Change the rotation of RigidbodyFPController when gravity changed. Please Help!!

Yo!

So I am making a FPS game where player can control its gravity. The Physics.gravity is set to 0 as I want other objects in the scene floating. I am simulating gravity on player by AddForce function. Gravity can be changed in any direction, I am stuck on, when player changes the gravity to be in negative x-axis the player rotates so that its bottom is facing in the direction of gravity(done using animation), the movement of the player gets messy and in-controllable.
I am using the Rigidbody First person Controller prefab of Standard Assets with some minor modifications.

I found these lines in the RBFPController script:

Code (CSharp):

1.                 Vector3 desiredMove = cam.transform.forward*input.y + cam.transform.right*input.x;
2.  
3.                 desiredMove = Vector3.ProjectOnPlane(desiredMove, m_GroundContactNormal).normalized;
4.  
5.                 desiredMove.x = desiredMove.x*movementSettings.CurrentTargetSpeed;
6.                 desiredMove.z = desiredMove.z*movementSettings.CurrentTargetSpeed;
7.                 desiredMove.y = desiredMove.y*movementSettings.CurrentTargetSpeed;
8.                 if (m_RigidBody.velocity.sqrMagnitude <
9.                     (movementSettings.CurrentTargetSpeed*movementSettings.CurrentTargetSpeed))
10.                 {
11.                     m_RigidBody.AddForce(desiredMove*SlopeMultiplier(), ForceMode.Impulse);
12.                 }

Watch the video!

**When I change the gravity to be in -x axis the "Player" rotates and falls, controls go wrong**

 

i think you should make the rigidbody static. Then rotate the camera via code instead of using animation. (i think so, not sure, but that is what i would do instead)