YouSaid · the spoken record

Tim Sweeney

lines on the record: 296
first: 2025-04-30
most recent: 2025-04-30
sittings or episodes: 1
sources: podcast

Every line below is reproduced as it was said and linked to the record it came from. Nothing here is summarised or generated. Directory · Search · Corrections

“Real time. And then decades later, I was talking to one of the engineers who'd worked on that hardware and asked about their valiometric fog and told them how it inspired me to figure out how to do it in real time myself. I was like, oh no, we cheated. We just rendered it LA 3D Studio Mex.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“And yeah, thankfully, people have solved them all, and you realize the integral of this transformed 1 over r squared turns out to be solved by the arctangent of r. And so, you know, if you calculate some parameters based on the position of the i and the position of the surface point you're ultimately seeing, then you calculate exactly how much fog you can accumulate from that. Of course, you can't do that per pixel because that's hundreds of cycles of CPU time. And so what we had to do is calculate volumetric fog on something equivalent to a light map, but calculating fog every square meter in the world. And so we had enough performance for that, built value metric lighting and gave it to the artists, and they started building magically detailed levels with value metric fog.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“But at the core, I realized okay, what's happening here is we have this lighting function saying the light at a particular point in space is like, you know, falling off with the inverse square of the light, the distance from the light source, right? The inverse square is off from Isaac Newton, which applies to lighting. I had to realize was that the way the fog interacted with the light was that you calculate the view from your eye's position to a point on a surface in the world. It's going through fog and you're accumulating more and more light as a function of the amount of light illuminating the fog at that point in time. And so, well, you know, I'd studied that in mechanical engineering without even knowing it. That's the line integral. You have an integral over a line of some function. Well, this is exactly what it's for. It's for accumulating the values of a function over a continuous space and time. And I did a bunch of math and realized that, oh wow, the integral, and I looked in a reference book of all of the integrals.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Yeah, well, it's a funny thing. So this graphics hardware company had just started up in Finland, and they released a screenshot of what their GPU was doing, and they showed a scene filled with volumetric fog. See how a foggy room with some light sources in it? And when that happens in the real world, what you see are glows around the lights as the light brightens the fog around it, but the brightening of the fog diminishes over time because the fog absorbs some lighting. And so the further you get away from the light, the more the more falloff there is. And you have a bunch of colored lights overlapping together in a space like that. The effect is just absolutely magical. Like being out on a foggy light with street lamps above, it's something that's surreal and just beautiful. So it's like, oh my God, they figured out how to do real-time valiometric fog. I have to figure it out myself.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Right, it's timeless. What do the Renaissance painters do with paints? And what do the early game artists do with early engines? Everybody's figuring out the capabilities of their medium. And you're seeing a revolution.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“So I was running around at half a frame a second, like shooting out light projectiles and looking at dynamic lighting. It was like, someday computers will be fast enough for this, but not today. So I made a non real time version of the pre-calculate, saw the lighting, and realized, oh, wait, if you precalculated the shadowing in an object, you can still apply the lighting dynamically as long as the light's not moving. So you could do torch flickering with shadows. And I figured out all the cases of dynamic and static lighting that were actually practical on a computer at the time and expose them to artists. And this was the wondersful thing. I was just typing in these little features, 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 using them. And they'd do things that I never thought possible. And this was always the coolest thing. As a programmer building an engine, you might think you know the implications of the feature you're building, but artists are so clever that you always find that you've built the capability of doing vastly more than you ever anticipated as they start to use combinations of features together in concert to do ever more amazing things.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Then I implemented shadowing algorithm. If you cast array from a point from a light to a point on a surface and see if it intersects in the other geometry, if it doesn't intersect and the light hits the object, and if it does intersect and the light hits something else first, and that pixel on the object should be dark. So I built a real-time version of this and it ran at about half a frame a second.