VRPN mouse allows you to use any VRPN input device to emulate a standard desktop mouse. In other words, it is a mouse emulation for X11 that maps a 3D, 6-degrees-of-freedom (6DOF) tracking device onto the 2D screen.
The motivation behind VRPN mouse is that people sometimes want to use a desktop program on a powerwall display. While it is possible to just connect a desktop mouse to the display directly, often this is impracticable (e.g. no suitable surface for using the mouse) and a 6DOF tracking device is already available without additional setup.
- X11 server with XTest extension enabled
- VRPN
VRPN mouse needs one input tracking device, plus one button device (both can be the same). A typical setup might look like this:
vrpnmouse --movebutton 4 --lmb 1 --mmb 2 --rmb 3 powerwalltracker@mytrackinghost 4 wiimote@mytrackinghost
This means that the tracker with index 4 on the VRPN device
powerwalltracker@mytrackinghost is used, together with the button input
from wiimote@mytrackinghost.
In the example shown, mouse movement is only enabled when button 4 is pressed
(--movebutton 4). If you want the movement to be always enabled, omit the
--movebutton argument.
In case your tracker device is not perfectly aligned with the "perceived
orientation" of the device, you can calibrate the orientation by adding the
--calibrate argument. At startup, the program will then prompt you to
point the device towards the screen and press any button.
As part of the calibration step, the calibration data is displayed as follows: Calibration data: [0.585161,0.355244,0.359502,0.634164]
To avoid the manual prompt in the future, you can directly set the calibration data on startup:
vrpnmouse --movebutton 4 --lmb 1 --mmb 2 --rmb 3 powerwalltracker@mytrackinghost 4 wiimote@mytrackinghost -c [0.585161,0.355244,0.359502,0.634164]
Please note that no whitespace is allowed within the calibration data.
While the program comes with a default setting for the physical screen setup, you will most certainly want to adopt this to your needs.
Assuming that you use a powerwall setup which is 5 meters wide, and 2 meters high from the floor. If the coordinate-system origin is situated 1.5 meters in front of the screen-middle on the floor, the following screen definition would suit your needs:
vrpnmouse --movebutton 4 --lmb 1 --mmb 2 --rmb 3 powerwalltracker@mytrackinghost 4 wiimote@mytrackinghost --screen [-1.5,-2.5,2.5,0.0,2.0]
Please note that no whitespace is allowed within the screen definition.
- vrpnmouse uses sscanf for parsing of the --calibration-data and --screen arguments
- jitter in the tracking data is not smoothed out