ofxAruco and multiple kinects

Hi,
I’m trying to calibrate multiple kinects using ofxAruco.

(Multiple Kinect setup for real time volumetric reconstruction and tracking of people) says "Don’t bother physically measuring if you need things to actually line up. Since the Kinects will be opposed, you could use a calibration object, such as a large cube with a different AR marker on each face. Write something (using AR Toolkit or whatever is more popular now) to recover the 6 DOF transformation matrix when it sees the marker, and you will know the scale from physically measuring the cube. When Kinect 1 sees Face 1 and Kinect 2 sees Face 2, you can then get the Kinect 1 -> 2 transformation matrix by combining the individual measurements plus the physical offset of Face 1 to Face 2. "

I think I understand the above method. This is my understanding:

I am trying to figure out how to align my two point clouds from my two kinects using the AR boards. To do this I am trying to get a 4x4 matrix that represents the translation/scaling/rotation needed to move from camera A’s perspective to camera B’s. I then want to use that 4x4 matrix to translate/scale/rotate all the points in camera A’s point cloud so that they line up with camera B’s point cloud.

I can detect the AR board. I then call ofxAruco::getModelViewMatrixBoard(). This returns a modelview matrix. My understanding is that this modelview matrix describes the position of the AR board relative to the openCV camera. The openCV camera is calibrated with CameraParameters::readFromFile() and camParams.glGetProjectionMatrix() will give me a projection matrix for that camera view.

According to (http://answers.opencv.org/question/23089/opencv-opengl-proper-camera-pose-using-solvepnp/), the modelview matrix is from “model’s frame (ie the cube) to the camera’s frame (it’s called view matrix).
The camera’s frame are not the same in opencv and opengl. Y axis and Z axis are inverted.”

What I am wondering, is does ofxAruco take the fact that opencv and opengl use different cameras into account when you call ofxAruco::getModelViewMatrixBoard()? Is the modelview matrix returned already converted to opengl’s camera’s frame?

The other thing I am wondering: is there an easier way to do this? Has anyone else done this before? I’m learning a lot about projection matrices and modelview matrices and stuff which is nice but at this point I’m starting to worry I won’t be able to figure this out.

Thanks in advance!