Rotating an GameObject in a 2D plane based on clicking on a game object.

Questions & Answers
1

Hi,

I have been trying to solve a problem for a while and I feel like I am going in circles, so I thought I would try here.

Firstly, I apologise for the crudeness of the image.

I have a Circle (Blue) with a Game Object in the center of it (Black Circle). The Camera (Green) is a child of the Black Circle.

I am trying to rotate the camera, to the randomly instantiated Game Objects (Red) When they are selected, by rotating the Black Circle, however, I am running into difficulties when the Black Circles rotation value goes into negative values.

I haven’t had great success with this so any help in pointing me in the right direction would be much appreciated.

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118931-bad-image.png512×512 15.4 KB

2

Hi, so I managed to get something working very close to what I wanted, I think I can tune it in from here.

But I wanted to share my solution so here it is:

if (Input.GetMouseButtonDown(0))
        {
            // Getting Camera.
            Camera myCamera = Camera.main;
            // Get parent Transform from camera
            Transform cameraRotator = myCamera.transform.parent.transform;

            // Get positions of the building in question and the cameraRotator.
            Vector3 currentPos = cameraRotator.position;
            Vector3 targetDir = transform.position;

            // Subtracting the Vector3's from each other.
            Vector3 relativePos = targetDir - currentPos;

            // Create the Quaternion we need to rotate by. 
            Quaternion rotationDelta = Quaternion.FromToRotation(cameraRotator.transform.up, relativePos);
            
            // Nuke the Y and Z Axis back to zero on the delta
            var angles = rotationDelta.eulerAngles;
            angles.y = angles.z = 0f;
            rotationDelta = Quaternion.Euler(angles);
            
            // Multiply the values together.
            Quaternion targetRotation = cameraRotator.rotation * rotationDelta;

            // starting the routine that will allow us to lerp this aforementioned value.
            StartCoroutine(Transition(cameraRotator, targetRotation));

        }

IEnumerator Transition(Transform cameraRotator, Quaternion targetRotation)
    {
        float step = 0.0f;
        while (step < 1.0f)
        {
            // The step size is equal to the speed times frame time.
            step += Time.deltaTime * (Time.timeScale / transitionDuration);
            cameraRotator.rotation = Quaternion.Lerp(cameraRotator.rotation, targetRotation, step);
            yield return 0;
        }
    }