Great stream, and thanks for getting to my question. Looking forward to the next one
Yep, also enjoyed it. Hope to see these in a continuous fashion!
You can use Behavior Trees right now! More improvements to the system are in progress, and documentation is also in the works right now.
While the Behavior Tree system is considered “Experimental” currently, that does NOT mean it won’t be backwards compatible! We’re using Behavior Trees for AI on Fortnite, and we certainly wouldn’t want to have to redo all of the work we’ve done there. I can’t promise there won’t be some significant changes (we have some plans for more improvements, and it’s possible that some of those will require a bit of refactoring). However, the system is pretty far along and is getting closer to leaving the “Experimental” category. We’ll certainly work to minimize any changes end users have to make; we ARE some of those end-users.
I can’t give a timeline for when the “Experimental” label will be removed, but we will have documentation sooner. (We wouldn’t be working on documentation though if we weren’t closing in on it being “not experimental”.) Regardless, you shouldn’t let the “Experimental” label stop you from using the feature. 
I’ve started posting a little bit here: Behavior Tree Documentation In Progress
I hope to have more updates in the near future; there’s also many other threads on the Forum and AnswerHub.
Thanks for the stream, you guys are awesome! 
Definitely like the idea of once-per-week streams answering some of the most popular/critical questions/problems.
Missed It 
Hey guys,
Whats the turn around for when your twitch sessions get uploaded? Being in Australia makes it hard sometimes to be around when you run day sessions. Not in a hurry but from the sounds of it this session was a great information bucket to watch 
Loving your work so far
I think twitch automatically records every session, so you might be able to find the recording in a “Previous Recordings” page (could be worded differently, can’t check myself as I’m on restricted internet at the moment).
Not sure on how long after the stream it is uploaded, but keep checking back and I’m sure it’ll show up in the next few hours.
Hey guys. I think this is great. Not only did you guys go open source but also are opening the doors of your company! It is great to see the faces behind such great work. I believe that you are changing not only game development but gaming in general. Please keep making these broadcasts! Please keep changing the world at such epic levels!
What time is that in GMT ? 
We in europe want to watch too :3
That was yesterday 
Oh D: Too bad :Z
Not to worry, they mentioned it will be available on youtube for those who missed it
Just a heads up to those who missed it, the full stream and any previous streams can be viewed on the Past Broadcasts page, streams get recorded in full automatically by twitch, but comments won’t be visible.
to be honest i found the last livestream rather boring. it was just the two guys talking about the engine. it would be far more interesting to have say showcases of peoples works, going over a certain engine feature, giving us some example, more hands on stuff rather then just sitting around talking and showing nothing of the engine. That really seems like a waste, plus honestly it would be a good way to show off the engine to people who are interested in it. I really found the livestream really boring and it was mostly just an hour of the two guys sitting around and talking. Thats not interesting. the Q and A is nice but still.
please really work on making your livestreams like this much more interesting its about unreal engine 4. show off some of the things within the engine, provide tips and tricks, maybe a “tutorial of the week” or something ,
because a live stream about a game engine where two guys just sit and talk the whole time and thats it.
really is not interesting at all.
Just saying :-p.
I really enjoyed this video! I am new to Unreal Engine and this sort of loose conversation is perfect for understanding what the company values and where it is headed. I think it’s endearing to hear you guys wax poetic about the BBS and MUD era. All these details are what ultimately made Unreal what it is today, so I find it extremely interesting.
Please have more ‘meandering’ videos like this in the future! The candid nature of the talk coupled with Ray and 's enthusiasm instilled a lot of trust and excitement for the future of Unreal Engine