Unity UI On GameObjectPostion

 

void DrawTest()

    {

        // Offset position above object bbox (in world space)

        float offsetPosY = target.transform.position.y;

        // Final position of marker above GO in world space

        Vector3 offsetPos = new Vector3(target.transform.position.x, offsetPosY, target.transform.position.z);

        // Calculate *screen* position (note, not a canvas/recttransform position)

        Vector2 canvasPos;

        Vector2 screenPoint = Camera.main.WorldToScreenPoint(offsetPos);

        // Convert screen position to Canvas / RectTransform space <- leave camera null if Screen Space Overlay

        RectTransformUtility.ScreenPointToLocalPointInRectangle(MainCanvasRect, screenPoint, null, out canvasPos);

        // Set

        imageRectTransform.localPosition = canvasPos;

    }