How Forza's Racing AI Uses Neural Networks To Evolve | War Stories | Ars Technica

[@anotheruser8105]

This is one of the BEST series on the internet

[@dinospumoni5611]

It really is, riveting content and maybe the best direction/editing on all of KZbin,

[@gothmuffin666]

I love how dense this is with information, I don't even play racing games and that was a treat

[@StevenCasteelYT]

He did a great job walking us all through it. I love how bleeding edge video game stuff overlaps in so many tech areas.

[@well_as_an_expert_id_say]

Play forza horizon, it's not the typical racing game my friend. It's open world, and beautiful. Go explore Scotland

[@u2bemark]

agreed.. when I hear people like Dan Greenawalt speak l think.. man, if I ever need a guy as creative director for.. well, anything.. I need a guy that LIVES AND BREATHES the content like that guy. He's like the polar opposite of an "empty suit".

[@ALiberalVeteran]

Agreed, im not even a big racing game fan but i am a simulation fan and its such a fun game

[@Jourmand1r]

everything they say in this video is lies.

[@chris-hayes]

Never imagined games would be running simulations to inform AI at the load screen, pretty impressive.

[@danarose2677]

I had a buddy who's told me he hated seeing my drivatar. Much like me, it would wait until a third of the race and then start moving up the feild and would end up running him down the last 2 laps.

[@psychowordsmith]

That's awesome. Trolling your friend in your sleep

[@drkbob]

Sometimes you can't even imagine the amount of work behind the game you're playing. This was interesting af.

[@foleamaria3292]

It's cuz it's fake

[@ashutoshbaluni3188]

@@foleamaria3292 hmmm yes, this game is indeed fake. forza doesnt even exists, dunno y ppl are making such a fuss abt this smh

[@vincentjohnflorio]

@@ashutoshbaluni3188 My reply is fake as well. It's a conspiracy!

[@Szioul]

That Turn 10 Studios intro clip at 1:50 is way too quiet.

[@Jack2421992]

hahahaha

[@fairulmonstarz]

lol

[@Nismoronic]

Szioul I feel that

[@Marc28031984]

THAT was easily one of the most interesting, Forza related content I’ve seen...ever!

[@GradyLorenzo]

We don't deserve Dan. Honestly one of the most wholesome people in the industry.

[@BlueZirnitra]

Oh I'm sorry I'll switch over then.

[@AlternativeImpulse]

@@BlueZirnitra What does this even mean you weirdo

[@jsonuk]

It's SUPER interesting how they built it from the ground up and put layers upon layers to get todays results. The neural network stuff is especially fascinating and blows me away how early they were experimenting with that. I just love the detail about the in depth thinking behind solving these complex problems - and how its still an ongoing process. I've hardly played any of this franchise, but I am in awe of their work. I am a programmer, and this ticks the boxes about everything I love in programming. Amazing ⭐️

[@HinanawiTenko]

Listening the the explanation on Chap 3 actually explains why on some PCs, mine included, FH4 stutters here and there during track load. Its running simulations.

[@WynnofThule]

"It did things we didn't expect" he says as the AI Charles Leclerc's itself straight into a tire wall

[@DanArnets1492]

That's a Formula E car, not a F1 car

[@VIctorAbicalil]

2 years later and this comment has definitely aged like fine wine.

[@chris-hayes]

Didn't expect a technical discussion about AI from a creative director. Loved the discussion about drivatars doing unexpected things and hearing exactly why they're doing that. To a player it makes zero sense, with a neural net I can imagine it makes about as much sense to the devs as well.

[@agusglauber]

This video is amazing. So interesting! Never stop this series!

[@BrandonTylerGoogle]

Dan Greenawalt is smart guy and a great communicator. Could listen to him all day talk about this tech. Very cool. Thanks for sharing!

[@vomithaus1]

I have never understood why they don't allow AI to mess up the way humans do. This would reduce or eliminate the need for rubber banding because you would stay in the race in hopes that your opponent may make a similar mistake. I recall turning laps all by myself in Grand Prix Legends with no AI around me and loving it. The joy of driving was there to entertain. Keeping a pack of cars around you by artificial means creates a predictable, boring situation.

