There are differences between the angles shown in my video compared to the angles copied from the data in the angular kinematics graph anywhere from 0.01 to 1.9 degrees for any time. I'm wondering why this is happening? Is it normal to have the two slightly differ? Is there a way to have the video and the data show the same angles? At first I went through and annotated the videos with the angle tool without calibrating, before going back and calibrating with the line tool, but nothing seemed to change. Any help?
- joan
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Regarding the first point it's not normal, the values should be the same, could you share the kva file with me please?
What do you have as options in Preferences > Drawings > General > "Enable coordinates filtering", and "Enable smoothing of derivatives for high speed footage"?
Do you have other calibrations in place like lens distortion calibration or camera motion estimation?
Assuming it's a tracked angle, are you using version 2024.1 or earlier or are you using version 2025.1? Tracking of objects changed completely.
For the second aspect, I think it's normal that when calibrating with the line tool it doesn't change the angle. It rotates, translates or scale the coordinate system but it's still on a parallel plane as the uncalibrated one so the angle shouldn't change. If you use the grid calibration to calibrate a plane that is not parallel it will change the measure.
It seems to be working now that I've turned off "Enable coordinates filtering". Thank you very much.
- joan
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You can read a bit more about the coordinates filtering in the about page of the Linear kinematics dialog. Usually you want to keep it on because it removes the high frequency noise that is artificially introduced by the digitization process, especially if the points are placed manually.
So it looks like the issue is that the angle value displayed in the viewport is not taking coordinates filtering into account, I will note it down somewhere, thanks.