* Still to do:
* Properly handle effects (disable 3D effects) for layers
* Handle hot reloading properly
* Avoid duplicating the configuration of the custom object inside each object created from it. Instead, only store the modified values.
* Add a "Extract as a custom object ("prefab")" when selecting instances in a scene.
* Add a dialog to give choice between 2D or 3D object when creating one.
* Make sure "behavior shared data" are properly handled (physics, pathfinding...)
* Check if we need to give an expression to translate coordinates from the parent to the local custom object.
* Ensure a deleted custom object does not break the editor
Co-authored-by: Davy Hélard <davy.helard@gmail.com>
- Global or scene variables can be used with a unique action and condition.
- Object variables can be used with a unique action and condition.
- Variables need to be declared following the same logic as the new expression syntax.
- Local variable can be declared on events
- Extensions have their own variables
- Show a diagnostic report when a preview is launched and there are missing scene variables, object variables or behaviors.
- This is especially useful if external events are shared between several scenes.
* This allows [custom behaviors](http://wiki.compilgames.net/doku.php/gdevelop5/behaviors/events-based-behaviors), that you can create in your project or get from extensions, to require the presence of one or multiple other behaviors on an object.
* This is an advanced feature that is helpful to create behaviors that are based on other. For example, a behavior "Platformer enemy" using the "Platformer object" behavior and adding specific actions, conditions and logic to make an enemy chase the player.
* If you create a behavior and want to use this, just go to the properties of this behavior and add a new property. Choose the type "Required Behavior" for this property. You can then use this new behavior in the events of the behavior you just edited.
* To use a behavior based on another, you don't need to do anything special! Just add it to your object as usual: any missing behavior will be added to your object, so you can start using it immediately.
