To canvas or not to canvas!

What's the pros and cons of creating canvases for each window-like panel?
Should I implement my all windows as panels in only one canvas or should I create multiple canvases with a panel in them.

 

Sounds like it's a good idea to stress test, I'm guessing canvases have an overhead, whereas their components probably have less of an overhead. So probably easier to have a root object for each group of objects or panels.

 

Seems like this area should be answered by the unity team. It also seems that eliminating child canvas's could be in the unity spirit of keeping things optimised behind the covers might be worth considering?

 

According to what Unity has said, you should group as much as possible that is static (not being resized/animated/replaced regularly) in one or few canvases to encourage batching, and move volatile elements to their own canvas(es) so that as little recalculation per frame is happening as possible, but only if you are experiencing performance issues.

 

So, it looks like that we should use separate canvases for such windows which can be moved or resized...

 

Where did Unity say this?

 

They had a "hangout" last week. It should be on the Unity YouTube channel.

 

In my head a UI Group that is linked to, but not part of another should be it's own canvas, especially if it replaces the first after a click or what not. I have zero idea about performance though.