[@AmrishGamer]

That was so much interesting

[@ilikmlow6900]

AI drivers randomly braking makes so much sense now

[@ErebosGR]

Also, AI hitting cars as if they don't know they're there. Or being unable to find their way into the pit lane, or from the pit lane back to the track etc. etc.

[@SlevinKalevera]

So glad I stumbled onto this. I've been watching Dan for YEARS at e3s and such. Hearing him really deep dive into this passion project that is HIS life... Man. Thank you for this

[@reallydeej]

Best war story yet!

[@michaeltenbroeck1807]

AI is like a 2 year old. Priceless! Love you Dan. Thanks for all you do.

[@FSX239]

So deep! More of this!

[@darrenharper609]

People who claim there's nothing wrong with Forza Drivatars should be forced to watch this. It proves once and for all just why it's broken.

[@HelderP1337]

Fascinating stuff man, wasn't excepting such a deep dive on AI.

[@daithiocinnsealach1982]

Just started playing Forza this year. Horizon 4. Bought 3 just before it went off sale forever. Incredible games. Lots of moaners though. This video helps explain the difficulties (I intuitively knew must exist anyway) that many players experience with the Drivatars. I'll pass it on if I come across any more of them.

[@AynenMakino]

I really love how in-depth this episode is!

[@JokerJay1990]

If I could hook war stories up to my frekkin veins and never leave my bathroom, I would totally do it. Thank you ars technica you give me hope for a better future.

[@quinten9007]

I'm very concerned that this man puts peanut butter on everything

[@BrandonTylerGoogle]

Ha! Finally got to that point of the video 27:19

[@psychoyuri3283]

@@BrandonTylerGoogle haha lmao nice found

[@fairlydecentshow]

This guy worked on more of my favorite games than anyone else! Midtown Madness was great! How I miss the good old times!

[@PayneDeathz]

Please keep making these series Ars Technica! This is way better than my uni lecturer!

[@isatche]

Forza Horizon 3 is one of my all time favorite games. I'm grateful for this insight, it made me appreciate the game on a whole new level.

[@nickinportland]

We don’t have these kind of existential questions on my good old 3DS

[@JoshuaJayMyers]

I really like this guy. He has a humble vibe and Im glad to know he is a part of a franchise I love so much.

[@munkytaint666]

i do understand why players want rubber banding but i hope FM8 will have an option for us to toggle it off if we'd prefer to play without it

[@xavilend]

New war stories, instant like!

[@wedusk]

Really digging this series. I came across the drivatar system way back in a GDC PowerPoint I think and was totally fascinated by it. Of course I was way too young back then to understand it. Now as an engineer, it blows my mind.

[@rjspires]

I hear him neural network, I start thinking SkyNet. Just mind blowing the work that went, & still going into tech behind AI.

[@kyle8851]

This is a great video! I love looks like this into how games work behind the scenes and all the thought that goes into creating them. Thanks so much for this deeper dive into a franchise I've fallen in love with!

[@FintanMoloney]

Incredible to hear an explanation of how everything works behind the scenes of the Forza series. Very interesting information here.

[@RyTrapp0]

Really appreciate Dan's candor here. The "sim racing" community(uh oh, already gonna ruffle some feathers by insinuating that 'Forza Motorsport' is a sim racer...) is fickle, reactionary, and disgustingly ego driven to the point that having legitimate discussions about why a *game* needs certain "controversial" features is just an impossibility. Actually talking about the implementation of some degree of 'rubber banding' is a bit ballsy when there are those who will no doubt have an overreaction to this "admittance". The reality is that most "sim racing fans" aren't actually capable of being honest about what they want - the old [probably not actually real] Henry Ford quote of "...if I asked my customers what they wanted, they would have asked for a better horse" - and, contrary to the way that community acts, they DO in fact want to be able to have this thing called "fun". 'Forza Motorsport' has been incredible since day one - I STILL remember playing the demo from Xbox Magazine like a month before the game's release(they stole my heart with the 1999 Dodge Viper ACR at Laguna Seca!!!). Every iteration in the series may not have been perfect, but the series really did change racing games as we know them; not only did we get to really modify the cars in a meaningful way, but we actually got VISUAL MODS for a change too, not to mention engine swaps, power adders, etc. GOOD TIMES!