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“And we're doing it on light maps. We can actually do some pretty expensive calculations, hundreds of cycles since we're only calculating it for every one foot of world space rather than every pixel. And so we introduced a whole bunch of elaborate lighting effects, like torch flickering and the caustic effects of water bouncing off of a surface and so on, and pulsing lights and blinking lights and everything else and created a system, I created a system for compositing them together. So if you had an arbitrary number of light sources, they could all do that.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Computing performance and our CPU to compute the light of every pixel on the screen from all of the light sources that affect it. We were at a six-cycle texture mapper and we couldn't afford 30 more cycles for lighting. And so the answer had to be some approximation. And the one that Carmac had picked up on in the Quake engine was light mapping. If we, instead of calculating all the lighting on every pixel, if we made a big texture that we placed over all of the walls in the scene that was like wallpaper, and what if we say every foot we're going to compute a lighting value for just that one foot grid on the object rather than computing it everywhere? And then if we, well, if we just linear interpolate that over the course of it, you get a lighting solution that actually works pretty well and is fast enough to work. And so a lot of Unreal Engine's lighting techniques were based on Light mapping. We introduced colored lighting. So you could have colored light sources. Then we realized, oh, since we're doing this,”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Yeah, photon tracing is the subject matter that does brute force calculation of pixels on a screen from all of the light in the scene. Work since it's cracked, and it just is an implementation of laws of physics, and millions or billions of times slower than what we do. But Carmac had figured out how to do really cool lighting algorithms, including real-time lighting with objects moving around. And I hadn't taken it very far. With Unreal Engine, I'd realize we don't have nearly enough.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Well, the funny answer is we know the laws of physics. So it's actually really easy to do everything in computer graphics, but the direct solution... The laws of physics is immensely slow. And so what we're finding are approximations rather than complete solutions. Because you need something that's a million times faster than the brute force answer.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Yeah, you know, it's pretty easy to write software that's like 99% correct. It's the 1% that's the really hard part where the devil lies in the details.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“What cases should you keep them? What cases should you eliminate them and so on and so on to create really efficient geometry output? And just plowing through it eventually through mostly deduction, but some trial and error to, like sometimes you just have to try the possibilities and see what works. Yeah, I cranked it out and it worked. And the next day I came in kind of weary and I was like, oh, wow. This actually did work. It wasn't just a dream.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“So the foundation for the subject is the binary space partitioning tree. This data structure invaded by a computer science graphics researcher, Bruce Naylor, Carmac had picked up on that and had used the technique in Doom to really great effect. And I'd picked up on that. And Underwinchin was using this technique for all of its graphics and rendering, but it was just additive geometry everywhere. And it had a lot of overlapping polygons and was pretty inefficient. So I had the idea that if we had a BSP tree, there was a really efficient way to do constructive solid geometry. And to do that, you had to break down the ways that different pieces of geometry can fit together. I broke it down into like 14 different cases. And most of them are pretty simple. Crank them out. Anyways, I got towards the end. There were some pretty complicated things like, how do you deal with coplanar polygons? They're in the same plane and pointing in the same direction versus the other direction.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Because there are symptoms that are well studied of sleep deprivation. One of them is short-term memory loss. And so you're working without the easy recall of the code you just typed. But your brain is then freed to think about other problems. And I'd build up this intuition over a very”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Your brain works in different ways. Depending on your state, right? Some things that require really working on a problem fresh where you've put together a bunch of logical pieces and now you need to write a whole lot of code to make it all work together and plumb a whole lot of data between a whole lot of different algorithms. But I think our brains have vastly more horsepower than we're able to directly access by thinking of what code to type next. After you've been working for a very long time, you can get into a sleep deprived state where you have much, much more direct access to that low level knowledge.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Cylinder from it and created this really advanced composite object with just three operations. He was like, whoa, I can't believe this. It's like, yeah, we figured it out. And that was cool to see for the first time. It was probably the first time somebody had done constructive solid geometry in real time. But it was also a really useful tool that all the artists appreciated immediately began making use of.