Interpret results from triangulatePoints

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Hi, I am detecting ArUco Markers with a stereo setup and would like to know the 3d coordinates of the corners. I am using triangulatePoints to achieve that (the rig is fully calibrated and I am calling undistortPoints before triangulating), but I do not understand how to interpret the results. Here is an example:

As you can see the markers are detected fine. The results of triangulatePoints are the following:

0.247877    0.0300715   0.501093
0.254448    0.0923606   0.518614
0.181621    0.0959466   0.508083
0.176167    0.0358917   0.50486

0.00881887  0.0501222   0.502481
0.00898725  0.00313973  0.520062
0.0636986   -0.00419561 0.526967
0.0654933   0.0450242   0.509843

0.166304    -0.163573   0.579394
0.225936    -0.172218   0.58141
0.230371    -0.112224   0.581557
0.170264    -0.104482   0.576754

0.0295858   -0.132247   0.574503
0.0318483   -0.16779    0.591691
0.0783909   -0.178207   0.602229
0.0787127   -0.13994    0.583072

0.151794    -0.236149   0.629165
0.102628    -0.229509   0.624732
0.0989285   -0.286064   0.634169
0.151599    -0.29231    0.637837

I tried to plot these in Matlab, and the result looks good:

But I just cannot find any relations to the cameras position. I would like to have coordinates somehow relative to one of the cameras, so that the camera is the origin of the used coordinate system. How can I do that? I read that the origin is the optical center of the first camera, but then my x-values should not be all-positive, right?