[@sp3cterproductions]

It's really exciting to see upper management that actually understands the project fundamentally.

[@ardonjr]

17:25 "There is a Bugatti Veyron on the track"... ArsTechnica starts showing a Bugatti Chiron :')

[@CRUDEDriving]

I own and play all the Forza's, and have always had a love/hate relationship with them but for the most part I thoroughly enjoy them on my wheel setup and controller. This awesome video just gave me an even greater appreciation for the immense work that goes into these games! 😍 I also have a massive soft spot for the legend himself, Mr. Dan Greenawalt. Thank you for this. 🙏

[@Falconite]

I'm a simple person, I see a new episode of War Stories - I give it a clicky clicky

[@rendyandrian7149]

With your background in martial art, it's so surprising Forza is a chill racing game. Compared to hot pursuit which focus on racing as well as vehicle fighting.

[@cabbagenjam]

Put hours a day into Forza 4 drifting and liveries, so much fun...

[@Inverted88]

This might be my favourite one of the series.

[@GeneralKenobi69420]

I absolutely did NOT expect that videogames could use neural networks so extensively... This is really cool

[@MrSkysommer]

LOVED this episode. Thanks for your work.

[@greenfefo_fpv465]

The explanation about the Laguna Seca corkscrew at 13:50 blew my mind!

[@sameertikoo7308]

My goodness. I loved how well he explained the challenges.

[@Ramaxx95]

So cool! Didn't know that the drivatar concept was used way before Forza 5.

[@PabloGaraguso]

The D&D Starter set on the shelf ... !

[@edh615]

This videos are fantastic, this video would've ended in 5 min but we get to dive a bit deeper, keep it up!!

[@ForzaCoPilot]

Oh hey, isa me at 10:48! This is dennnnsssee but so good!

[@seditt5146]

Great idea, I never knew NN was used in games yet and since you could use the players performance as the training model it means you have a game which would never get stale because the computer could learn as you learn and if you get worse the computer would get worse always keeping difficulty at a predefined level despite such a thing normally being relatively arbitrary.

[@MetalGamer666]

While I love the Forza Horizon games, I rank FH5 as one my best games of 2021, there is still a lot to be desired when it comes to the AI. Why do the AI just blindly follow the racing line in a train, never overtaking each other, never showing any individuality, if they are based on this amazing drivatar AI learning technology? The AI in FH5 is indistinguishable from a bunch of cars scripted to drive as a train on the racing line. Also, how can drivatars remind me of my friends when they are just randomly selected from my friends that doesn't own a single Forza game? At higher difficulty the AI takes turns at impossible speeds, and have very strong rubberbanding towards the end of a race. Both of these are extremely obvious, and there are endless videos on KZbin of this behaviour. So it feels like the neural network with the AI learning is offline, and the AI is just following basic scripts to follow the racing line and adjust their speed to the player.

[@CodingWithUnity]

he didnt actually say they drive like you, they just have less restrains on the 'AI' that is labelled as your friend. Its a feeling thing and not a "this ai with your friends name learned off your friends data", which it should be. I agree with all your points :)

[@varungupta2908]

This was amazing. More videos like these please!

[@Focus_883]

Great video, I loved how easily he explains a LOT of hard work put in it and how they handled it. Forza series is so much fun! never disappoints, last entry with dynamic seasons each week it is outstanding ✌

[@WynnofThule]

One flaw with this game's AI is that it shifts badly. For example on the 6.2 LS the AI shifts about 1000rpm earlier than it should. This AI also calculates the PI (performance index) of the cars, which means it underestimates the speed of the engines. This means that you can build a faster car at the same PI with an LS or another OP engine than with a bad engine, because of the AIs flaws.

[@alecjones4135]

I drive with my a wheel clutch and shifter so I also shift bad

[@beefchampion2792]

Great content guys! Always a pleasure to stop by your channel!

[@DJ_Asthma]

So so awesome, answered some questions I had for years on how the ai worked on unbeatable difficulty in the game.

[@Cyrribrae]

Man, this one was so cool!

[@andycrawley8276]

Dan, thank-you for passion ad knowledge . I love the Forza franchise.

[@Glados44]

What an interesting video. I love the fact that he explains How machines thinks when you race cause its the 80% of the game.

