moving player relative to camera.

I have a character controller and i am moving it with the fpswalker script:

moveDirection = new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical"));

moveDirection = transform.TransformDirection(moveDirection);

moveDirection *= speed;

I have made my game to have a camera looking from above, and i want to have the player move the correct way whaever the camera rotation is.

I mean if i press the up key, i want him moving up from the camera's point of view.

Could you help me understand how to change the code above to have it move the way i want?

Thanks!

EDIT bugfixed the normalized.

A (simplified) excerpt from code how I do it (C#):

// we need some axis derived from camera but aligned with floor plane
Vector3 forward = cameraTransform.TransformDirection(Vector3.forward);
forward.y = 0f;
forward = forward.normalized;
Vector3 right = new Vector3(forward.z, 0.0f, -forward.x);

float h = joystick.xaxis;
float v = joystick.yaxis;

Vector3 walkDirection = (h * right + v * forward);

The original code did a .normalized on the walkDirection. The reason you possibly want to normalize is to prevent walking faster when going forward + sideways instead of only forwards (given h == v == 1, length of Vector3(h, 0, v) ~= 1.414, not 1). To prevent this you could add the following:

if (walkDirection.sqrMagnitude > 1f) {
    walkDirection = walkDirection.normalized;
}

If you want constant walking speed (so no slow walking when joystick isn't pressed much) replace the `1f` with `0f`.