One of the most basic and at the same time important issues when working in 3D is that different applications use different conventions when it comes to Orientation.
Godot uses an orientation in which the Y axis is oriented from top to bottom. That is, if we look at the axes, if the X axis is the one that is oriented from right to left, the Y axis is the one that is oriented from top to bottom and the Z axis is the one that is oriented from front to back.
Other very popular 3D applications use other orientations, normally in which the Z axis is the one that points from top… more