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FreeTrack Forum > FreeTrack : English Forum > Support : Tracking System > Axis representation correction and some questions

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Gian92 #1 08/04/2012 - 20h28

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Hello folks, I've just registered to this marvellous forum and I'd like to express my gratitude.
Besides this, since I've found some major flaws in an illustration while reading the FreeTrack handbook I wanted to fix them.

So here is a brand new 4 LED axis representation:

Posted Image

You can freely use this pic as long as you give some credit  ^^


I'd like also to ask you some questions:

Is there a specific reason why LED 2 has this position (was it upturned to follow the shape of the hat)?
Do I worsen the accuracy if I change the Y axis value of LED 2?
Does a 3-LED clip behave as good as a 4-LED system? If so, could you please recommend me a good and up-to-date 3-LED clip guide? Thanks
Ordem e progresso” - Brazilian flag
Steph #2 09/04/2012 - 16h50

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Very nice picture.
The thing is, that the handbook needs to be rewritten and updated to version 2.2.
The 4 LED Version is outdated and replaced by the 3-point cap version. ^^
So , no need to add the LED 2.

Does a 3-LED clip behave as good as a 4-LED system? If so, could you please recommend me a good and up-to-date 3-LED clip guide? Thanks



The 3-point clip works as well as the 3-point-cup if the dimensions-setup are well done.
See: Dimension setup 3-LED-cup
The model position corrections are very important for the 3-point-clip.

For 3-point-clip go here:http://forum.free-track.net/index.php?showtopic=1856&message=12649

...and these dimensions are not far away from default and works very well:
3-point-clip
Gian92 #3 09/04/2012 - 23h46

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Thanks for the reply  :)

In the handbook is written that you need to place the XYZ value of each LED in the [LEDs] section of the Freetrack.ini file, having as reference the centre (0,0,0).

In the current .ini document I don't see any [LEDs] section but instead:

[Threepoint_clip_dimensions]
[Threepoint_cap_dimensions]
[Fourpoint_dimensions]

As I can understand these sections replace the [LEDs] one, don't they?
Furthermore, in the current configuration I don't have to figure out the centre (0,0,0) to build the system, but just the relative distance between each LED, right?
Ordem e progresso” - Brazilian flag
Steph #4 10/04/2012 - 10h09

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You do not need to edit the Freetrack.ini. Just set up your model-dimensions in the model-panel in program.

Like this for example (3-point-clip):
Posted Image
Edited by Steph on 08/11/2012 at 10h28.
Gian92 #5 10/04/2012 - 14h02

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I see, thank you. Do I improve accuracy by spacing out more the two decentred LEDs vertically and laterally? Or is the achieved accuracy with the standard dimensions enough?
Another perhaps educated guess is that it is best to position the webcam right at the centre: centred vertically= (78+58)/2 and sideways, isn't it?

Please forgive my silly paranoia and punctiliousness but I always desire to clarify the smallest details to feel comfortable.
Edited by Gian92 on 10/04/2012 at 14h03.
Ordem e progresso” - Brazilian flag
Steph #6 11/04/2012 - 13h55

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The default dimensions works very well. You can scale up the clip, but the gain en precision isn't that great. Also it will be less handy, which is the first advantage of the clip version.

Another perhaps educated guess is that it is best to position the webcam right at the centre: centred vertically= (78+58)/2 and sideways, isn't it?



Yes. You can do this, (as far as I understand this options), also by given the angles to the webcam under "Cam"->"Orientation"
Posted Image

Please forgive my silly paranoia and punctiliousness but I always desire to clarify the smallest details to feel comfortable.



Np. Freetrack demands some own initiative to find a good setup due to use of individual hardware (webcam and tracking-model), but then it works as well as TrackIR. (I used both).
Use it for a while, to find out about all the settings and options is the best way to find a good configuration.
Gian92 #7 11/04/2012 - 14h12

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Well, many thanks for all the help, your wisdom is much appreciated  ^^
If you want we could write the handbook from scratch contacting an admin first.
The current manual is quite useless and its non up-to-dateness gives the site a "ghostly" feeling. What do you think about it?
Ordem e progresso” - Brazilian flag

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