"Humans are by far the hardest part of computer graphics because millions of years of evolution have given us dedicated brain systems to detect patterns and faces and infer emotions and intent because ..."

"The following is a conversation with Tim Sweeney, a legendary video game programmer, founder, and CEO of Epic Games that created many incredible games and technologies, including the Unreal Engine and..."

"What was the value of the hours as a kid you put in in programming that led to the success you've had in later life? Maybe this is by way of advice to younger people in terms of how they allocate the ..."

"That's right. and constantly striving to make connections between these fields and look for their applications. Long after I chipped on Unreal Engine, it was like going back through an engineering tex..."

"And you know, people often go to university and think, okay, my goal here is to get good grades, so I get a diploma and I prove to an employer that I'm valuable. like no that's just kind of the superf..."

"So on the video game side when did you first fall in love with video games? I've had a funny relationship with games because my real aspiration has always been to program cool stuff. I get more enjoym..."

"90s. So you launched Epic Games in 1991. So your the writing of your first big video game uh ZZT. What was it like? What was the technical challenges? What was the psychological challenges of building..."

"didn't just build this one game. I built a a trilogy of three games. Um, Mhm. I released the first one for free. And I said, hey, if you like this, buy the two sequels. Um, and I included my parents m..."

"story though. You start out building a text editor. So you're looking at this project, you're playing around with it you're building up the tools. It's it's such an inspiring moment cuz uh a lot of us..."

"to make awesome entertainment but also awesome tools and to share those tools with everybody so they can build their own amazing things too. And um you know when we got into Unreal Engine a few years ..."

"benefits. If we could just linger on the '9s. Uh, so you said bulletin boards. Maybe you can explain what that's like and also explain the birth of the internet, what that was like. What was the what ..."

"its own. It became much much easier to reach a global audience faster and you would start shipping games to the internet which is a bit of a crazy thing to do cuz you're supposed to have like a you kn..."

"you tried to satisfy a small audience rather than competing globally with the game juggernauts. You know, back in the 1990s, Epic was new, but Electronic Arts and Activision and the other big publishe..."

"become platforms for other people to build stuff was a real opportunity. You know, I think the big thing to realize is for indie developers right now is like there's massive massive competition in eve..."

"of that. You said that uh when Wolfenstein and uh Doom came out, that changed everything. So, take me to that moment. Yeah, that that was a very interesting time. Epic had uh after my first couple of ..."

"had a little office and we were you know copying floppy floppy discs and mailing them out. But um when Wolfenstein came out, we realized like the future of gaming is going to be 3D. Um it there had be..."

"um and and real um yeah You might you might look at it today from a you know point of view of a a modern uh you know game player with uh you know 20 teraflops of computing power in your device and say..."

"I was really depressed. I I fig cuz the wizardry of Doom especially was so incredible that I gave up on programming for like 6 months. I was like I never be able to compete with this. I have no idea w..."

"so we took the best people from our best 2D game development teams and put them all together to make a 3D game. Um we didn't really know what we were doing at the time. None of us had ever shipped a 3..."

"survived and almost ran out of money a number of times, but uh somehow we always pulled through and um it was a crazy project because it was three and a half years of development in a game that we alw..."

"figured out how to do volumetric fog. So you could have foggy areas that were full of lights and you get the kind of glow of the lights standing out in the fog and affecting the appearance of the leve..."

"actually deliver the game? Yeah, that that's one of the really unique things to exist in gaming. Not in normal big tech companies which are just engineering and businessdriven, but gaming really does ..."

"dedication to it that made it work. I heard you still program, but uh how much programming were you doing back then? You mentioned the hours, probably insane hours. So like uh it'd be almost fun to ta..."

"them and looking at what's going on in screen and figuring out what they needed 5 hours of business stuff. Um and you know there's a good division at labor of labor then. Um, Epic didn't have a big ex..."

"of all those languages ended up being the the dominant sort of performanceoriented language that survives to this day. Yeah. Yeah. It's because it solves all the problems uh at scale. Um often through..."

"the main consumer computers at the time. And I'd optimized the Unreal Engine software render on that which was you know the Pennium was the first super scale scaler architecture in consumer computing...."

"so we did most Unreal Engine development before the first real GPUs came out. Um and, uh, you know, the the 3D effects Voodoo one, the first GPU that actually delivered serious performance compared to..."

"when we talk about optimization in software now it's largely about heristics and statistically you're you know this memory access is likely to hit the cache um and you know this algorithm is faster th..."

"Nani is the system we'll jump around in time. That takes us to today with Unreal Engine 5. That's the system that does the geometry. Yeah. So rendering the world sort of geometrically. There's many la..."

"any more than necessary. And you know, with geometry the idea is that if you if you render two triangles per pixel, you should get an image that is indistinguishable from thousands of triangles per pi..."

