawing in 2D

Drawing basics

The background color of the screen

Pulsating background example

Geometric primitives

The simplest example of a flower

Controlling the drawing of primitives

Using ofPoint

Operations with points

Using control points example

Coordinate system transformations

Flower with petals example

Colors

Operations with colors

Color modifications example

Drawing with an uncleared background

Using FBO for offscreen drawings

Spirals example

Playing with numerical instability

Screen grabbing

Additional topics

Summary

3. Building a Simple Particle System

The basics of particle systems

Interaction types

Computing particles' physics

Rendering particles

Creating a particle system – summary

A single particle

Control parameters

Defining the particle functions

Implementing a particle in the project

An emitter

The attraction, repulsion, and spinning forces

Graphical user interface

Additional topics

Summary

4. Images and Textures

Raster and vector images

Loading and drawing an image

Rotating images

Color modulation

Transparency

Creating and modifying images

Creating images

Modifying images

Working with the color of a single pixel

A simple geometrical distortion example

The functions for manipulating the image as a whole

Using ofTexture for memory optimization

Image warping and video mapping

Using images for internal calculations

An image as a mask

An image as a palette

Summary

5. Working with Videos

Video basics

Playing a video file

Controlling the video playback

Processing a single video frame

The vertical lines image example

The replacing colors example

Processing multiple frames

Radial slit-scan example

Horizontal slit-scan

Discussing color interpolation

Processing a live video from the camera

The video synthesizer example

Using image sequence

Using image sequence example

Summary

6. Working with Sounds

Sound basics

Playing sound samples

The bouncing ball example

The singing voices example

Generating sounds

The PWM synthesis example

Image-to-sound transcoder example

Using a microphone

The loop sampler example

Saving a recorded sample to the file

Getting spectral data from sound

Dancing cloud example

Summary

7. Drawing in 3D

3D basics

Representation of 3D objects

3D scene rendering

Simple 3D drawing

The triangles cloud example

Using ofMesh

Enabling lighting and setting normals

Computing normals using the setNormals() function

Drawing sharp edges

Drawing line segments and points

Drawing line segments

Drawing points

Coloring the vertices

Texturing

Working with vertices

The oscillating plane example

The twisting knot example

Additional topics

Summary

8. Using Shaders

Basics of shaders

Types of shaders

When to use shaders

Structure of a shader's code

A simple fragment shader example

Creating the fragment shader

The vertex shader

Embedding shaders in our project

Debugging shaders

Creating video effects with fragment shaders

Passing a float parameter to a shader

A simple geometrical distortion example

Passing the float array to the shader

Using Perlin noise in shaders

A liquify distortion example

Processing several images

A masking example

An audio-reactive project example

Deforming objects with a vertex shader

Vertex shader

Fragment shader

Using vertex shader in our project

Using a geometry shader

The furry carpet example

Additional topics

Summary

9. Computer Vision with OpenCV

Understanding computer vision and OpenCV

Using ofxOpenCv

Working with ofxCv images

Image initializing

Algebraic operations with images

Drawing functions

Access to pixels

Working with color planes and color spaces conversion

Motion detection from movies

Discussing the algorithm's parameters

Motion detection from live video

Image filtering

The image filtering example

Geometrical transformations of images

Perspective distortion removing example

Searching for objects in an image

Using the ofxCvContourFinder class for finding contours

An example for searching bright objects in video

Using OpenCV functions

Optical flow

Video morphing example

Using optical flow for morphing

Applying morphing to another image

Summary

10. Using Depth Cameras

Depth camera basics

Active infrared stereo cameras

Installing the ofxOpenNI addon

ofxOpenNI examples

Working with examples of depth images

Hand-tracking examples

User tracking examples

Creating in...

Table of contents

• Mastering openFrameworks: Creative Coding Demystified