FreeTrack Forum

Welcome, you're not connected. ( Log in - Register )

FreeTrack Forum > FreeTrack : English Forum > Support : Tracking System > 3 point clip calibration questions

RSS >  3 point clip calibration questions
Keiler #1 21/10/2007 - 13h36

Class : Apprenti
Posts : 5
Registered on : 21/10/2007

Off line

First off, a BIG thank you for taking the time of coding and developing such a wonderful tool!

I built a 3point clip which I mounted to the right side of my headset, and it works wonderfully with one exception. I dont seem to be able to adjust the calibration sliders in such a way, that Freetrack doesnt superimpose translation over rotations entirely. I can somehow minimize them, but I dont get rid of them fully.

Is there any tutorial or heads-up? I am a bit confused about the nomenclature of the sliders, the "Rolling x min/balance) is double, but seem to affect different axis.

Please help!

Best regards,
Matt

p.s.: Again, awesome job on developing Freetrack! Keep up the good work!
Keiler #2 23/10/2007 - 13h10

Class : Apprenti
Posts : 5
Registered on : 21/10/2007

Off line

No help? :(

I just would like to know how those 3point-clip calibration sliders exactly work, what they do in detail.

Kestrel? Anyone with a 3point clip? Can someone help me out?

Best regards,
Matt
Kestrel #3 23/10/2007 - 14h25

Webmaster (admin)
Class : Webmaster (admin)
Posts : 780
Registered on : 13/07/2007

Off line

Before calibrating, note the following:

Minimizing parasitic translation during rotation:

*Ensure the translation sensitivities aren't too high relative to the rotation sensitivities.
*Increase rotation sensitivity.
*Decrease translation sensitivity.
*Position webcam further away; allows the translation sensitivities to be reduced while still allowing for a large range of translation.
*Use a medium deadzone for the translation response curves  (right click -> deadzone -> medium deadzone).

Calibration involves telling FT where the clip is with respect to the neck pivot point. Not all parasitic translation can be eliminated.

To calibrate;

Position point model clip on headphones in the ideal, permanent position.

Use linear response curves for rotation and translation (right click -> linear).

For 'rolling (min/balance Y)':
1) Roll your head across the complete range
2) If the virtual head moves in the Y direction (up/down) adjust the 'rolling (min/balance Y)' parameter.
3) Move your head to center.
4) Press center.
5) Repeat 1-4 until virtual head Y motion is minimized and balanced while rolling.

Do a similar procedure for the other parameters.

Note there are two 'rolling (min/balance X)' parameters, requiring some extra fiddling.
Keiler #4 24/10/2007 - 07h14

Class : Apprenti
Posts : 5
Registered on : 21/10/2007

Off line

:)  Many thanks, Kestrel!! Will do that.

My best regards,
Matt
Bwaze #5 29/03/2008 - 18h36

Class : Apprenti
Posts : 4
Registered on : 02/02/2008

Off line

Hello.

I have been using FreeTrack for quite some time, it's working great, but I have several issues I can't seem to solve. One of them is unwanted translation when rotating head, seen in games that use 6DOF (FSX) and in games that use Z axis for zoom (Lock On 1.12). I use the 3-point clip.

Pitch rotation (up / down) is relatively stable, but yaw rotation (left / right) produces strong Z axis movement. This movement is almost as strong as when I move my head in Z axis for about 20 cm.

What am I doing wrong, and where can I fix this? In "Center of rotation calibration"?

It looks as if my clip is too far away from the centre of my head. Which setting would fix this?

My clip, stainless steel, default measurements (upper LED 60/60, lower LED 80/80 mm from center LED):

Posted Image

Posted Image

Right now rotation produces so much movement in Z axis it's almost unusable.
Pezzer Ritter wenne Chnecht!

 >  Fast reply

Message

FreeTrack Forum > FreeTrack : English Forum > Support : Tracking System > 3 point clip calibration questions

 >  Stats

1 user(s) connected during the last 10 minutes (0 member(s) and 1 guest(s)).