Openvibe and a virtual keyboard

[fleur]

Hello,

I would like to connect my virtual keyboard on Windows with openvibe.
I don't clearly understand how I do the link.
I understand that I have to download a VR software like OpenMask or I have to download a 3D engine like Ogre3D, 3DVia Virtools Quest 3D.
I do the link with Openvibe- the VR Software or Engine- the virtual keyboard?
I should use the boxes:Button VRPN server and Analog VRPN Server and connect them with the VR Software ? Can I do the link with my virtual keyboard directly?
Thank you,

[yrenard]

Dear fleur,

I think that you have not understood how to connect OpenViBE with other applications. In order to perform such connection, we use the VRPN library. VRPN kindly abstracts any VR (as in Virtual Reality) device to a VR application. VR devices include motion trackers, data gloves, joysticks etc... VRPN being integrated in OpenViBE, you can make OpenViBE appear as a VR device to any VR application supporting VRPN devices. As stated in other topics, most VR application/engine support VRPN natively.

In your case, if you want to connect OpenViBE to your virtual keyboard, you won't need any thirdparty VR application. Better you should include some VRPN code in your virtual keyboard so it can natively receive messages from OpenViBE. See this sample code for an idea of how to put VRPN into your virtual keyboard application.

Keep us informed,
Yann

[lbonnet]

Hi fleur,

Just to complete what Yann said :
We have 2 VRPN Servers : the Analog VRPN Server box (for values) and the Button VRPN Server (for ON/OFF switches).

Once you run a scenario using these boxes, Analog and/or Button information are available for further use by an external application. Such application must implement a VRPN client and connect to the openvibe VRPN server(s).

If you can modify the code of your virtual keyboard, just add a VRPN client and connect it to the openvibe vrpn server(s).

Regards,

Laurent-

[fleur]

If I understand, I should put the code (you give me the link) into my main? How I install the VRPN client?

Best Regards,

[yrenard]

Dear fleur,

we don't know how your code is organized so I can't tell if main is the right place to put this code or not (it's probably not the right place however). Additionally, the code I pointed out was an example of how it works. You will have to integrate that in your own code !

Yann

[fleur]

Hello,

Thank you for your help.
I have this error on the console : "no response from the server"
I think that the error is in: ana = new vrpn_Analog_Remote("openvibe-vrpn@localhost");
I don't think that I should put: ("openvibe-vrpn@localhost"), do I ?

Best Regards,

[fleur]

Hello,

I have found my mistake.

Best Regards,

[yrenard]

Dear fleur,

congratulations for integrating VRPN in your virtual keyboard application. Keep us posted about the use of OpenViBE to control your application !

Yann

[fleur]

Hi,

I have not completely succeed to integrate the VRPN program. I have read the developer documentation on internet and I don't really understand how to use the VRPN button. Indeed, if I would like to simulate button press and release. In my application, the user can press the buttons 1 , 2 or 3 . I don't understand how to integrate that.
In my case, do I need the VRPN server? How do I parameter the VRPN button?
Thank you.

Sharmini KAMALAKUMAR

[yrenard]

Dear fleur,

the VRPN server is on the openvibe side. Your objective is to have a working VRPN client on the virtual keyboard side. If you want to have similar behavior as what you had with your real keyboard in the past, you should mix the Keyboard Stimulator box and the VRPN Button Server box. The first one will catch the real keyboard keys and transform them in to OpenViBE stimulations. The second one will expose these stimulations as VRPN buttons. Finally, your virtual keyboard will get those VRPN button states from the VRPN client object you have integrated.

You don't need to compile / use the vrpn_server application that comes with the official VRPN package.

Hope this helps,
Yann

[fleur]

Hello,

We're using an EEG build with OpenEEG and we are having trouble to extract command from the signal.
How can we use the classifier trainer and the classifier processor in order to simultate one command?
I have used the generic oscillator to test the classifier trainer but it doesn't generate the configuration file.

We are thinking to look at the level or the power of the signal while we are doing mental calculation.
Do you know other cerebral thought easier to use to get one command?

Thank you.

[yrenard]

Dear fleur,

attach a scenario of what you are doing please.

training a classifier on a sinus generated signal is probably not a good idea as you can imagine.

Yann

[fleur]

Hi,

I resolved my problem, I used the stimulation train trigger OVTK_GDF_end_of_file in the classifier trainer and I used the box Acquistion to get the signal. So the trigger was never activated.
I used a gdf reader file and it worked.

Can you please give us examples of simple cerebral commands in order to generate one command. For instance, can we think about movement of hand, mental calculation?

[yrenard]

Dear fleur,

you already have such sample files for motor imagery in the latest release. Have you checked those files ?

Yann