Problem with Panda 3d Coordinates

Scripting Issues
1

Hi, I am a newbie in Panda3d. I was learning how to load model and change the camera view. So, I have the following code,

class MyApp(ShowBase):
    def __init__(self):
        ShowBase.__init__(self)
        self.disableMouse()
        self.Box = self.loader.loadModel("Box.dae",noCache=True)
        self.Box.reparentTo(self.render)
        self.Box.setScale(1.0)
        self.Box.setPos(0, 0, 0)

        self.camera.setPos(0, 0, 25)
        self.camera.lookAt(self.Box)

        print(self.camera.getPos())
        print(self.camera.getHpr())
app = MyApp()
app.run()

So, when I run the code, I could see one side of the box. So far so good.
But whenever, I change the camera position to camera.setPos(25,0,0) I found the model has undergone a rolling motion of 90 degree. This implies that the camera went through a rolling motion.
As you can see that I am retrieving camera Hpr, so in the first case the output is LVecBase3f(0, -90, 0), and in the 2nd case the output is LVecBase3f(90, 0, 0).
As per my understanding the camera.setPos should not produce a roll,pitch or yaw motion to the camera.

What I am missing here.
Thanks in advance.

2

Your camera is in position 0, 0, 25 when initializing and looks straight, and the model is 0, 0, 0. That is, the camera is higher than the box. When you call self.camera.lookAt(self.Box) Then she looks at the bottom of the box, for this she needs to turn 90.

3

Thanks That makes sense.