1 Topic by pmtanx

  • pmtanx
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Hello,

I believe I have found a bug in the goniometer tool. I have been able to replicate it in multiple videos with the following steps:

1. Open a video.
2. Select the goniometer tool and place a goniometer in a frame. By default, the stationary arm points to 9 o'clock, the moveable arm to 1:30, and the reference axis to 3 o'clock, so that the angle measures 45°.
3. Move the reference axis down to 6 o'clock, so that the angle measures 135°.
4. Right click the object and select Start Tracking. At this point, the reference axis jumps over to 7:30 such that the angle now measures 180°.

Oddly, this problem only seems to occur when the reference axis is 90° counterclockwise of the stationary arm. It doesn't occur when the reference axis is anywhere else with respect to the stationary arm, but it does occur even if I adjust all of the arms before beginning tracking.

Thanks,
Philip

Philip Tan
Assistant Professor of Engineering
Messiah University
Grantham, PA

2 Reply by joan

  • joan
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Interesting! thanks, I can reproduce the problem.

3 Reply by joan

  • joan
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The problem was that the endpoint of the reference axis was set to be trackable, but since this is an abstract axis that is always defined in relation to the stationary arm it shouldn't be tracked. The inconsistent behavior comes from a conflict between the manipulation constraints system and the tracking.

I fixed it in the development version. It's also possible to fix it on your end by modifying the goniometer tool file manually:

<Kinovea program files>\DrawingTools\Custom\1 - Goniometer.xml

At line 45, remove trackable="true" (or replace it with trackable="false").

4 Reply by pmtanx

  • pmtanx
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Thank you! I am very grateful for Kinovea and for your continued improvement of it!

Philip