3d adding relative force problems

This is more of a "I don't know something" problem but a problem none the less.

I am making a ball obstacle traverse... thingy game and I want to be able to rotate the camera around and add a force on the ball relative to the CAMERA'S co-ordinate system so there are no errors due to the rotation caused by the ball rolling. Can someone please help???

 

Try Camera.main.transform.forward

 

I'm trying to move the ball, not the camera. I want to rotate the camera and make the ball move, say, forward in relation to the rotation of the camera

 

Yeah this code will give you to current direction the camera is facing in so you can apply that to your ball transform? I think.