An alignment axis is a line that is used to align an object in space.
There are three alignment axes: the vertical alignment axis, the horizontal alignment axis, and the axial alignment axis.
-A vertical alignment axis is parallel with gravity and aligned perpendicular to the ground plane, so it always points up when you stand on your head or down when you stand on your feet.
-The horizontal alignment axis is perpendicular to both gravity and Earth’s surface; if you place an object between two people standing at opposite ends of a room, its horizontal alignment will point towards one person or the other.
An axial alignment axis goes through both sides of an object, like a pole running from top to bottom or front to back. They are typically drawn through the center of mass and can measure symmetry in things, such as a person’s face. It’s a very useful tool.