In this chapter, we will introduce primary datatypes of the OpenNI and the NiTE along with some basic information about how to access and select a data stream. Then we will try to show you some examples of events triggered by devices such as connecting or disconnecting an OpenNI supported device from computer.
But first, let's get some background about the whole OpenNI's principle first.
OpenNI object is the starting point of everything in the framework. Using the OpenNI class we can access a list of connected devices as well as the version of OpenNI itself. Then using this information we can access a device object and read data.
This class uses the singleton pattern, which means there is only one instance of this class and all of its methods are static.
Also in OpenNI 2 we have the ability to register two callback functions by OpenNI object for capturing device connected and device disconnected events.