FreeTrack Forum

Hi there. I just wanted to say that as a first-time user, I am very impressed by Free-Track and how well it works.

In fact, it is so efficient in 2DOF mode that I'm even using this system to design the world's first optically-tracked motion platform! The project is going very smoothly, but I have encountered a small problem.

Free-Track will only run in one instance. If I am using it for my platform's tracking system (through PP2Joy), this will leave me without head tracking. The only workaround I can foresee for this is purchasing a TrackIR for separate use - which is the situation I was trying to avoid in getting Free-Track in the first place!

The ability to select your webcam device from a list seems to be in place already, so this problem could be worked around by removing the restriction of having only one Free-Track instance running at a time.

Please let me know if there are any other limitations that may prevent the implementation of this solution.

With First release of freetrack there was no instance limitation (FreeTrack 1.1) !

But FPS was very very slow, if many instance was launch ... So to prevent this kind of problem we have had a sofware instance limitation ...

I think the Wiimote is a better solution for multiple instances because it won't burdon the processor.  Time  Lag can be a killer for many types of motion sensing.

At $40 each, it is also a fairly cheap solution.  The integration of the Wiimote will be a great asset in the next version.

I imagine there are other hardware solutions.  The CMU Cam is another one, but is more expensive.  However, it might be an advantage that it can track colors. I have no idea if this unit has ever been used for VR tracking.  http://www.cmucam.org/

Joe Dunfee

I would expect that multiple instances would probably cause some memory issues. However, I think it would be beneficial to allow under some unique circumstances, as a lot of Free-Track's users are flight sim nuts who may need to experiment with odd concepts like this.

May I suggest replacing the termination script with a dialog that provides the user with a warning that there's already an instance running? This would let the user decide whether to continue. This dialog would also alert the careless user that they may be about to make a mistake.

Such a dialog could go something like this;

Warning: An instance of Free-Track is already running on this system. Opening another instance may use up more system resources and affect performance. Would you like to continue?

[OK][Cancel]

cadcoke4: Using a Wiimote, unfortunately, is not possible with this project because of some unusual design limitations. The project calls for either vanilla Free-Track (that is, with a webcam and LED's). These same design limitations are also what prevent me from using TrackIR.

I appreciate your feedback, and believe me, I'd much rather use a Wiimote than IR LED's if I could. However, the option is not available to me at this time.

I am curious about the limitations you are talking about.

The WiiMote gives you up to 4 points of tracking and gives you the locations of those dots in the image.  This is obviously the first processing effort the FreeTrack program must do.  So, I would imagine this data just needs to get inserted at this point in the software. But, I do acknowledge my ignorance about the details of the FreeTrack software.

Joe Dunfee

Joe~

Thanks for writing back - I'll be more than happy to go into further details, if you feel it would help.

The most important limitation of my design is that FreeTrack is driving ROCKEYE II. This is essentially an infrared "antenna" of my own design mounted onto the underside of the motion platform.

This antenna utilizes a single infrared LED, which is tracked in 2DOF by Free-Track's joystrick emulation, PP2Joy. The webcam is below the seat, looking straight up at the underside, and sees the tip of the antenna move as the platform pitches and rolls.

This translates into X and Y coordinates that are registered by the simulator as joystick input. The ROCKEYE system doesn't need 6DOF tracking for this purpose, as the motion platform only pitches and rolls.

The platform needs to be built in this fashion to eliminate several mechanical problems inherent in its original design that I cannot correct otherwise.

Respectfully, if I have to explain the limitations of the project further than this, it becomes neccessary for me to type up a complete, seven-page essay on how the motion platform works. I'd rather avoid that, as I'm at work and cannot risk having my supervisor see me doing that on their dime.

I would also like to point out that no matter how useful it would be otherwise, however little system resourses it requires, etc, etc, even a Wiimote is completely worthless to me if Free-Track is already busy watching my motion platform's underside.

Please don't misunderstand my tone in my writing today - I do not expect to ask the good folks behind this brilliant piece of software to make a drastic, last-minute change before rolling out v2.2, on my account alone.

However, I do feel that having the option in this case to run more than one instance would allow many sim enthusiasts to explore their options in building pits, and I appreciate having the opportunity to make the suggestion hopefully for v2.3 or later!

After a long weekend setting up and configuring both FSX and FS9, I’ve found that between the Saitek x52 Pro, my trackball, and a Gamer Command unit, I actually have TOO MANY controls to assign even without a head-tracking system. Throwing in the head tracking would give me a mini-mouse axis and a scroll button/wheel I’m just going to need to assign something else to.

Given that the “nipple” on the throttle assembly works just fine in ActiveCamera (FS9) and Mouse Look (FSX), I’m going to swallow the multiple-instance limitation of the software and use the Free-Track software for the ROCKEYE II and keep handling head control with the Saiteks.