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Voting is extremely tedious if you are only adding objects to the world. If you want to build a door, then you need to add like a dozen different pieces of door frames and add a bunch of different walls together to fit together in the right shape. It sure would be easier if you could just start with a wall and subtract the door out. And so we had this way of adding geometry to the world and subtracting geometry. And the engine would perform all the calculations on that. And this is something that I'd been anticipating was possible for a long time, but when I finally got around to it, it took this 30-hour coding session to figure out all the special cases of the code that needed to be implemented to make that work. But in the course of 30 hours, I got constructive solid geometry up and running. I started doing, like, handed it to James Schwartz the next time we were together. And it's like, okay, I think you're cheating here. So you create a giant torus and then add another giant torus interlocked with it and then subtracted a”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“A lot. Some of them are visible on screen and some are behind the scenes still require a lot of innovation. All the graphical techniques were really interesting challenges. And on Real Engine, in those early days, went a lot further than the Quake engine and building environments using constructive solid geometry with a real-time editor. And that was a really interesting technical challenge. The idea is...”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“But this was one of the critical things that kept Epic going through that three and a half years. We're starting to license our engine out to other developers. Microprose took two licenses and we got in half a million dollars from that. And company GT Interactive licensed our engine to build another game. And we got paid for that. And so we had this revenue stream funding the development of Unreal Engine from other games that were being built by other developers. Because they were the lifeline for the company, we took the engine business very seriously from the start. We set up mailing lists so that our partners could ask us questions and all the developers and artists working on our games were participating in helping customers. Everybody took that very seriously because it was our funding source. And that's kind of set this dual spirit of epic of boning technology and supporting game developers simultaneously with boating games and supporting gamers.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“And as we began marketing the game, thinking it was six months away, we were constantly releasing screenshots and things like that. Other companies started calling us and saying they wanted to build 3D games too, but they didn't have the expertise for that. And they wanted to license our 3D engine. And this was one of the coolest pivots in Epic's history. Microprose called up Mark Rain, Vice President and longtime business guy. And so they wanted to license our engine. Mark Rain was like, oh, what? You want to license what? An engine? What engine? And they explained to him what they wanted to license. He said, oh, that engine. Yeah, yeah. That's very expensive.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Yeah, well, you know, the philosophy began with ZZT and continued onward. We're not just building a game for players to play. We're also building tools that could be used for building that game or any other game and catering to all of the artists and designers who had used the tool. And so that philosophy started at the very early parts of Unreal development. I was building the tools for level designers like Cliff Pacinsky and artists like James Schmontz.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“From Pixar stylized movies to Sojating to photorealism. And it can be used for anything that needs real-time 3D graphics.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Yeah, Underwin is a big bundle of code and tools, a huge software package that provides all the functions you need to build any sort of a 3D graphics application. Game developers use it to make games, and that's the predominant use, but it's also used in Hollywood film and television production to create 3D scenery in real time for production sets, to do pre-visualization. It's used by car makers to visualize their cars before they're constructed or manufactured. It's used by architects to preview buildings before they're made and industrial designers of all sorts. And it provides all of the 3D simulation features you need, both for creating highly realistic 3D graphics, but also physics and interactions between objects and making things happen like you might see in the real world and supports a huge variety of styles.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Yeah, yeah, that's right. But there's a lot of challenges like that. It turns out it's a lot easier to render one frame that looks perfect than it is to render a series of frames in motion that look perfect. A lot of the problems with the earlier algorithms that aspired to do this sort of things was popping. You'd be running some number of triangles for a while and then you'd switch to a different number of triangles and you'd see a visible transition. And screen would look like it got shaken up. It's a disturbing artifact. It distracts you from the game. So one of the magical trade-offs of nanite was how to avoid all the visible transitions and get them down to a point where Statistically, they're not really perceptible water person looking at it.