[@fhd21]

Just boaght FH4. My first Forza game. Great coincidence.

[@JeffSoulliere]

Have fun. FH4 is one of the best racing games ever made.

[@fhd21]

@@JeffSoulliere thanks Jeff. Already loving it!

[@AppleSlipper]

Dan used to work at Bizarre Creations on Project Gotham Racing, which was a reference in one of LaRacer's missions in Forza Horizon 4.

[@ozoak]

Absolutely fascinating, and in part that's thanks to the delivery by Dan Greenawalt, far more complex than I had imagined it to be. Started Horizon 4 not long after it launched, and after having watched this I have more questions! (Has the AI changed because of me, because of tweaks the dev team made in that time, how does me having only 1 xbox 'friend' play FH4 affect it, the list goes on.) The AI is definitely 'nicer' to race against now than near 2 years ago, that's for sure.

[@Intellllect]

0:45 ah, yes, I've heard that more than 90% of game developers started as martial arts instructors

[@CJW0056]

Well he's got something for his resume if he ever goes to Netherrealm studios, lol

[@88Elzee]

He said atypical not a typical..... Isn't English fun lol.

[@lolnahnvm208]

Please don't see the lower viewership of this episode as a reason to stop making these. They provide so much value outside of just fandom for a specific game.

[@Aman-ni4wl]

It was like dev story summary so nicely put

[@Tommy-T448]

I've been playing on Unbeatable difficulty for awhile now and I got 1st place 60% of the time. Here is a problem that I notice you didn't mention. The AI is really fast with all the improvement mentioned, but usually failed to account for the rise and drop of the road, which lead to loss of grip. Those places plus a curve can send the AI off track at full speed because they would have passed it if there wasn't a change of elevation. Also, you put faster AI in the front and slower ones in the rear, and the player at last place which make shorter tracks basically unwinnable. When you're busy passing the slower cars, that blocking you off of a good turn, the faster cars in the front already gained some distance. The longer the track, the more change you can win.

[@GraveUypo]

AI is only hard on tracks that have too few corners for you to compensate for their cheating and rubberbanding. the AI is awful pretty mediocre on the bendy stuff.

[@neetones]

This is a really fantastic presentation. Do more!

[@doodbob2250]

This was really fascinating! Ive always loved the Drivitar concept and this video gave a lot of 'ohh that makes sense!' moments. Recall a friend telling me he unfriended me on xbox because my drivitar would push him off the road. Learning that it was only friends who could make contact explains that!

[@RobinBSmith]

I'd like to petition for more on this topic and franchise

[@adamthompson6669]

I love how Forza and horizon are similar but vastly different. I love Forza and enjoy there games on a pad. Great video thank you so much. Feels good watching this knowing I got a series X order and ready for the next Forza can not wait 😁 ✅

[@FuchsiaShocked]

My friends keep telling me my drivatar is quite a challenge to beat, and the thing I'm always wondering is exactly how much credit can I take for that... like, how much like me does it actually drive? Because it's presumably going to be scaled according to the difficulty level my friends have set, and it'll be rubberbanding to make sure it's driving around about their pace...

[@satibel]

if yours is hard to beat but others are easier, you can take quite a bit of the credit.

[@Cyrribrae]

The speed of your drivatar is definitely tied to your driving. It's perhaps a caricature of your driving, but if you're faster than everyone else - that's probably because you're faster than everyone else lol

[@doubletee4391]

Thanks for giving us the forza series. I don't think i've ever gotten more enjoyment out of a series. If you could just get the wheel support dialed in a bit more on the newer titles things would just be perfect.

[@zbatchDOC]

This guy is insanely good in front of the camera. He could have been a tv personality.

[@phutureproof]

I do not mean this in an unfunny memey way, but I would love to see what cracked off at CDPR lately, surely they got some war stories to tell!

[@BlacklistBill]

If this series is still running, I have a request for war stories. "Way of the Warrior" on 3DO. Developed by Naughty Dog, ND was in bankruptcy at the same time they were developing the game, Naughty Dog employees were the actors in a studio that was an employee apartment, costumes involved happy meals.

[@happydad242]

Ok, when I get home I loading up Forza 7 again. This video made me appreciate the AI...

[@furiousbane]

Incredible video, some much detail!

