Order of Components on Prefab isn't saved in Unity 5

So before upgrading to Unity 5 I had this item interaction system where you add components on an interactive game object to specify exactly what should happen when the player character interacts with that object (show dialog, switch sprite, give item, .. etc). The ordering of these components (actions) is very important in some cases (when an action delays the execution of the following actions, like with the dialog action).

When I upgraded to Unity 5 I found this weird problem:
When I press the play button, the ordering of the components sometimes changes, and this change is preserved when I stop and go back to editing. This problem doesn't seem to happen on normal (non-prefab) game objects, nor to the ordering of the components inside the prefab itself, it only happens to EXTRA components added after the Prefab is brought to the scene!

I'm guessing this has to do with how prefabs and scenes are saved now in Unity 5, I found this line in the insanely large change log:

So what about modifications to a prefab, where are they stored and how? It seems that the order of EXTRA components isn't saved!
I even forced text serialization and did some diffs, and it seems that whatever reordering I do to these extra components, the files are exactly the same!

I really hope they fix this bug, I don't want to add an "order" property to my action components, it can get messy and I want the order to be clear to the level designers without having to look at numbers!

 

Sorry, I don't have any solution, I just want to add that this happens here aswell, and can indeed be pretty annoying. Hoping UT is having a look into this.

 

I have exactly the same problem. All the extra components on a prefab get reordered after I press play.
It's an annyoing bug, as the only workaround I can think of is to add them during game start through scripting.

 

Thanks for a detailed reply on the topic!

 

So why do I get this problem even when I'm not changing the order of components that are part of the prefab? In my case I am adding components to a MODEL, and like the original poster, the order of the components is important!

Losing references to the model file is a huge pain (if the model file gets updated, everything will be messed up!)

 

Sorry for squeezing in here but it seemed related.. I just tried stacking a simple sequential state machine as mono behaviours and I noticed that if I have multiple instances of a type of component/class..the component order would break when I hit run..

So is it not possible to control the order of components by arranging them in hierarchy on the game object?

 

If component order is crucial to your set-up, one solution would be to add a component to your GameObject that keeps tracks of the order of its components.
Rough idea:

Code (CSharp):

1. public class ComponentOrderList : MonoBehaviour {
2.     public Component[] components;
3. }

The user could drag & drop components in the order they should be in. If it's something you use a lot in your framework, you could invest the time in making a re-orderable list for it. Rotorz would be great for that or if you prefer you can use Unity's internal re-orderable list.
Anyway, then all your class that rely on order would go through the above class to get to the next component in the list. Again, if it's something crucial to your framework, you could make all your classes inherit from a common base class that has a link to the list, kinda like the relationship between components & gameobjects.

 

Hmm... a little sad...the order of components on a game object visually already represent a nice order that is very clear and intuitive..and adding another list where you have to arrange order feels like a case of "don't repeat yourself"

I do have this easy editor script which is using Rotorz. I have to admit that editor scripts are not my strongest side and I was hoping to avoid any gotchas and potential can of worms that might come along by travelling down that route that in the end will become a project of it's own.

In my specify case they would be a stack of different subclasses of an Action Base Class, with all different attributes..

I wonder if it would be possible..to cache the "draw/visual inspector" order in a variable in the base class..then at least the execution will be correct even if the editor visuals get screwed up

 

I agree with you that it feels like it's violating DRY but technically you're not repeating yourself because the component order is something on the Unity side. That's how I'd look at it to make me feel better about implementing this system.