VRPN Client Plugin
Virtual Reality Peripheral Network (VRPN) is a device-independent system for accessing virtual reality peripherals in VR applications. The VRPN system consists of programming interfaces for both the client application and the hardware drivers and a server application that communicates with the hardware devices. The DTrack application often goes as a server application.
The Virtual Reality Peripheral Network (VRPN) plugin represents the client application which is connected to the server and used for receiving input data from different input devices (joysticks, 3D motion and orientation tracking sensors and so on) via the Network.
For example, by using the VRPN Client plugin, you can implement an application that processes input data from ART controls.
See Also#
- VrpnAnalogDevice class
- VrpnButtonDevice class
- VrpnTackerDevice class
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Samples on the plugin usage:
- <UnigineSDK>/data/samples/plugins/vrpn_client_00 that demonstrates receiving data from the FlyStick device and two sensors, tracking this device and a head. The data is presented as a text.
- <UnigineSDK>/data/samples/plugins/vrpn_client_01 that demonstrates receiving data from the virtual FlyStick device and two sensors, tracking this device and a head, inside the UNIGINE scene.
The samples are available if you add the VRPN Client plugin to your project via UNIGINE SDK Browser.
Launching VRPN Client Plugin#
To use the VRPN Client plugin, you should specify the extern_plugin command line option on the application start-up:
main_x64 -extern_plugin "UnigineVrpnClient"
Implementing Application Using VRPN Client Plugin#
When the VRPN Client plugin is loaded, the following classes are added to UnigineScript:
- VrpnAnalogDevice that receives data about input devices sticks.
- VrpnButtonDevice that receives data about input devices buttons states.
- VrpnTrackerDevice that receives about position, orientation, velocity and acceleration of tracked objects from 3D tracking sensors.
When implementing an application using the plugin, instances of the classes listed above should be created on engine initialization.
For example, if the VRPN server is set on the PC via the DTrack application, the following should be passed: DTrack@localhost. If the server is set on another PC, instead of the localhost, you should specify the PC's IP address. You should also call the update() method for each initialized device on engine update.
#ifdef HAS_VRPN_CLIENT
VrpnTrackerDevice tracker;
VrpnButtonDevice button;
VrpnAnalogDevice analog;
int init() {
tracker = new VrpnTrackerDevice("DTrack@localhost");
button = new VrpnButtonDevice("DTrack@localhost");
analog = new VrpnAnalogDevice("DTrack@localhost");
return 1;
}
int shutdown() {
delete tracker;
delete button;
delete analog;
return 1;
}
int update() {
tracker->update();
button->update();
analog->update();
return 1;
}
#else
int init() {
Log::warning("No VRPN Client plugin detected\n");
return 1;
}
int shutdown() {
return 1;
}
#endif