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Thousands of triangles per pixel. If you render less than two triangles per pixel, you're going to start to see visible artifacts of the loss. And GPUs have this amazing hardware in a lot of different pipelines, but it's all very fixed function. There's pixel shader hardware, there's geometry processing hardware, and then there's triangle rasterization hardware. One of the limits of GPUs is that the triangle rasterizers are built for pretty large triangles. If you're building a triangle or rendering a triangle with 10 pixels, that's pretty efficient. But if you're rendering a triangle with one pixel, it's very inefficient. So one of the breakthroughs Brian made was to design an entire pipeline for avoiding the rasterization hardware in the GPU and just going straight to pixels and calculating what should be done with that pixel as a result of some ray tracing and geometry intersection calculations done in a pixel shader. So instead of using the triangle pipeline, we're just using pixel pipeline.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“In the texture that you have on the screen. And that's called the Nyquist limit. And so one of the challenges of computer graphics is given the need to render objects at extreme close-up distances and extreme faraway distances. You always want to be able to generate the right amount of geometry so that you have enough to be indistinguishable from reality, but not any more than necessary. With geometry, the idea is that if you render two triangles per pixel, you should get an image that is indistinguishable from”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Yeah, you know, with the advanced art tools we have today, it's really easy to create a scene with billions of polygons. The hard part is how to render it efficiently because you can't render billions of polygons in a frame. Basically, you want to render an image that's indistinguishable from the full detailed geometry if you rendered it at ridiculous cost. And so the challenge is how to simplify every component of the rendering, the geometry, the lighting, and so on down to real-time techniques. They're efficient. They capture a realistic view of what's around you. And so when an object is up close to you, you want to render it with a lot more polygons than when it's far away. But one of the cool principles of mathematics is the Nyquist sampling theorem that says if you're trying to reconstruct a signal, there's a limit to the amount of data you need to bother capturing. If you want to render a texture at a certain resolution, then you never need more than twice the pixels.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Yeah, that's absolutely so. The optimization problems have just moved around. In a system like Nanite, the virtualized micropolygon geometry system that Brian Karras, a brilliant engineer with Epic, built was just one of those multi-year optimization efforts that required him understanding everything from the highest levels to the lowest levels of the hardware to figure out how to make this breakthrough technique work in a way that was actually maximally performant on GPUs”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Now it's largely about heuristics and statistically this memory access is likely to hit the cache. And this algorithm is faster than that algorithm because CPUs now have such advanced out-of-order execution that you really can't micromanage what's happening on an instruction by instruction basis. You can only manage the aggregate performance of code. And so there is kind of this lost art. Some people miss it, some people don't, in which the programmer had absolute control over the machine and could work miracles in special cases if he tried.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“And you know, so we were talking about how many CPU cycles. You know, when you say your CPU runs at a gigahertz or whatever, billion instructions per second. How many instructions do you need to run to get APEX on screen? And so there's a constant challenge to optimize that down. And there was also competition among all of the graphics programmers who would often send emails bragging to each other about what new technique they've discovered to try to get the cost down. Abrash's original articles took like 12 CPU cycles to render a pixel. And everybody else had figured out how to get to like down to six or sometimes even four cycles. And that involved lots of different trade-offs of caching and memory hierarchy and so on. It was just like a magical time where a human could actually understand exactly what the CPU was doing under the hood and could write code that exactly targeted that. And that's largely lost now. When we talk about autonomization and software,”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Well, at the time, so we did most unreal engine development before the first real GPUs came out. And the 3D effects Voodoo won. The first GPU that actually delivered serious performance compared to software rendering. The first GPU that was really gainful came out in the end of the development, and we supported really quickly, but it was not the target all along. And so development was focused on just building, there are two parts of the engine, right? There's all of the gameplay systems that manage the simulation and physics and so on. That's all written in very high-level C++ code. And maintainability is as much of a goal as performance, because we had to build massive amounts of systems over time. But one thing that was really a bottlenecks graphics, you know, the cost of rendering a single pixel was really high. And so you had to do everything you possibly could to optimize the rendering of pixels on screen.