TrackIR 3 with Projector

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magma
Posts: 9
Joined: Sun Dec 14, 2003 5:00 am

TrackIR 3 with Projector

Post by magma »

I have a projector that I use with my flight sims. I've used TrackIR 3 Pro in the past with a monitor just fine, but this is a new challenge to get it to work.

If I place it on my desk in front of me, it is too low to get a decent relative "up/down" movement. I can get side/side and down because it can see a change in distance. But going up there is virtually no relative movement upwards, the dot just disappears.

I'd prefer to use the vector (3 dot) option, but so far that is out of the question.

My desk and chair are very close to the wall so it is difficult to mount it behind me too, because the vector takes up most of the window. and turning my head, it leaves the window. I could probably do ok with the dot, but then I have to sit in the same damn spot every time.

My headphones don't have a microphone boom, but I even tried a set with that, and it still didn't seem to track to well.

I'm at a loss for what to do. Any additional suggestions would be greatly appreciated.

I have considered mounting it on the wall right next to my projector screen, but then it would be a good 7 feet or so from my head, and at an angle. Not only that, I would need to run a fairly long extension and have it run along the floor which isn't really an option because it is a walking area and would probably trip on it (unless I tape it, but then my wife would object).

It would be nice if Natural Point could come up with a slick solution for us projector owners, since this is used for simulations mainly, which are great fun with projectors.

[ January 26, 2006, 05:11 AM: Message edited by: magma ]
Birch
Posts: 1139
Joined: Thu Jan 30, 2003 5:00 am
Location: Corvallis, Oregon

Re: TrackIR 3 with Projector

Post by Birch »

Is there a possibility of locating the TrackIR behind you so that it is facing toward the back of your head? I believe that scenario works when the "invert" checkbox is used for most of the axes.
ajay501
Posts: 5
Joined: Tue Mar 14, 2006 5:00 am
Location: Tinley Park, Illinois, USA

Re: TrackIR 3 with Projector

Post by ajay501 »

UPDATED 5/26/06
The method I described earlier (below) turns out to be a bad idea. Having the TrackIR camera below eye-level may produce erratic tracking. If you have this setup and are having problems try placing the camera above eye-level.

************ earlier post **********
I taped the camera to the top of a flashlight which is set on a desktop in front of the projector screen. It gives the camera just enough hieght if the middle reflector bar is bent forward. Works fairly well for a projector setup.

[ May 26, 2006, 08:12 AM: Message edited by: ajay ]
refields
Posts: 13
Joined: Wed Sep 07, 2005 5:00 am

Re: TrackIR 3 with Projector

Post by refields »

TrackIR images in the near infrared. That's why you can just see the glow of the illumination LEDs. They don't look bright to us because we don't see well in the near IR and what they emit and what we see just barely overlap.

All that said, a mirror should still work well enough at the TrackIR wavelength. Any way you can bounce the image with a mirror?

Not knowing how much trouble you want to go through, you might even be able to bouce the image with a sheet of glass. You look through it to see your projector image and the TrackIR sees your reflection bounced off the glass. See my post over in the Vector Expansion thread about how reflector gunsights work. The TrackIR would go at the bottom and look up. That's what I'm getting at but you would obviously need a bigger piece of glass so you could always see your projected display as you move through your range of motion.

Does any of that make sense?
rodom
Posts: 581
Joined: Thu Jul 07, 2005 5:00 am
Location: Philomath, OR

Re: TrackIR 3 with Projector

Post by rodom »

quote:Originally posted by 475th_Grumps:
TrackIR images in the near infrared. That's why you can just see the glow of the illumination LEDs. They don't look bright to us because we don't see well in the near IR and what they emit and what we see just barely overlap.

All that said, a mirror should still work well enough at the TrackIR wavelength. Any way you can bounce the image with a mirror?

Not knowing how much trouble you want to go through, you might even be able to bouce the image with a sheet of glass. You look through it to see your projector image and the TrackIR sees your reflection bounced off the glass. See my post over in the Vector Expansion thread about how reflector gunsights work. The TrackIR would go at the bottom and look up. That's what I'm getting at but you would obviously need a bigger piece of glass so you could always see your projected display as you move through your range of motion.

Does any of that make sense?Now thats one way I have not heard of yet. Not sure if it would work... interesting!
refields
Posts: 13
Joined: Wed Sep 07, 2005 5:00 am

Re: TrackIR 3 with Projector

Post by refields »

Hi Rick,

I just tried it - both with a mirror and with a piece of plate glass using the View/Tracking option in the software.

The mirror method works great. The plate glass idea doesn't - at least not the way I was doing it. The TrackIR could see the reflectors through the glass but not their reflection. (edit - But see updates below - it does work)

I think the LEDs are too close to the visible. Maybe there was something with the way I was doing it but since the image was so clear through the glass, you would lose a lot of the image at each bounce (bounce the illumination then bounce the image of the hat reflectors). Maybe it's just too faint for the TrackIR to lock onto it.

At any rate, it looks like it's pretty trivial to bounce the image with mirrors but with the unit itself being so small, the only reason you would need to do that would be to get it far enough away from the reflectors to allow more freedom of movement without going outside the TrackIR field of view.

I know this is a reach, but if a person wanted to add their own illumination, they could hit the relectors pretty hard and I'll bet enough of the image would make the bounce back to the track IR unit. This only works if the LEDs aren't modulated in some synchronous way with image readout. My bet is they are just on in which case the extra light would probably let the reflector image make the bounce to the TrackIR with enough brightness to allow tracking.

[ March 18, 2006, 11:22 AM: Message edited by: 475th_Grumps ]
refields
Posts: 13
Joined: Wed Sep 07, 2005 5:00 am

Re: TrackIR 3 with Projector

Post by refields »

Update - I just remembered the "Light Filtering" option under "Settings". If you turn that down to minimum, it will work with a piece of plate glass.

The image was fairly faint but it was there and it tracked.

If the illumination LEDs are not modulated, then a person could add their own non-bounced illumination and get enough of a reflected image to make for great tracking.

A head-tracking heads-up display of sorts.

Can you tell us the wavelength of the LEDs? Should be pretty easy to guess though if you can't. Human vision goes out to about 700 nm and Fairchild makes LEDs at 697 nm. That should be visible but dim.

Maybe if you guys made an auxiliary illuminator or sold LED packs for experimentors?
refields
Posts: 13
Joined: Wed Sep 07, 2005 5:00 am

Re: TrackIR 3 with Projector

Post by refields »

One more update

I don't believe there is any modulation or if there is, it doesn't matter. The TrackIR will track a flashlight bulb just fine.

I also tried to see how well it would see conventional red LEDs - not very well. But it did see them.

That said, I think if someone wanted to do the bounce through glass idea, all they would need would be an auxiliary IR light source and those are readily available already built for night vision CCTV applications. All the TrackIR is is a solid-state camera. So illumination for night-vision cameras should work great.

So, view the projecter image through a plate of glass positioned at about 45 degrees to the line of sight between pilot and screen. Have the TrackIR look up at the plate glass where it would see the track hat (imagine the plate glass as a mirror for this), throw a little more illumination at the track hat to get enough of a reflected image back to the TrackIR, and adjust the Light Filtering setting as needed to get good tracking of the reflectors but rejection of everything else.

The only other thing they might want to do is disable the LEDs on the TrackIR itself so that they didn't appear to float in the view of the projector screen (since this is basically a heads-up display - just twisted a little for the TrackIR - we don't really want anything to display). NaturalPoint conveniently provides a checkbox on the Settings page to do just that.

It should work great.
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