Left-handed coordinate system in Tracking Tools.

mores_p
Posts: 23
Joined: Sun Oct 28, 2007 11:23 pm
Location: Lafayette, LA, USA.

Left-handed coordinate system in Tracking Tools.

Post by mores_p »

Hello,

I am moving from the old point-cloud/rigid-body tools to the new tracking tools. I noticed a different in the default coordinate system.

In the old rigid body tool, the default is left-handed with an option to switch to right-handed. In the new tracking tools, the default is right-handed, and I see no option to switch the handedness. As my application assumes left-handed coordinate system, it would be convenient on my part if the tool allows me to revert back to the left-handed system. Do I miss something?

Also, the snap feature of a rigid body pivot point to one of the markers is still missing in the newest version. Is there any plan to incorporate this feature back real soon?

Thank you,
Mark
mores_p
Posts: 23
Joined: Sun Oct 28, 2007 11:23 pm
Location: Lafayette, LA, USA.

Re: Left-handed coordinate system in Tracking Tools.

Post by mores_p »

Oops, please ignore my question about "handedness". I found it in "application settings".

However, an answer to "snap" feature would be welcome. ;)

Mark
beckdo
Posts: 520
Joined: Tue Jan 02, 2007 2:02 pm

Re: Left-handed coordinate system in Tracking Tools.

Post by beckdo »

Adding pivot point snap to marker will be added.
kahl_hellmer
Posts: 10
Joined: Fri Sep 14, 2007 7:33 am
Location: Uppsala, Sweden

Re: Left-handed coordinate system in Tracking Tools.

Post by kahl_hellmer »

I find that switching between left- and right handed coordinate system in Tracking Tools works just fine too, but for some reason, no matter what I set in Tracking Tools calibration, I always get left-handed coordinates when I call updateTrackableLocation() and TT_FrameMarkerX-Z(). It doesn't matter whether I load the calibration and trackables files or the project file.

Is the handedness not stored in these files and left-handedness is assumed? How can I get right-handed coordinates?

Kahl
beckdo
Posts: 520
Joined: Tue Jan 02, 2007 2:02 pm

Re: Left-handed coordinate system in Tracking Tools.

Post by beckdo »

Correct. The handedness and other application settings are only stored in the project file.
gkfricke
Posts: 31
Joined: Sun Feb 14, 2010 5:42 pm
Location: Durham, NC
Contact:

Re: Left-handed coordinate system in Tracking Tools.

Post by gkfricke »

For clarification:

When using the Calibration Square:
The marked "axis" Z is the one that flips depending on the selection of Right-handed = TRUE/FALSE in TT application settings, right?
Y is always "up", X is always positive in the direction of the unmarked leg, and Z is NEGATIVE if Right-handed = TRUE or POSITIVE if Right-handed = FALSE?

This is what I *think* I've observed so far, but would like to confirm.

Further observations for clarification, hoping for confirmation:
Yaw is positive rotation about +Y;
Roll is positive rotation about +X;
Pitch is positive rotation about +Z (meaning that when changing from Right-handed to Left-handed, the sign of Pitch rotation also changes, remaining positive about +Z)

Finally, the "snap to marker" mentioned above: is it in the latest version of TT (i.e., 2.1.000 released 2010 Feb 11)?
Birch
Posts: 1139
Joined: Thu Jan 30, 2003 5:00 am
Location: Corvallis, Oregon

Re: Left-handed coordinate system in Tracking Tools.

Post by Birch »

In version 2.1 the following should be possible :

Select a marker that belongs to a rigid body and the option appears in the context menu. Also, it can be reset by right-clicking on a rigid body and resetting the pivot.
iko79
Posts: 11
Joined: Fri Apr 02, 2010 5:31 am

Re: Left-handed coordinate system in Tracking Tools.

Post by iko79 »

[quote=NaturalPoint - Birch Zimmer]In version 2.1 the following should be possible :

Select a marker that belongs to a rigid body and the option appears in the context menu.[/quote]
Is it? Can't find it...
ibrouwer
Posts: 3
Joined: Tue Aug 02, 2011 11:33 am

Re: Left-handed coordinate system in Tracking Tools.

Post by ibrouwer »

I have the same problem as Kahl: the coordinate system in the tracking tools application and Tracking Tools API seem to not be the same, even if they use the same project file: the z-axis is correct in the Tool Tracking application but inverted in the Tool Tracking API.

I choose the default right handed coordinate system orientation in Tool Tracking API, save the project. Then load this project in samples/markers.cpp. When I compare the printed x,y, and z position in the markers.cpp executable with the real-time info in the Tool Tracking application, the z-axis is inverted in the markers executable ( the executable seem to use a left-handed coordinate system even if the project file specifies a right-handed coordinate system ).

Is this expected behaviour?

Iman
beckdo
Posts: 520
Joined: Tue Jan 02, 2007 2:02 pm

Re: Left-handed coordinate system in Tracking Tools.

Post by beckdo »

Unfortunately, you're going to find that the values reported out of the API are always left handed. The handedness toggle in the app only affects the UI.
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