Z-coordinate has to be 1 or -1

edit

Hello,

I'm starting to build a map using gmapping, but whenever I start slam_gmapping, the following warning is shown:

Laser has to be mounted planar! Z-coordinate has to be 1 or -1, but gave: 0.00000

This is one of the published transformations:

<node pkg="tf" type="static_transform_publisher" name="link2_broadcaster" args="0 0 0.1 0 0 0 1 base_link camera_link 100" />

When I change the X argument into 1 or -1 the warning is gone! I don't know why!.But I'm sure there is something wrong!! and I need the X to be 0.

any idea?

UPDATE:

These are the frames in rviz:

and I cannot change the values of the orientation in rviz.