"a lot easier to render one frame that looks perfect than it is to render a you know, a series of frames in motion that look perfect. A lot of the problems with the earlier algorithms uh that aspired t..."

"reality in real time like lights changing everything and then you know it just takes you back to that feeling I had with Wolfenstein but like more and you can completely lose yourself in that world an..."

"bundle of code and tools, a huge software package um that provides all the functions you need to build any sort of a 3D graphics application um game developers use it to make games and that's the pred..."

"huge variety of styles from Pixar stylized movies to cell shading um to photo realism. Um and it can be used for anything that needs a needs real-time 3D graphics including humans that populate those ..."

"geometry output and you know just plowing through it uh eventually uh through mostly deduction but some trial and error too like sometimes you just have to try the possibilities and see what works. Um..."

"What about like lighting? Is there other interesting Well, the funny answer is like we know the laws of physics. So it's actually really easy to do everything in computer graphics, but uh the direct s..."

"Carmarmac had figured out uh how to do uh really cool lighting algorithms including real-time lighting with objects moving around. Um and uh I hadn't taken it very far. So with Unreal Engine, I' I'd r..."

"bunch of elaborate lighting effects, um like torch flickering, um, and you know the costic effects of water bouncing off of a surface, uh, and so on. Um, so and pulsing lights and blinking lights and ..."

"thing. I was just like typing in these little features, uh, exposing them to artists. And every day they'd find like a drop down with some more lighting options available to them, and they'd start usi..."

"seeing a revolution. This is blowing my mind. This is so fun. What about fog? You mentioned fog. That I don't even know. How do you even do fog? So, you mentioned Unreal. So, the first version had fog..."

"time volumetric fog. I have to figure it out myself." And so that was another like 30-hour coding session. Um nice. But but like at the core I realized okay what's happening here is we have this light..."

"you this transformed 1 / r^ 2 is turns out to be solved by the arc tangent of r. Uh and so you know if you calculate the some parameters based on the position of the eye and the position of the surfac..."

"That is so awesome. That is so inspiring on so many levels. Yeah. That you saw that maybe it's possible even if it was kind of smoke and mirrors u and then you actually made it happen. It's so it's so..."

"problem. And you know I think that that stands as a lesson for every programmer to pick up on when something is really really important um its performance is absolutely critical to the product or its ..."

"the hardware uh is improved incredibly but uh in order to create an ultra realistic uh highly dynamic realtime rendering of the world around us, it's still really really difficult. And there's all the..."

"Like you know if if we had that in aviation then we'd be like taking a trip to neighboring stars off of Centauri. Yeah. Exactly. Um and uh in in graphics it's been been even more so. It's something li..."

"You know, Unreal Engine 1 was built for software rendering and then the Voodoo one came along late in the cycle and we added support for it but wasn't fully fully capable and utilized. Um, Unreal Engi..."

"um you know which which I think really bridged the gap gap from you know game game gameish computer graphics to you know total observable photo realism um for artists who wanted to create that um and ..."

"want to burden either ourselves or our partners or the community with the complications of multi-threading. Um and you know over time that becomes increasing limitation you know so we're really thinki..."

"artists and technical artists who worked together to build this environment because it and the reason we showed it at GDC was it went way way beyond what we uh realized the system was capable of doing..."

"interplaying between the you know the ice and the dirt there, uh that's screen space lighting. Uh there's actually shadow calculation going on uh not based on the world but on the pixels on the screen..."

"the shadowing influences other things. There's also, you know, some really interesting things happening with the color here. And I'm not even sure what's causing, you know, it looks like color is blee..."

"make a number of technical art decisions to make this work. And if a novice who hadn't, you know, worked very hard built the kind of scene like this, it wouldn't look nearly as good. So, one of the ch..."

"talk about in the presentation is about snow. So, you have to if you're talking about 1943 in Nazi Germany in the winter, you know, uh there's a you have to create a feeling, one of which is the seaso..."

"that. And that's on top of the sort of the geometry that create that creates the the structure of the scene and all the occlusions that have to be computed. I mean okay I got to go to the other one th..."

"artist sophistication. Um it's a very very very large part of it. So yeah again it's the interplay between the tooling and the and and the artists. But yeah, like that I could I could watch that for a..."

"humans? So, you have an actor behind this to convey emotion, show the nuances and the details of the faces. And maybe this is a good opportunity to also mention metahuman creator that's part of Unreal..."

"real-time replicatable version of that human in in the environment. And so one of the things that's done is just capturing an actor or actress in the real world and then using them in a video game. Bu..."

"representation of that. So that's the data problem. There's a lot of other problems of computer graphics. You know there's technology for rendering hair which is really hard because you can't render e..."

"beginning of a formation of a smile that actually reveals a deep sadness. All of that like when I watch a human face, I can like read that. I could see that. Again, this is the the engineering and the..."

