How to use quaternions coming from ros? I have a quaternion coming from a ros tf tree that is representing the orientation of my camera. I am trying to set these values for a blender script to render a scene, but the camera looks into the wrong direction, compared to when I visualize the quaternion within rviz(ros visualization tool). So I assume there is some fixed rotation that I need to apply between the tf exported quaternions and the beldner quaternions, but I'm not sure which one. Example pictures will make clear what I mean:

The box I'm trying to render is where box_corner_tracker is


The camera in rviz looks along the z(blue) axis. The perspective here is slightly changed, but imaging the box being there where the camera frame is looking with the z(blue) axis.


Now when I enter some example values into blender you can see that the camera look completely into the wrong direction:

The tooltip in blender for quaternions says wxyz am I right to assume that this is the order the values need to be entered(I did it this way)? 

I'm not sure what the problem is but I assume that my question is what is the transformation between the looking direction of the blender camera and it's z-vector?
If you have a look at any camera in Blender with local transformation orientation selected, you will see that in Blender cameras look at negative z direction, up is positive y and right is positive x:
  

You will need to match whatever camera orientation is used in the software you are importing from. It might even be that some axis is inverted in another software.