Unreal Engine Physics Essentials

The 2D and 3D coordinate systems

In Unreal Engine 4, the use of 2D and 3D coordinate systems are used to determine the positions of actors in our game world. In a 2D coordinate system, we can determine an actor's position based on the X and Y axes, left-right, and up-down respectively. In a 3D coordinate system, along with the X and Y dimensions, we can determine the actor's position based on the Z axis: the inclusion of depth.

In Unreal Engine 4, the 3D axes are labeled differently, as displayed in the preceding image. Instead of the "up" axis being the y axis, in Unreal Engine 4, the "up" axis is labeled as the z axis. The "forward" axis is then ...