Unity - How to react to scene picking? How to force select a parent by picking its child in the sceneview

Question

I have the following situation I need an answer to: I have a parent object with children. These children all have unique meshes. Whenever these children are selected in the SceneView, the parent needs to be selected in stead. The children should never have their inspectors exposed (not even a fraction of a second).

How do I do this?

There are two possible solutions that I have come up with which are not the solution I wish to go for.

• First being using [SelectionBase] attribute on the parent object. This work perfectly, but only once. The first time the child is selected, the parent gets selected. However, when I click the child again, it still gets selected.

• Second solution was to react on Selecten.onSelectionChanged. This however is too slow. I can set the selection to the parent if a child gets selected, but the child gets exposed for a few frames still.

Is there an instant solution to this which can guarantee me the functionality of SelectionBase, but then every time in stead of only the first time I click it?

Thanks in advance! :)

Answer 1

I have found a way to do exactly what i want. I combine the [SelectionBase] attribute with a piece of code in the editor OnSceneGui.

• First add the [SelectionBase] attribute to your class

• Second add this code to its editor class

    private void OnSceneGUI()
    {
        HandleUtility.AddDefaultControl(0);
  
        //Get the transform of the component with the selection base attribute
        Transform selectionBaseTransform = component.transform;
  
        //Detect mouse events
        if (Event.current.type == EventType.MouseDown)
        {
            //get picked object at mouse position
            GameObject pickedObject = HandleUtility.PickGameObject(Event.current.mousePosition, true);
  
            //If selected null or a non child of the component gameobject
            if (pickedObject == null || !pickedObject.transform.IsChildOf(selectionBaseTransform))
            {
                //Set selection to the picked object
                Selection.activeObject = pickedObject;
            }
        }
    }
  

This allows the first pick to select the component. From then on, only when you select non-child objects in the scene, selection will actually change.