Which axis represents depth for a camera?

In a 3D space, the axes typically represent different dimensions. The X-axis usually corresponds to horizontal movement (left and right), the Y-axis represents vertical movement (up and down), and the Z-axis is designated for depth (forward and backward).

When a camera is placed in a 3D Unity scene, it uses these axes to determine how it will view the world. Specifically, manipulating the Z-axis will move the camera closer to or further away from objects in the scene, effectively changing the depth perspective. Thus, for a camera, depth is represented by the Z-axis, which directly affects how objects are perceived in terms of distance from the viewer’s point of view.

In contrast, the other axes do not serve this purpose; while the X and Y axes manage the horizontal and vertical placement, they do not provide depth information. The W-axis typically represents additional dimensions in specific mathematical contexts and is not used to symbolize any depth in standard Unity 3D camera terminology.