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Configuration that money can buy. It costs $7,000. I had a gigabyte of memory in 1996. A 200 megahertz CPU. So it like tripled the speed of compiles and just made me massively more productive. So that's why I was using throughout Unreal Engine development and shipped with that.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“In 1996, that was pretty cool. So I'd upgraded to a 90 MHz Pentium Medilla programming on that. It was on the 90 megahertz principle. These were the main consumer computers at the time, and I'd optimized the Unreal Engine software render on that, which was the Pentium was the first superscalar architecture in consumer computing. It could run up to two instructions at a time. And if you wrote your assembly code very carefully, you could get absolute maximum throughput. So I got into my texture mapping code down to six CPU cycles, comprising 11 instructions. And that was required for every pixel on the screen. And that was just enough performance to deliver that. But Dell came out with these new workstations, and Intel had just launched the Pentium Pro, the first out-of-order processor. And so I basically bought the absolute MacSon.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Being pretty lazy, I'd had a bunch of like, I bought used computers because you'd often get them at half the price of a new one. They'd be good enough. So I had this old 486 I was developing on. I guess it was a 15-inch monitor at the time. It was a poor workstation setup, but it was very economical. So as we started on Unreal, I realized that I had to write a ton of code. I had to write it at absolute maximum proactivity. So I had to rearrange my entire life around delivering maximum output. And so at that point, I realized actually spending money on getting good equipment was a good investment. And we're not talking about millions of dollars here or billions if you're building a GPU farm. We're just talking about buying some basic hardware. And so I bought the biggest CRT you could buy at the time because this was a CRT year. It was 24 inches. It weighed like 100 pounds. I had back pain for a week after I installed it, but it got me 1920 by”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Yeah, yeah, it's because it solves all the problems at scale, often through manual pain, but always solves them. Love other languages do better and love theoretical aspects and are better for some usage cases, but you can't do everything. And that's really, very limiting.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Grown up learning with Pascal as my favorite language. In order to just get maximum performance and get the latest operating system features, I had to move to C for my second game, Joel of the Jungle. Nintendo style platformer. And so when I started on Real Engine, it was on 16-bit Windows using the C programming language. And over the course of the first year, it moved to 32-bit using these DOS extenders and then using Windows NT. And I moved to the C++ language. just because it simplified the code so much went from a really complicated pile of code to a much simpler one making that transition and so the almost the entirety of unreal engine development about two and a half years of it was all in C++ 30 to bits completely state of the art then like 30 to bit protected mode was kind of a magical thing having come from the days when computers were much less reliable and crashed all the time”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Techno and development power of the company, and Mark Rain running the business part of it, doing deals and maxing out his credit card and going around the world bringing sources of revenue to keep the company funded.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“I found I always need eight or nine hours of sleep a night without good sleep I would just become a zombie and wouldn't be nearly at my best. So I always needed to get sleep. I didn't need anything else going on so the programming itself was so energizing and thralling. So it was three and a half years of that during the project. Mostly spent programming. I would say probably 60 hours a week of programming, five hours a week of coordinating with other people and iterating and sitting down with them and looking at what's going on in screen and figuring out what they needed. Maybe five hours of business stuff. And you know, there's a good division at labor then. Didn't have a big executive team, but it was basically myself.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Well, we'd all gravitated towards a schedule, a work schedule that maximized productivity, and that usually meant waking up late. I get to get to work around noon, usually work till 2 a.m. or so, 3 a.m. sometimes. I didn't have anything else going on in my life, so here's why you just work and sleep and occasional eating and, uh,”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Like, oh, I see what you need now. We'd constantly be improving the tools, and just the iterative process and the speed at which that improves products is the critical element to success in games. The slower the iteration cycle, if you make a build every week and you prove you go through one iteration every week, you're going to be way, way, way worse by the end of your project than a game company that makes new stuff every day. That was the magic that happened together. And there was really nothing but passion in everybody's individual dedication to it that made it work.