Convert Input.mousePosition to RectTransform pivot position

Hmmmm... I tested it now, and it looks like it works for me. So perhaps you have a different setup then I do in my test, or misunderstood me, or I misunderstood you :p

But this is the code I currently have in my test. It prints out the normalized position. (It does clamp it between 0 and 1 though, cause thats how Rect.PointToNormalized works)

 public class PivotTest : MonoBehaviour
 {
     private RectTransform rectTransform
     {
         get
         {
             return transform as RectTransform;
         }
     }
 
     void Update()
     {
         Vector2 localpoint;
         RectTransformUtility.ScreenPointToLocalPointInRectangle(rectTransform, Input.mousePosition, GetComponentInParent<Canvas>().worldCamera, out localpoint);
 
         Vector2 normalizedPoint = Rect.PointToNormalized(rectTransform.rect, localpoint);
 
         Debug.Log(normalizedPoint);
     }
 }

Hmmm... I tested it with screen space overlay and it worked for me... So I started to test it now, and realized that it might be because you have the rendercamera of the canvas set.

Normally, you can only set the render/event camera when you select 'screen-space camera' or 'world space'. But it remains set when you then switch back to screen space overlay. I didn't expect that :p

ScreenPointToLocalPointInRectangle requires a camera as parameter, I use the render camera for that as it is in most cases the correct one, when in screen space overlay, this camera should be null, I expected worldCamera (thats how the render camera in the inspector is called in code) to be null when you switch to screen space overlay but it turns out it isn't :p

What I think that's happening is that you still have the render camera set. (switch to screen space camera, set camera to null and then switch back to screen space overlay to see if it is fixed... Alternatively, replace 'GetComponentInParent().worldCamera' with 'null' :p