How to keep the velocity of a rigidbody2d while changing its direction according to rotation?

Questions & Answers
1

For the last few days I’ve been trying to have a rigidbody2d rotate while keeping its current velocity only changing where the velocity is directed. After some research, this is what I’ve come up with:

            var v:float;
		    v = rigidbody2D.velocity.magnitude;
       	
       	var cos=Mathf.Cos(gameObject.rigidbody2D.rotation);
       	var sin=Mathf.Sin(gameObject.rigidbody2D.rotation);
       	
       	var unitvector : Vector2;
       	unitvector = Vector2(cos,sin);
       	unitvector=unitvector.normalized;
       	
       	var x : float;
       	var y : float;
       	
       	x=unitvector.x;
       	y=unitvector.y;
       	
       	gameObject.rigidbody2D.velocity=Vector2(x*v,y*v);

However, this only makes the object stand still in the air slighty wiggling back and forth when I press the key. What’s wrong with my solution and how can I fix it?

2

If you want to keep the velocity constant no matter what direction it is facing or turning, add the following line in FixedUpdate():

 rigidbody2D.velocity.magnitude = rigidbody2D.velocity.magnitude.normalized * someSpeed;