Add force in the camera direction??

I want to addforce in the direction that the camera is facing. The only problem is that the camera is slightly pointing down. So if I go backwards, the ball starts the float a little. I am currently using: `var moveRelativeVerticalRaw : Vector3 = camera.main.transform.forward * Input.GetAxis("Vertical");` `rigidbody.AddForce(moveRelativeVerticalRaw / 2, ForceMode.Impulse);` but again this adds force in the camera's tilted direction :( So basically, I guess how would I make it so that the force applied is parallel to the ground?? or, is there any other way of doing this?