Smooth rotation broke my head.

I've tried almos all the ways to make my rotaion smooth with no luck;
I have a capsule collider with rigidbody. I want to make a simle fish behavior with jump from the water and fall back.

Jump:

Code (csharp):

1. if(Time.time > JumpDelay)
2.         {
3.             JumpDelay = Time.time + JumpRate;
4.             rigidbody.AddForce(Vector3.up*jumpForce, ForceMode.Impulse);
5.         }

rotate to move dir

Code (csharp):

1. transform.up = rigidbody.velocity;

How to smooth?

 

You can use this to set the rotation based on the velocity

Code (csharp):

1.  
2. transform.rotation = Quaternion.LookRotation(rigidbody.velocity);
3.  

To rotate smoothly, you can use Quaternion.RotateTowards like so

Code (csharp):

1.  
2. Quaternion toRotation = Quaternion.LookRotation(rigidbody.velocity);
3. transform.rotation = Quaternion.RotateTowards(transform.rotation, toRotation, Time.deltaTime * yourSmoothingValue);
4.  

 

Im newby, but found yesterday those tutorials, maybe you find the answer there..

Slowly rotates towards the target:
http://unity3d.com/learn/tutorials/modules/intermediate/scripting/quaternions

Smoothly locate with Lerp..
http://unity3d.com/learn/tutorials/modules/beginner/scripting/lerp

Maybe it helps..

 

I've tried this way, and it won't rotate properly.. The camera is looking from the side with positive Z -> right. I need to rotate my fish in negative, or positive X axis.