In place animations using Mecanim and how to script it

You can easily use Mecanim for in-place movement.

I assume you already have a movement script which lets your character move through the level.

What you need is to expand your movement script with the following (in JS):

 //1. we need access to the animator component which is responsible for mecanim, so declare as a variable:
 private var myAnimator : Animator;
 
 //2. we need to let myAnimator know whom animator component we should use, so in Start():
 function Start(){
  //...
  myAnimator = transform.GetComponent("Animator");
  //...
 }
 
 //3. Now we can access the mecanim variables for example in Update() according how we move:
 
 function Update() {
  //move player with rigidbody.addforce or however you do
  
  //now check in which state the player is and change the mecanim variable:
  //for example if our rigidbody has velocity play walk animation:
  if( rigidbody.velocity.sqrMagniture != 0 )
   myAnimator.SetBool("isWalking", true);
  else
   myAnimator.SetBool("isWalking", false);
 
 }

And don't forget to properly set up the mecanim states: