How does Sketchup determine Camera height?

I am trying to set up a sand box environment for studying perspective.

I’ve run into an issue with Sketchup’s camera tools though. When you create a new camera (ACT) how does Sketchup determine its actual .0 (Meters) height?

I though it was the at the exact point of the Axes origin but its not.

For example, if I create a new camera at a height of 6 meters and then later on choose to go > Edit Camera and dial in 0 for height, it just gets moved to some random area.

Where is that 0 point? how do I change it? for example set it to the Axes origin?

Thank you

You can set an exact point of view in SU. Use the position camera tool, you can visit a link to see more about Walking through a Model | SketchUp Help