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Epic had grown organically by recruiting people with awesome talent. We always had a limited budget. We could never pay to bid up people with salaries and hire them way by paying them more. We just had to find awesome people who were at the beginning of their career and put them together. And so everybody was very new to this and didn't have any assumptions about how companies worked. And so you put all these people together. It was really a constant interplay of talent as people were learning how to work together as a team. Nobody had management experience. Most people hadn't chip at a game before they worked with Epic. And we were figuring out as we went. But it was a constant iterative cycle. We'd make several new versions of the game every day. We new compile, introduce a new feature, or fix some bugs, get it to artists, artists improved their levels, continue building stuff, and then we see what they're doing on their level.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“That's one of the really unique things exist in gaming, not in normal big tech companies, which are just engineering and business driven, but gaming really does require all the best people across all the creative disciplines working together.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“And that's Epic has often done things that. Companies will have failed at, and we succeed not because of awesome management or awesome planning or awesome financing, but because of the sheer talent and willpower of the people involved to make it happen.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“The thing that was continually really interesting was the ongoing discovery of new techniques as we went, because at the time Quake had chipped, it had a little bit of dynamic lighting, Unreal really pushed dynamic lighting much higher than anybody else had done before having colored dynamic lights with some shadow casting capabilities statically or moving lights without shadows and figured out how to do a 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 level. Whole of amazing techniques came together to build a game that made a number of leaps ahead of the stay of the art at the time. Yeah, it was really crazy, but I think most companies wouldn't have survived that, but the sheer talent of the people involved made it possible.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“We were always very financially stressed. So I was continually worried about debt. I had total confidence though that we'd work out all of the technical and artistic problems because we knew the pieces and it was largely a matter of typing code in and solving some problems. And kind of like we knew we could ship a version of it.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“We barely survived and almost ran out of money a number of times, but somehow we always pulled through. And it was a crazy project because it was three and a half years of development in a game that we always thought was six months from shipping. And it was like three and a half years of 70 or 80 hour weeks for most everybody working on the project. Not even knowing what problems we'd need to solve next because we were so immersed in the current ones.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“And so he was initially going to write the 3D engine and was going to write the editor. He sent me his code so I could integrate into the editor. It was just a giant pile of assembly code. I was like, hmm, why don't I just write this myself? And so James instead started going off and building 3D models and 3D animations using the tools at the time. And so Cliff, who'd done a lot of design work and built the levels on jazz jacket, went off and started learning basics of level design. And so I was writing this editor and Cliff Lezinski was customer number one for it, starting to go off and build levels. And James Schmotz was doing awesome creatures, sending them to me, I'd get them implemented in game, and we brought on an animator to bring them to life. And we brought in more and more people until at the peak of Unreal One development, we had about 20 people working on it, which was a huge team for the time. It was a really stretching epic finances nearly to the breaking point.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“Everybody had won in an awesome pinball game. Massively successful, but it was Was a multi-lidisciplinary person. He wrote The Code for the Game, the Art for the Game, and did basically everything. And the code was 30,000 lines of assembly language.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source
“So a bunch of us epic independently went off and started writing our own 3D graphics code to figure it out. We found at one point we had a number of people dabbling in this doing different parts of it. And at that point, we decide, okay, this is 3D graphics and 3D gaming is going to completely change the world. We need to go all in on this. And so we took the best people from our best 2D game development teams and put them all together to make a 3D game. We didn't really know what we were doing at the time. None of us had ever shipped a 3D game, and most of us were still learning, but everybody was like trying different disciplines to see what they were best at. And it was a combination of a bunch of people who came together to make Unreal. I didn't initially volunteered to make the 3D editor for the thing. And James Schmott, who had made Epic Pinball. Epic Pinball. Now, that wasn't a crazy game. This was one of the 2D sharer games. He made it while he was in college, and he was making like $30,000 a month from the royalties from this game.”
2025-04-30 · Lex Fridman Podcast · #467 – Tim Sweeney: Fortnite, Unreal Engine, and the Future of Gaming · IDENTIFIED FROM THE TRANSCRIPT · source