Head turning sensing

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cuvy
Posts: 2
Joined: Sun May 29, 2005 5:00 am
Location: Brisbane, Australia

Head turning sensing

Post by cuvy »

Hi,

I'm looking to develop a system for detecting head turns by participants as part of a research project i'm working on. I've had a look at the OptiTrack system, and it looks like it would be more than able to meet my needs.

I am, however, wondering whether I'd be able to use a trackIR unit instead, as basically all i'd be doing is positioning the unit behind the person, and logging when a reflective dot came into view (and potentially a bit more info about fixation and duration).

Two reasons why the TrackIR unit interests me are a) the lower cost, and b) the neater packaging, as we'd potentially be using these in environments like operating theaters.

So basically, my questions are, will the TrackIR meet these needs? Would implementing this sort of functionality in the TrackIR SDK be any different from the OptiTrack SDK, and does a usage like this go against any of the licensing requirements of the TrackIR SDK?

Thanks,
Phil
Jim
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Location: Corvallis, Oregon
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Re: Head turning sensing

Post by Jim »

Hello:

Thanks for your interest in our products!

Think of the TrackIR SDK as more of a plug-in for game developers that just gives them the values associated with the 6DOF Vector output. The OptiTrack SDK actually allows you to integrate all the functionality directly into your application, without running the TrackIR software in the background. It also gives you a license to distribute your software with our embeded code. Finally, Vector is included with the OptiTrack, so that makes the prices closer, you do have to buy a clip though.

We can deliver OptiTrack units in the TrackIR case if you want. This is a common request, but we don't put the option on the web site because it would make things even more confusing! You must order over the phone or email in for this option.

Let me know how we can help further.
cuvy
Posts: 2
Joined: Sun May 29, 2005 5:00 am
Location: Brisbane, Australia

Re: Head turning sensing

Post by cuvy »

Hi,

One quick question - does the TrackIR casing have a threaded tripod mount?

Thanks,
Phil
Jim
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Location: Corvallis, Oregon
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Re: Head turning sensing

Post by Jim »

No, but you could remove the bottom stand mount and drill out a hole for a mount, that would work. OptiTrack does have a standard 1/4-20 "tripod" thread mount.
orbtechsims
Posts: 12
Joined: Thu Dec 09, 2004 5:00 am

Re: Head turning sensing

Post by orbtechsims »

Hello, I am looking at the OptiTrack SDK for a very similar need- actually what I need is to in a sense recreate TrackIR but with different specifications to meet my requirements. Could you tell me if the Optitrack + SDK are capable of meeting my needs, which are:

- 180 degree yaw head tracking from behind head, i.e. 90 degrees +/- (possibly using IRLEDs instead of reflective dot)

- Ability to output current "head yaw reading" for use in other software running simultaneously

- Emulate mouse so no game modification is needed

I am very interested to hear about the functionality or the SDK and OptiTrack. It may be one of the only solutions on the market today for my needs. Thank you for your help.

[ June 14, 2005, 01:14 PM: Message edited by: orbtechsims ]
Birch
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Joined: Thu Jan 30, 2003 5:00 am
Location: Corvallis, Oregon

Re: Head turning sensing

Post by Birch »

- The Vector tracking component of the OptiTrack API provides the ability to track 100 degrees of yaw (+/- 50 degrees) when using the Vector Clip in the standard configuration of the imager looking forwards at the clip.

If you wish to implement your own 6DOF tracking calculation, it is possible to achieve a higher range of yaw tracking.

- All of the Vector tracking data is available in real time via the API, including the Yaw value. You can read this data from the API and write code to send it to other applications.

- Support for mouse emulation is not provided with the OptiTrack SDK.

If you can more precisely describe your target application, we may be able to provide you with more information to assist you in determining whether OptiTrack is the right solution for you.

If you wish, you can also contact us at sales@naturalpoint.com

[ June 16, 2005, 05:58 PM: Message edited by: NaturalPoint - Birch Zimmer ]
orbtechsims
Posts: 12
Joined: Thu Dec 09, 2004 5:00 am

Re: Head turning sensing

Post by orbtechsims »

Hello, thank you for your reply.

- Our application only requires 2 degrees of tracking; Yaw and Pitch. Being so I would not need Vector. Could and active IR LED emitter be used to achieve 180 degree tracking (90 +/-)? How complex is it to write custom tracking calculations to achieve this?

- What is the resolution/precision in degrees of OptiTrack? I would be hoping for around 1 degree of precision.
Birch
Posts: 1139
Joined: Thu Jan 30, 2003 5:00 am
Location: Corvallis, Oregon

Re: Head turning sensing

Post by Birch »

In order to derive rotational movement along an axis without interference from movement along other axes, it is usually best to derive all 6DOF (depending upon your particular implementation).

If you plan to track a single LED source, it may be difficult to distinguish the difference between translation and rotation movements unless your application will not be subject to any translation.

The effort required to develop a custom solution to meet your tracking needs will depend upon your familiarity with optical tracking applications and math.

The Vector tracking in OptiTrack has a resolution of better than 1/2 a degree in the Yaw axis at 100cm without smoothing applied.

If you would like assistance in developing a custom solution for your application, you can send project details to sales@naturalpoint.com.

[ June 18, 2005, 01:31 AM: Message edited by: NaturalPoint - Birch Zimmer ]
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