Hey, so using Input system 1.3.0, Unity 2021.2.7
The MultiplayerEventSystem is breaking interaction and visual state of buttons contained underneath “playerRoot” objects.
Here’s a video showing the issue:
Basically, when 2+ players are joined. Only the last player is able to navigate and interact with buttons under its associated playerRoot. The first player is unable to interact at all.
Also, the visual state of all buttons seems to be in a constant change between “normal/selected” and “disabled”.
I assume this is because MultiplayerEventSystem manages a CanvasGroup on the “playerRoot” object. And every update is toggling “interactable” which causes nested Selectables to constantly switch between “normal/selected” and “disabled”.
And lastly, if you disable the first player gameObject then re-enable, interaction suddenly works correctly. However, the visual state is still incorrect.
Yeah, it’s going to be a tricky problem to solve. Feels like the Selectable API needs changing to support this functionality.
Something like a SelectableGroup component, that Selectables are aware of and when making navigation choices, they query the SelectableGroup to see if the next navigation target is valid.
The main problem is that the EventSystem was never designed to be used like this. And I’m not sure that even UIToolkit is fixing these issues as well, as that depends on the EventSystem in its current state too. And is the MultiplayerEventSystem even supported in UIToolkit? Since MultiplayerEventSystem requires a root gameObject, UIToolkit doesn’t use gameObjects, so how does that work?
Just helping confirm this situation further. I just posted about it in the 1.3.0 announcement thread. I’ll relay that info to save time for anyone curious.
Selectables coloring settings goes right in the trash. Disabled vs Normal is not obeyed correctly. Almost everything starts showing up as disabled by default. Happens once you have more than 1 PlayerInput w/ their own canvases.
Again, multiple players, multiple canvases: when new Selectables are instantiated on Player X’s canvas, Player Y loses currently selected gameObject in MultiplayerEventSystem and is also unable to navigate back to items in their currently active canvas group.