[@darkdrengr5944]

Love these videos. As a gamer it's really cool seeing how the sausage is made, so to speak. Keep em coming!!

[@mhx47]

Very interesting stuff shared in this video. Just example of - players using analog joystick like it was digital. In GTA Online, I used keyboard. Then I decided I want to do races and drifting, so I grabbed Xbox controller. But I could not get the precision in turns as well as on keyboard. But why, it was supreme analog. Turns out, serious race drivers in game use analog stick like it was digital - nothing or full tilt. That did not seem right to me, so I abbandoned it and went back to keyboard. In forza on Xbox 360 analog use felt right to me, no need to go full tilt or nothing.

[@FrankHerfert]

amazing walkthrough, thank you

[@MasTommy21]

Thank you for the great video. I don't comment a lot, but this is really valuable information

[@Route765]

I’d like to see the new AI in the new Forza Motorsport. Unbeatable in FM7 isn’t fast enough

[@housecaldwell]

As a software tester myself, I'm both fascinated and terrified by how neural nets are being used so much today. How do you test it? Think of the problems this team ran into when some value was generated that caused an AI car to deliberately hit another car. Now think if that AI was in a real-life Tesla semi. :-) How do you test so that those freak values are never executed in the real world? I don't think anyone has the answer to that yet. Do we need to train neural nets to test other neural nets?

[@skorpius2029]

Would be cool if they could make AI drift realistically and make special events for that.

[@troyjarm7901]

But I love how they look like a cartoon weird slide, it's funny because you know it's nowhere near realistic haha

[@theFloxie]

8:15 yes you hitrestart when you go off because your race is over, it's done.

[@Michaelandthisisit]

exactly, what is he on about?

[@KvVortex]

This music is giving me MAJOR marble mountain vibes...

[@dustintravis8791]

Really cool insight, thank you.

[@ashblack6292]

I’m really happy I’ve seen this video as I always thought Drivatar was a complete lie. Me and my friends drift every corner because the “unbeatable” drivertar is just so damn slow. Yet our drivertars don’t drift at all. I now understand why I also now understand why they’re so slow I’m also really excited to see someone at Turn 10 acknowledge that they’re sooooooo slow and they are working on it. It kinda sucked to think “this is it? This is what they’re giving us?” But no, they are working on it I’m an even bigger fan of the Forza series after this. Top stuff!

[@Jourmand1r]

it is a lie. this man lies to your face with a nu-male soy smile the entire video

[@cbz3237]

Fantastic video!

[@JerryKosloski]

And they'll still crash into you like you aren't even there.

[@Mkoivuka]

TL;DR: "Pertinent digitalization of processes requires an incredible amount of resources. Perhaps the most efficient organizational structure to realize these sorts of developments is as a videogame company, as the developers' passion for pertinence coincides with their own background and interests."

[@Brentt777]

NASCAR Heat needs to see this. Their cars have zero physics

[@TheAxlSnaks]

Forza's NASCAR add-on is amazing

[@grantlauzon5237]

AI won’t improve the physics just the way the opponent cars drive. Heat is made by a small team with a small budget and I don’t think they could improve to this level. They also need to have 40 cars running so AI and physics need to be simplified in order to keep frame-rate up. If they could work with Turn10 they could make vast improvements but the cost of doing that could be large.

[@grantlauzon5237]

axlsnaxle I think a NASCAR game built on the FORZA engine would be superior.

[@117johnpar]

unexpected super informative tedtalk

[@nfsjoey]

As someone who spend way too many hours in Horizon 4 and I can tell you now the AI have the equivalent IQ of a newborn

[@alecjones4135]

Unbeatable AI?

[@nik021298]

@@alecjones4135 Not him, but I'd say yes. They crash too much and make many mistakes, if you leave the track the rubber banding is noticeable. Which is annoying.

[@KennTollens]

I have a computer science degree, always wanted to test games, but never gets hired for it. Some other guy, yeah, I don't didn't really know anything about computer and doing totally unrelated stuff and just stumbled into it. I see this a lot in the computer industry. Asked senior developer, how did you get into your position. Well, I majored in music, but needed something that paid more and made a phone call, I didn't even know how to program when I got hired.

[@cainacosta2853]

8-bit guy looking jacked!