Coordinate System
Left-handed and right-handed coordinate systems
In the three-dimensional coordinate system, there are generally two representations: left-handed coordinate system and right-handed coordinate system. The two coordinate systems exist because they are represented differently in different systems.
In recognition, we can find out by looking at the orientation of the hand, the thumb is the x-axis, the index finger is the y-axis, and the middle finger is the z-axis.
Left-handed coordinate system:
In the Unity world, model space and world space are left-handed.
Right-handed coordinate system:
Different from the left-handed system, the positive z-axis of the right-handed system points out of the screen, and the observation space uses the right-handed system.
The positive direction of rotation is also different in the two coordinate systems:
In a left-handed system, the positive direction of rotation is clockwise, while in a right-handed system, the positive direction of rotation is counterclockwise.