"that made the magic of it happen? Lumen is a system for global illumination meaning it's supposed to calculate the interaction of light uh with the entire scene in a in a way that mimics reality. Um t..."

"much easier. Yeah. I mean, we're watching so I recommend people go through this blog post like look at that. So dynamically, I mean, we should say that. So there's the indoors and the outdoors. And to..."

"And then to put the power of the tooling in the hands of an artist, that is really special. Yeah. The industry's gone through a massive evolution and just so many supporting systems to make this aweso..."

"to me as a fan of well let's say beauty in the world. It's it's exciting that we can create that synthetically artificially um via graphics. And that just it blows wide open the possibilities of story..."

"It's as much because the actors are able to do their jobs better seeing the scene they're in because the technology is enabling a better lighting calculation um and a better interplay of virtual light..."

"learn new ways of doing things. Um, and it's always been this way. And I think that there's also a lot of overhype in AI. AI is really great at spewing out code that does something that a million GitH..."

"or real. Um, and yeah, I think that's going to be the the primary challenge of graphics development and simulation development over the coming decade. So the realistic humans, that's going to be the b..."

"we're in it? Well, I don't think that these questions are necessarily unanswerable. I think I'd like to see more actual effort to to ascertain like what is the underlying mechanism of the universe and..."

"entertainment like the many other things that people do uh do for fun. So, uh you've spoken like I mentioned about the metaverse for many years. Let's step back. What is the metaverse? And speaking of..."

"gaming industry was Fortnite. Fortnite Battle Royale especially. Can you explain the origin story of Fortnite? Well, Fortnite has humble beginnings. Um, in 2011, we just uh uh been in the final days o..."

"same exact time? Like what's the technical four weeks? What's the technical challenges there that had to be overcome? Since 2012, we'd been building online backend systems to support player accounts a..."

"without buying any server hardware. We were able to just call up Amazon and say we need more. Um, and there was a period of time there where Fortnite was undergoing this exponential growth and we'd fi..."

"investing in that. Yeah, it's exciting to see that you investing in a long-term future. Sort of taking the risk of doing the research and defining the next chapter of Epic. So using the successes of t..."

"kind of thing. Let me start with the present of gaming and why it sucks. Like that's a good start. Sure, Fortnite is an awesome thing. You go into Fortnite there's, you know, 100 million monthly activ..."

"and their stuff. So, the solution to this is to federate and connect all of the systems together. All the players on all the different platforms can be recognized by their name um and put the at sign ..."

"are two big things happening um in Fortnite that make it work as a product and as a business. One is the game modes, Fortnite Battle Royale and all the user modes and everything else are sources of en..."

"as well. That would be incredible. That would be so amazing. Is there first of all just it seems silly maybe for people who don't play video games but an outfit is an important if if an outfit can be ..."

"games uh, have that characteristic. One one funny anomaly stood out. There's this game that was one of the big breakthroughs in Fortnite, Only Up. It's a game where you're just climbing up and up by f..."

"way to do that and to to basically create standards the way the web has different standards for for displaying websites and all this kind of stuff or the the the communication that's required on the n..."

"is a programming language that's uh at the center of standardizing the metaverse. Now um if you look at the web, the web is a combination of a bunch of different technologies. The two biggest ones are..."

"collaborative uh first of all also the the amount of data I mean it doesn't have to be that way but websites are showing very little information uh the metaverse even when it looks like something like..."

"performance. It was just not possible to run it. So, you got a certain level of technical capabilities and a genre came out that proved to be by far the best shooter genre ever invented. But I think t..."

"separate companies or their own you know entrepreneurs or uh indies or enthusiasts all working together simultaneously and we totally lack the programming foundations for that uh you know the the kind..."

"maybe you could speak to this programming language called verse. It's a functional logic language. What is it? What are some cool features of verse? First is a programming language that we're building..."

"adopts it in a way that's really userfriendly so you don't have to do that. Um and the idea of this is that you want gradually more information to be incorporated in the types of variables. The proper..."

"where like at compile time you could prove that the program is correct in some sense of correctness? Proving things becomes commentatorally harder as they get larger, right? And so the really importan..."

"function that sorts these this array and prove that it did that. Um, it could actually write the proof and uh you could if the compiler didn't beep with it, you could trust that it was actually sortin..."

"type system. And you know, one of the important thing for programming languages that hasn't been given enough attention is some aspects of programming languages are just subjective. They're just machi..."

"feature of the language supports program are abstraction over that feature timeless built for the needs of today and for foreseeable future needs. Yeah. And and then there's some design goals that we ..."

"hard. Uh it's so hard that we've in five generations of Unreal Engine, every single generation decided we're not going to try to scale up all of our gameplay code to multiple threads um manually. It's..."

