Patrons can now vote for the next video! Thank you for your support. Also, some additional links from the video: ❤Patreon: www.patreon.com/simondevyt 😍Courses: simondev.io WolfFire Games Article: blog.wolfire.com/2010/10/Imposters

This is the stuff about gamedev that almost nobody talks about, and if they do, it's way too indepth. I love channels like this. You're doing a lot for making people understand how complex and smart Game Engines and Render Tech actually are.

thank you so much for saying "impostor" at least a dozen times while not making a single among us reference, im proud of you

I like that Epic's approach to finding out that subpixel polygons kill render times isn't to tell artists to avoid intricate geometric detail and to make more LoDs, it's to double down and make a system that lets the artist go absolutely wild with detail and not need to even think about LoDs.

This also really helps explain how 4k gaming is possible on these GPUs. In terms of GPU usage efficiency, smaller pixels is effectively the same as having larger triangles. So while 4k screens have 4x as many pixels, you're also throwing away far less work that the GPU is doing, which helps regain some of the performance loss

One LOD technique I like a lot especially in the mobile world where nanite-like LOD engines currently aren't feasible is Progressively Ordered Primitives/POP buffers. The core idea is to cluster vertices through quantization at different levels of precision and sort them such that lower-precision vertices are first in the vertex list and higher-precision ones are last. The end-result is you can change the LOD of a model just by changing the quantization level and how many vertices you choose to draw without storing any more data than original mesh used. The benefit is four-fold: - Artists only need to make one model with any arbitrary attributes - Cracks/seams can be handled perfectly - Can have dynamically adjustable LOD levels without popping from mesh swaps - Can stream in the extra vertices as they're needed or upload the whole vertex buffer once and instance multiple LOD levels in one draw call. The latter is useful as draw calls are still disproportionately expensive on mobile. Since you're sorting the vertex list anyway (which can be done in O(n) time) and vertex order within quantization clusters doesn't matter much, you can also sort them on a secondary level to maximize vertex fetch efficiency which is important for mobile because of binning (more-so than overdraw since tile-based deferred renderers often have near-perfect hidden surface removal). The neat thing is you can scale the quantization level according to how large quantized grid would make triangles appear on screen to help maximize quad occupancy while maintaining enough detail for it to look good. It does have some drawbacks, notably that it doesn't play well with vertex skinning and lower LOD levels tend to have a bit more triangles than hand-made LODs, but it's great in a mobile environment or for procedural mesh LODs. As a side note, optimizing for mobile tile-based deferred-rendering is a lot of fun and it feels so much more rewarding to make a mobile engine run fast. Most mobile developers just port PC games or graphics techniques to mobile as-is and call it a day while limiting gameplay to negate poor performance; however, with careful optimization you can achieve between Xbox 360 and Xbox One levels of performance on most modern (>5 year old) mobile hardware. I'm definitely biased though as I've found my niche in mobile optimization.

14:30 the "maximum area" triangulation improving performance so much is news to me! I usually create slices since it looks "nicer", but I should probably think more about the final result.

I am an absolute novice at game dev whos been toying around in Unity and now Godot for about two years, and I have to say each one of your videos feels like I should be paying you for this kind of info. The fact that this is your FREE content is insane, and I'm excited to see what your paid content looks like. You have a knack for beginning small, simple, and approachable, and then expanding to the point that I'm pausing and writing things down and yet still not feeling overwhelmed. I've read through documentation and white papers before for plenty of other coding subjects, but nothing has ever made me WANT to like your videos do.

Ill confess, even up until about 10 minites in I has assumed, naively, that I did actually understand why billboards were so kuch better for performance, with thoughts along the line of "reading a precalculated viewing angle from a file/ram is MUCH cheaper than doing the matrix multiplication to calculate the physics perspective appearance of even a very low poly 3D mode". When you went through how the physically arcitexture of the GPU differently handles triangles with a size close to the pixel size, it was so mind-blowing. I haven't realised I was so starkly wrong about something in a while, such a great feeling!

Now send this to Mortal Kombat

Really enjoyed this! As an artist you get told what things to avoid - e.g. long thin triangles and extremely small triangles, but it's rare to get a good explainer on *why*.

