Controlling Camera Rotations Using PCLVisualizer

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PCLVISUALIZER.CAMERA_ QUESTIONS ... Given: camera_ with values clip:0,0, focal:0,0,0, pos:0,0,0, view:0,0,0 .... Rotate camera_ to point in the direction: (1, .75, -2).... Rotate the camera to aim to the left (x direction) 45 degrees relative to its current setting.

What are the formulas for PCLVisualizer.camera_ rotations?

Is there a relationship between quaternions and these four attributes?

What do each of these settings represent?

Right now I have crude approximations of ways to rotate the camera and translate it, but I have not figured out how to aim the camera based on a direction vector. Help would be tremendous...