Embed Notice

2D games often had +Y down instead of up. This is because the screen is drawn from the top left corner to the bottom right corner. And by screen draw I mean, how old CRTs used to draw the image.

I have no idea why +Y is up in 3D games. Probably because OpenGL did that? Someone must have done that first and everyone copied it.

The standard should be left hand, +X is right, +Y is forward, +Z is up.