+Z is forward? Huh? I thought -Z is

I saw in a Physics thread a JME core developer state that +Z is forward and that doing things otherwise would cause great difficulty.

I have been working with -Z forward, +Y up, +X right for a full year. I feel this is fully conformant with slide 7 of the “JMonkeyEngine3 Math for Dummies” tutorial which states plainly on slide 7 that +Z faces TOWARD YOU, i.e., backwards.

While I know that these are simply conventions, I know, too, that defying those of your platform can cause a lot of mysteries and frustration.

Can someone in the know answer these questions in the JME3 gestalt?

What is left? +x or -x?
What is up? +y or -y?
What is forward? +z or -z?


left is -x
up is +y
forward is -z

Now, If you rotate your character, having it look like going forward might be going +z… not sure this line was useful :D.

My understanding, in view space (ie: screen space) +x is right, +y is up, +z is towards you (out of the screen).

In object/quaternion space, +z is forward so -x is right, etc… This is more of a convention if you want to be compatible with other things that use orientation relative to a mesh. For example, if you want to know what direction to move forward then you rotate UNIT_Z by the object’s rotation. Left is UNIT_X, up is UNIT_Y.