"then you might have somebody read a bank balance, subtract 100, and write it out. But in the meantime, somebody has written something else in the meantime. And so you might get inconsistent bank balan..."

"people have to actually make this work. That's amazing. That's really incredible. Um, so what's the state of things with verse? And I guess what you're outlining is if and hopefully it is successful, ..."

"developer to build a a game of any sort. Um either or simultaneously both ship it into Fortnite as a Fortnite island that players can go into bring their Fortnite items and cosmetics and uh interopera..."

"much genius and artistry out there that we want to support the crazy dreamers out there. Anyway, all that to say, what are the ways you think Epic can support indie developers like that? People like G..."

"really valuable thing. In the early days, pretty much one person would build one game. Like that's how a lot of the games were built in the 1980s. Um over time, you had a separation where artists beca..."

"sell it, they could build a business around it. and they were completely uh able to without seeking any big tech corporations permission uh do whatever they want even from IBM remember IBM was the dom..."

"popped up and they don't provide any useful value uh to the user. Yes they're a search function to find software, but there's no reason other companies couldn't build a better one. And I bet if you ha..."

"when a user searches for like when a when before Apple blocked Fortnite on iOS, when a user searched for Fortnite the first result was always some competing game. Like that's utterly anti-user. Like y..."

"step up? All companies are terrified of Apple um because Apple can destroy their business. Um Epic was in a unique position with Fortnite. First of all, having the, you know, the biggest game in the w..."

"And Apple has a very long history of playing cat-and- mouse games with developers. It's like a developer uh isn't in Apple's good graces. They'll just slow down the updates. They'll they've been slowi..."

"Apple can build certain kinds of apps or only Apple can integrate certain features. Um, in Europe, even where the DMA law requires Apple to allow competing stores, they say a store can only be a store..."

"monopoly that's forced to compete suddenly the monopoly's products get much better. The offerings to consumers get much better. You see so many areas where Apple could be the best. uh but what they ha..."

"one is just on the wrong side of history and needs to change. Well, I hope Epic and Apple find a path forward together and flourishing together and Apple embraces competition better. One of the things..."

"Like there's just not enough celebrating of awesome shit that let's If I can ask the internet as a blob one request, can we just celebrate awesome shit? and also criticized, but just like there's not ..."

"times and we've gone through multiple refactorings, but you know that that's definitely been a disappointment to us and to a lot of users. Um, and I think one thing we had to it took us a while to rea..."

"Store uh, supports an immense amount of Epic Games commerce in Fortnite, on PC, um now on Android and iOS and the European Union, too. Um, so it's a forever facet of the industry, and we are never los..."

"world of gaming today. And it says that you know, your game is quadratically more valuable the more percentage of a user's real world friends they can connect to. um your game vastly benefits by conne..."

"understandable that it's needed for the competition for the underdog to to to enter the scene, but it goes against the sort of the freedom, the the free spirit of choice that I think you represent a l..."

"know, what can possibly be done to get a dominant store with you know something like 90% of revenue share from you know among you multi- publisher stores uh you know in line to so that a much much sma..."

"Thanks. One more bit on that exclusivity point is that when we we told Google that we were going to launch Fortnite outside of Google Play and go into competition with them, they viewed exclusivity as..."

"can do that. Look at competitive businesses. They have a margin of a few percentage there. The numbers there are strikingly uh supportive of just outright anti-competitive market distortions. Okay. Wh..."

"most part. And there are exceptions to that. Um, but I think we're seeing much much more play time shifting towards games you're playing together with your friends and not just random internet strange..."

"Roblox is bigger than ever. And you know this trend is players consolidating into multiplayer experiences they play together. And we're seeing another trend overlaid with that which is like when an aw..."

"rather bleak outlook for a lot of the category of like single player games that don't have a huge audience to reach. Um, and you know, but this is just one of the really trends of restructuring the bu..."

"Just the attention to detail and there's something there that's big and it's been funny journeying through the industry like I I last designed a game in 1992. I'm not a game designer. Um, yeah, I have..."

"interact with each other online. That's a really fascinating thing. I wish would be studied more. I think we talked about the soul on several fronts, right? I wish it would be studied more. Yeah. Yeah..."

"that's its own thing, right? That's uh that world, the characters, the style the edgginess, all of that. But the the interesting thing about Grand Theft Auto 6 to me that I want to ask you about is th..."

"feel like Rockstar is a good example of that? The pressure of delivering quality. You you know Epic has not missed recently that I'm aware of in terms of delivering quality. You feel the pressure of t..."

"because of just the social dynamic that those platforms have have brought on. But then I compare that with the good spiritedness of uh of what's happening online when you're connected to real people l..."

"better and I am grateful that you are pushing the boundaries of what's possible in creating such worlds and I'm grateful that you would talk with me today Tim this is amazing and it's an honor uh to t..."