One iconic example of billboards is the infamous 1000 Heartless fight in Kingdom Hearts 2. Back then, it would've been impossible to have 1000 entities individually moving and acting all at the same time. Square Enix's work around to this was to have only have a handful of active enemies actually nearby. Meanwhile, the rest of the Heartless would be represented by these 'billboards'. While in combat, it's hard to notice this detail at first, but it's extremely obvious on repeat playthroughs. This work around is also present when there's a swarm of Rapid Thrusters, except it's a lot less noticeable since the enemies are flying above you and often spawn offscreen rather than right in front of the player.

This is a very nice video! I have heard avoiding micro triangles is a big thing but now I finally know why

Wow, this really explains why Nanite was such a breakthrough, of course it doesn't dig into the difficulty of implementation, but it does show how it eliminates the excessive tiny triangle issue.

I don’t think I’ve seen anything that talk about this stuff in this much detail, much respect for your career choice, I am truly amazed at the information dump and how accessible you’ve made it, thank you.

“I’ve always been interested in optimizations” man I wish this was a requirement to work for any big game company 😭

this channel is insanely underrated. The amount of knowledge you offer with each video is absolutely great. Pleas keep this up.

Amazing. Not only does this explain why intuition fails, but you also back up the technical reasoning with real industry solutions. Watching your videos, I somehow always come out with more information than I was expecting. Well done!

The moment I saw the 2x2 grid in the thumbnail and you mentioned LODs I knew exactly that this is gonna be about workflow scheduling for fragment shaders. Great video as always

From one 20+ year dev to another, your content is solid. And thanks for mentioning ATI!

Thank you a ton for the captions, really made it much easier to follow! Great video :)

This is an amazing video. Really good information in a short and clear video. And this is information that is not found too often on UKposts. Much appreciated!

You have by far the best game optimization content I’ve come across, can really tell that you know what you’re talking about and not just repeating words said by someone else. Really love the way you explain things with just the right amount of information for you to be able to understand these things fundamentally and really grasp the mechanics 🙏🙏

Very well done. Even covered some stuff that never gets covered, like how billboards are used along with LOD and occlusion culling. They never talk about billboards. First time I made a model doing all this, I was floored at how well it worked. This stuff changed everything back in the day. You also said one of my favorite words, lol ... Automagically.

"Mommy, Daddy, where do pixels come from?" SimonDev: "Sit down son"

03:34 You just made my day for putting in Kai from the best TV Show ever made!

This video is an absolute gem, Really thank you Simon for putting this up and making this so straightforward. Really got some deep insights about how GPU's work.

been hoping for content like this for many years, great job

You're amazing, glad to have found this channel. Thank you for this easy to understand and useful information!

You are an excellent teacher, the language and presentation was so easy to process even though I am only tangentially related to the topic, thanks for making this!

Amazing video as always man! I have heard about this on the surface in my career, never found something that covers this subject with so much ease before, thanks

Amazing video. Really like when I stumble on such high quality content. Would really like a part 2 covering Nanite and maybe alternatives other people developed

Creators like you kept me motivated and today I'm a 3D and tech artist in my team. I'm not hardcore into graphics programming (yet) but I'm learning! One baby step at a time.

This is fascinating, and very helpful. Thank you!

This is fantastic, thank you Simon! Just bought both of your courses, looking forward to diving in.

Back in the ‘90s, Marathon used “imposters” for all of the moving characters. They were all sprites. Animated sprites with versions from 8 separate angles.

Thank you so so so much for this, this is extremely helpful!

Dude, this video is awesome! You have such a straightforward way to express your knowledge that I, not a graphics programmer, get it. Kudos!

Finally! I no longer have to explain this every other day. Another brilliant coverage, well executed.

Crazy informative video! Big props

This is a joy to watch! Glad I found this video 🙏🏼

I just found this through a reddit comment and I didn't knew how much I needed to know this. Thank so much for explaining. This is so valuable and I definetely will buy ad start with your game math course. Awesome stuff

Dude, amazing content. How interesting! Thx for sharing your knowledge, cheers!

This is so incredibly in-depth, I learned so much from this video

Wonderful technical deep dive. Great job 👏

You just explained what is, really, a constant, complex technical process, in a way pretty much anyone can follow and understand, and that's more than can be said for a lot of teachers/professors... I knew, for instance, a good amount of what was covered here, just accumulated knowledge over the years of gaming and satisfying my curiosity, and guessed cranking up sheer volume of triangles would tank FPS pretty quickly... But now, I actually understand *why*... Thanks for the insight 😍

Thank you Bob from Bobs burgers for explaining graphics optimization

Thanks, this was actually really interesting and helpful!

Absolutely love the way you explain things.

