How do I make a camera bob when I walk?

Originally based on this one, I made another script in C# which requires CharacterController and CharacterMotor, just drop it into the child camera and you should be set to go. I hope this is of use to someone. Cheers, using UnityEngine; using System.Collections;

 public class HeadBobbing : MonoBehaviour {
 
 
 // drop into the main character's camera
  // editor-accessible vars
  public float bobbingFreq = 1.8f; // in Hz, TODO make it dependent on speed
  private float bobbingFreqCached;
  public float bobbingRatio = 0.08f; // as a factor of character height
  
  // non editor-accessible
  private float phase = Mathf.PI;
  private CharacterMotor characterMotor; // we need to see if the character is walking or jumping (TODO maybe running and sliding)  
 
  private CharacterController characterController;
      
  private float height; //we'll need this for bobbing as a function of height
  
  private float bobbingAmount;
  private float heightDependency;
  private float currentBobbing; // keep track of y axis modification 
  private float bobbingDelta; // how much has bobbing changed in the last frame
  // Keep a mask for the displacement states where isWalking is xxx1 isStepping xx1x and isStopping x1xx
  private int stateMask = 0;
  private const int isWalking = 1; 
  // this next variable can be useful for triggering stepSounds, see getter below
  private const int isStepping = 2; 
  private const int isStopping = 4;
  // need to remember where camera was before we began toying with it. 
  // NOTE this wont work if anything else is moving the camera!
  private Vector3 OriginalCameraLocalPosition;
   
  void  Start (){
      characterMotor = GetComponent<CharacterMotor>();
      characterController = GetComponent<CharacterController>();
      height = characterController.height;
      OriginalCameraLocalPosition = Camera.main.transform.localPosition;
      
     heightDependency = transform.localScale.y * height / 2;
     currentBobbing = 0.0f;
     bobbingFreqCached = bobbingFreq;
  }
  
  void  Update (){ 
     bobbingAmount = bobbingRatio * heightDependency;
     if ( (characterMotor.inputMoveDirection != Vector3.zero) && characterMotor.IsGrounded() ) { 
         UpdatePhaseAndBobbingDelta();
         stateMask = stateMask | isWalking; // isWalking = true;
         stateMask = stateMask & ~isStopping; // isStopping = false;
     } 
     else {
         // bobbingDelta = 0.0f; // see note in our first branch
         if( (stateMask & isWalking) > 0 ){ // if we got here, we're stopping
             stateMask = stateMask | isStopping; // isStopping = true
             UpdatePhaseAndBobbingDelta( (phase > 0) ? 1 : -1 ); // if our phase is less than 0, rewind it
             if ( (stateMask & isStepping) > 0 ) {// we're back down
                 Camera.main.transform.localPosition = OriginalCameraLocalPosition; // avoid cumulative errors
                 stateMask = stateMask & ~isWalking;
                 phase = Mathf.PI; // ready to start again
             }
         }
         else {
             bobbingDelta = 0.0f;
             stateMask = 0; // we're not doing anything
         }
     } 
     Camera.main.transform.Translate(Vector3.up * bobbingDelta, Space.World);    
  }
  
  // by default we add phase but it might be shorter to rewind it when stopping 
  private void  UpdatePhaseAndBobbingDelta (){
      UpdatePhaseAndBobbingDelta( 1.0f );
  }
  
  private void  UpdatePhaseAndBobbingDelta ( float direction  ){
 
      float twoPi = Mathf.PI * 2;
        // bobbing happens here, add one to Sin to avoid going under the terrain
        float previousBobbing = currentBobbing;
        currentBobbing = (Mathf.Cos(phase) + 1.0f) * bobbingAmount;
        bobbingDelta = currentBobbing - previousBobbing;
        // update phase in a frame-independent fashion
        phase = phase + (direction * (twoPi * Time.deltaTime * bobbingFreq));
        // wrap phase
     if (Mathf.Abs(phase) > Mathf.PI) { 
         phase = phase - (direction * twoPi); 
         stateMask = stateMask | isStepping;
     } 
     else
         stateMask = stateMask & ~isStepping;
  }
     
  public bool getIsStepping(){
     return ( (isStepping & stateMask) > 0 );
  }    
 }

it is working when jumping too, should be solved, work work work :!