Changing movement based on camera direction

Hi

I'm sitting here contemplating a way to solve a rather difficult (to a newbie like myself) problem; I have a script that moves a player around. I also have a camera that can rotate based on mouse movement. However I would always want the forward from the camera to be the forward of the movement for the player. As far as Ive come is to maybe draw a ray from the camera transform and to the player transform. That direction is always the forward direction. Would this be correct? How would I this change the player movement? I have no idea how to tackle it

Code (csharp):

1. var MoveSpeed : float;
2.  
3. function Update ()
4. {
5.     // MOVEMENT
6.     translationVertical = Input.GetAxis ("Vertical");
7.     translationVertical = translationVertical * MoveSpeed;
8.     translationVertical *= Time.deltaTime;
9.     rigidbody.position -= Vector3(0,0,translationVertical);
10.  
11.     translationHorizontal = Input.GetAxis ("Horizontal");
12.     translationHorizontal = translationHorizontal * MoveSpeed;
13.     translationHorizontal *= Time.deltaTime;
14.     rigidbody.position -= Vector3(translationHorizontal,0,0);
15. }

 

You need to convert from the camera's local space to world space. A simple way to do this is by using TransformDirection.

If your camera is looking down you might need to compensate for that, like dropping the y component of the final direction and normalizing it before applying the speed multiplication.

 

Thank you very much Jasper, I now got it working exactly like I want it. In case someone else stumbles upon this post, this is how the movement code ended like. Oh and dont forget to get a reference to the camera (the camera look script is not included as it was not written by me).

Code (csharp):

1.    
2. translationVertical = Input.GetAxis ("Vertical");
3. translationVertical = translationVertical * MoveSpeed;
4. translationVertical *= Time.deltaTime;
5.  
6. translationHorizontal = Input.GetAxis ("Horizontal");
7. translationHorizontal = translationHorizontal * MoveSpeed;
8. translationHorizontal *= Time.deltaTime;
9.  
10. var cameraRelative : Vector3 = theCamera.main.transform.TransformDirection (0, 0, -1);
11. rigidbody.position -= Vector3((cameraRelative.x * translationVertical), 0,(cameraRelative.z * translationVertical) );
12. cameraRelative = theCamera.main.transform.TransformDirection (-1, 0, 0);
13.  
14. rigidbody.position -= Vector3((cameraRelative.x * translationHorizontal), 0,(cameraRelative.z * translationHorizontal) );

 

Very nice. I personally like to move characters as ridigbodies with forces.

Code (JavaScript):

1. var speed : float = 5.0;
2. var movementVector : Vector2 = Vector2(Input.GetAxis("Horizontal"), Input.GetAxis("Vertical"));
3. var force = speed * movementVector.magnitude;
4. var direction : Vector3 = movementVector.y * mainCamera.forward + movementVector.x * mainCamera.right;
5.        
6. rigidbody.AddForce(direction * force);