/// The minimal preparation for use. If these are not set ShowChildLayer() can't work.
 public void Initialize(ConstellationMenuRoot root, AssetTree.Node asset, float scale)
 {
     menuRoot = root;
     menuRoot.MarkGraphDirty();
     menuNode            = asset;
     menuScale           = scale;
     menuOrientation     = transform.rotation;
     menuCenter          = transform.position;
     startPosition       = transform.position;
     savedCameraPosition = Camera.main.transform.position;
     savedCameraRotation = Camera.main.transform.rotation;
     state = IconState.Shown;
 }
        /// Called to make this icon visible and interactable
        public void Initialize(ConstellationMenuRoot root, ConstellationMenuIcon _parentMenu, AssetTree.Node node,
                               Vector3 _menuCenter, float scale, IconState initialState)
        {
            parentMenu          = _parentMenu;
            startPosition       = transform.position;
            startScale          = transform.localScale;
            menuRoot            = root;
            menuNode            = node;
            menuCenter          = _menuCenter;
            savedCameraPosition = _parentMenu.savedCameraPosition;
            savedCameraRotation = _parentMenu.savedCameraRotation;
            menuOrientation     = transform.rotation;
            // Icons are oriented up in world space.
            Vector3    iconToCamera     = savedCameraPosition - transform.position;
            Quaternion rotationToCamera = Quaternion.FromToRotation(-transform.forward, iconToCamera.normalized);

            transform.localRotation = rotationToCamera * transform.localRotation;
            menuScale  = scale;
            background = null;
            state      = IconState.Closed;
            if (node != null)
            {
                // Set foreground icon
                menuItem = (ConstellationMenuItem)node.value;
                spriteRenderer.sprite = menuItem.icon;

                gameObject.name = menuItem.name;
                // Set background icon
                background = new GameObject(name + " Item Background");
                background.transform.parent        = transform.parent;
                background.transform.localPosition = transform.localPosition + transform.forward * BACKGROUND_ICON_ZOFFSET;
                background.transform.localRotation = transform.localRotation;
                background.transform.localScale    = transform.localScale;
                backgroundSpriteRenderer           = background.AddComponent <SpriteRenderer>();

                backgroundSpriteRenderer.sprite = menuRoot.iconBackground;
                if (menuNode.children.Count != 0 &&
                    decorationLabelPrefab != null &&
                    menuRoot.expandableIconDecoration)
                {
                    decorationLabel                = Instantiate(decorationLabelPrefab, background.transform);
                    decorationLabelRenderer        = decorationLabel.GetComponent <SpriteRenderer>();
                    decorationLabelRenderer.sprite = menuRoot.expandableIconDecoration;
                    decorationLabel.SetActive(false);
                }
                menuRoot.MarkGraphDirty();

                float tooltipOffset;
                if (menuItem.tooltipSprite)
                {
                    tooltip = new GameObject(name + " Tooltip Sprite");
                    SpriteRenderer tooltipSpriteRenderer = tooltip.AddComponent <SpriteRenderer>();
                    tooltipSpriteRenderer.sprite = menuItem.tooltipSprite;
                    tooltipRenderer = tooltipSpriteRenderer;
                    tooltip.transform.localScale *= TOOLTIP_SPRITE_SCALE;
                    tooltipOffset = TOOLTIP_SPRITE_OFFSET;
                }
                else
                {
                    tooltip      = Instantiate(tooltipPrefab);
                    tooltip.name = name + " Tooltip Text";
                    tooltip.GetComponent <TextMesh>().text = menuItem.toolTip.Replace('\\', '\n');
                    tooltipRenderer = tooltip.GetComponent <MeshRenderer>();
                    tooltip.transform.localScale = Vector3.one * TOOLTIP_TEXT_SCALE;
                    tooltipOffset = TOOLTIP_TEXT_OFFSET;
                }
                tooltip.transform.SetParent(transform, false);
                tooltip.transform.localPosition = Vector3.up * tooltipOffset;

                tooltip.transform.rotation = transform.rotation;
                SetRendererAlpha(tooltipRenderer, DEFAULT_TOOLTIP_ALPHA);
            }

            parentMenu.childMenus.Add(this);
            lineToParent            = GetComponent <LineRenderer>();
            lineToParent.startColor = Color.clear;
            lineToParent.endColor   = Color.clear;


            UpdateLines();
            SetDecorationLabelAlpha(decorationLabelAlpha.ValueAtTime(Time.time));
            SetBackgroundTransparency(iconBgAlpha.ValueAtTime(Time.time));
            SetRendererAlpha(spriteRenderer, iconAlpha.ValueAtTime(Time.time));

            StartFade(initialState);
            SetColliderSize(0.0f);
        }