Unable to rotate GameObject properly?

Question

My GameObject is able to jump towards a moving target (another GameObject), thus adjusting its trajectory - while simulating gravity (as in the .gif).

I want to make the "jumper object" rotate. But I am unable to rotate my GameObject properly. When the GameObject jumps, it doesn't complete its rotation and rotates abruptely. How can I fix this? How can I properly rotate the cube GameObject you see in the .gif? Any fixes are appreciated.

Wanted rotation:

What I get:

Answer 1

The code structure you want:

transform.rotation = Quaternion.Slerp(transform.rotation, targetRotation, lerpFactor);

A more adjusted version for your script:

Change the line

transform.Rotate (new Vector3 (a, b, c) * Time.deltaTime);

with

transform.rotation = Quaternion.Slerp(transform.rotation, Quaternion.Euler(a, b, c), Time.deltaTime);

Also,

        void Update()
        {
            if(Input.GetMouseButtonUp(0))
            {
                //this is only called when button gets relased.
            }

            if (Input.GetMouseButton (0)) 
            {
                //this is called constantly if button is holding down.
            }
        }

---

Edit:

This code piece should do what you want:

    Quaternion targetRot = Quaternion.identity; //try not to modify this directly, or do it, it's up to you.
    bool doRotate = false;
    float lerpLimit = 10; //the degrees you want lerp to stop at. set higher than 0 (i suggest higher than 1)

    public void SetRotationTarget(Vector3 eulerAngles) //call this method to update the rotation target.
    {
        targetRot = Quaternion.Euler (eulerAngles); //building a quaternion from given vector3
        doRotate = true;
    }

    void Update()
    {
        if (doRotate)
        {
            if (Quaternion.Angle(transform.rotation, targetRot) > lerpLimit) //if angle between our rotation and target rotation is not below limit
            {
                transform.rotation = Quaternion.Slerp (transform.rotation, targetRot, Time.deltaTime); //Slerp to target rotation
            }
            else
            {
                transform.rotation = targetRot;
                doRotate = false;
            }
        }

        if(Input.GetMouseButtonUp(0)) //when mouse button 0 is relased
        {
            SetRotationTarget(new Vector3(a, b, c)); //set new rotation target with values of (a, b, c)
        }
    }