Brilliant explanation! Thank you

Thank you for this Video. This is such an eye opening thing! I would have never assumed that the rasterizer expects triangles that are atleast 4x4 pixels. I have always assumed, that is was a simple less stuff render

What a great video, I kinda always wanted to understand the performance optimization techniques better, but just didn't really had time to do the digging. Thank you for your effort!

That's a fantastic explanation, thank you!

Very interesting video, I’ve always wondered why more/smaller verticies were taxing on preformace and I’m glad that you made a video explaining it in a easy to understand manner

Great video :) This will be my go-to when people ask about mesh-related optimization!

In intro to 3D modelling we were told very sternly, "keep the triangle count to a minimum, and remove as many unnecessary triangles as possible. So this is nothing new to my ears... but it is fun to listen to anyways.

Very informative. I'm not a game developer but I enjoy understanding some of the complexities. I didn't realize that small triangles were an issue. Not being familiar with how gpu's work at that level of detail I'd figured a triangle is a triangle.

Man, thank you for your channel!

So interesting. Thanks for your work, I really appreciate it!

These are the kinds of videos that inspire me to one day dive into the graphics side of computers. I've always wanted to touch shaders and 3D modeling, but it has always felt beyond my understanding. This helps.

Thank you. Very well communicated. Much appreciated.

Awesome video man. Really well presented

Great stuff, thank you! I really should watch more of your videos ^^

my adblocker works completely fine, but for your videos I always pause my adblockers so that I watch the ads and support your wonderful content ✨✨

Awesome content, very informative ❤

wow this feels like a masterclass, subscribed

Simon! You are a saint! You even reference everything you mention. S tier content 👌

Amazing video. Very well explained. It's funny, that even though I already knew why rendering tiny triangles is a problem, I never made the connection that thats the reason why lod works so well

Loved the video ! thanks for the content :)

Great video, thank you!

Thanks for the video, very easy to understand and very interesting

It blows my mind... one more day that I realize I know nothing. Thank you very much!! Perfect explanation and quality like always.

this is a really good video and also i really like your voice. thank you for making this 😊

This sounds like H. Jon Benjamin is teaching me computer graphics, and it's amazing. Great explanation of 2x2 quads, friend! I'd never really understood how to optimize for them before and I'm already excited to apply some of these tips.

WELL PUT TOGETHER VIDEO 👍

Amazing teacher definitely gonna buy your courses

Great video, very technical but clear witch is really great ! If you like it, keep up the good work

because of you i found Lexx, been trying to find it for the past 15-20 years :D thank you, subscription deserved from all the info (and the extra one)!!!

I very much appreciate the time you take to do these breakdowns! There's always more to learn in the world of graphics programming - and it's a blessing to call it my career ^__^

this is awesome! thank you!

Great video!

This flipped a switch in my head; this all makes WAY more sense now! Thank you!

Thanks for the pretty helpful video)

so far the best ones I've seen were done using a shader, 2 depth maps and 2images. it's a custom thing players do for vrchat, and it's so good, that it looks like the actual object just with couple of glitches. the genius of it is that it can encode essentially a 3d video. so it's used for stage performances for low power headsets such as oculus rift.

Well you are really helping me develop my own game engine. Thanks a lot.

I’m so sad to hear about your esophagus cancer 😢. You’re my favorite youtuber I hope you get better soon!

Thanks for this deep dive. You should use frame time instead of FPS on your plots though. As FPS is a reciprocal and thus makes reading the plot much harder.

Very useful infos, many thanks!

Amazing informative video in my OpenGL and Vulkan journey. Thank you!

That's awesome content as always

Rare Lexx reference! Don't think some of us didn't spot that.

Thanks for mentioning life of a triangle.

The Crew Motorfest uses imposters (or, as I got to know them many years ago, sprites) for trees when you're using the map and zoom out. It's a nice throwback to when I started PC gaming.

This is golden content.

Great video, even tho I doubt I'll be working as a game dev. I am always happy to learn more about optimisation methods, who knows I might make my game as a small hobby passion project on the side

EPIC STUFF

freaking good video! thx!

Finally, I found another channel matching Acerola's level of quality and in-depth explanation 😄

Just love the John Carmack quote on the article 😂

Great video. While not the same thing, it does correlate a lot to polyline vertices reduction in some fields, because if at some given scale two vertices become the same pixel, all you get is "overdraw cost", to the point where dynamically generating a new LOD for that scale might be better performant and less costly over time.