Book Image

OpenNI Cookbook

By : Soroush Falahati
Book Image

OpenNI Cookbook

By: Soroush Falahati

Overview of this book

The release of Microsoft Kinect, then PrimeSense Sensor, and Asus Xtion opened new doors for developers to interact with users, re-design their application’s UI, and make them environment (context) aware. For this purpose, developers need a good framework which provides a complete application programming interface (API), and OpenNI is the first choice in this field. This book introduces the new version of OpenNI. "OpenNI Cookbook" will show you how to start developing a Natural Interaction UI for your applications or games with high level APIs and at the same time access RAW data from different sensors of different hardware supported by OpenNI using low level APIs. It also deals with expanding OpenNI by writing new modules and expanding applications using different OpenNI compatible middleware, including NITE. "OpenNI Cookbook" favors practical examples over plain theory, giving you a more hands-on experience to help you learn. OpenNI Cookbook starts with information about installing devices and retrieving RAW data from them, and then shows how to use this data in applications. You will learn how to access a device or how to read data from it and show them using OpenGL, or use middleware (especially NITE) to track and recognize users, hands, and guess the skeleton of a person in front of a device, all through examples.You also learn about more advanced aspects such as how to write a simple module or middleware for OpenNI itself. "OpenNI Cookbook" shows you how to start and experiment with both NIUI designs and OpenNI itself using examples.
Table of Contents (14 chapters)
OpenNI Cookbook
About the Author
About the Reviewers


In this chapter, we are going to cover every topic related to hand tracking in NiTE, from finding hand gestures to tracking hand movements and finding which hand belongs to which user.

Unfortunately, the new version of NITE does not have some commands, such as the hand swipe, from the old API.

The nite::HandTracker object

Just as with nite::UserTracker, which is responsible for giving us information about users, nite::HandTracker is responsible for giving us information about hand tracking and hand's gestures on the scene. The two main functionalities of nite::HandTracker are recognizing hand gestures and tracking hands. Let's take a look at the important methods of this class:

  • nite:HandTracker::startGestureDetection(): This method starts the process of searching for a specific hand gesture in the scene. It accepts only a single argument from the nite::GestureType enum type. This enum type has three predefined members that are the only supported gestures by nite::HandTracker. It...