I love this stuff! You guys should do more series documenting the evolution of specific rendering techniques/attempts at certain kinds of effects, sorta like the H2O video John did a while back.
Incredible work as always Alex! Even as an industry tech guy, I still learn so much from your videos. Keep being awesome! (Now to look into the viability of converting Turok PC over to a Path Tracer...)
I can't wait until the day when RTX will have so many rays possible that we'll be able to do the same kind of full scale path tracing that is even rare in CGI movies today due to how time consuming it is.
I am not sure it'll be an optimal use of resources, because a lot of the lighting can be "faked" pretty well with rasterization-based techniques. Having *fully* realtime global illumination (not just indirect lighting) is very exciting, but it could also be distracting in games and make it harder to play. Quake 2 RTX has some of that, where the lighting becomes too dynamic and the game world can go from pitch black to blindingly bright very quickly during frantic fights in tight spaces and it can have adverse effects on the gameplay IMO. Modern games use raytracing mostly to augment the rasterized image, not to replace it completely as that'd be unfeasible but also needlessly expansive even if possible - as Quake 2 RTX demonstrates IMO. I guess it is possible that the raytracing techniques and hardware will improve with time bringing both manufacturing and running cost down to the point where it becomes feasible to make raytracing-only games, and dropping a traditional rasterized lighting as a fallback. It'd be interesting to see what game designs could emerge from that, especially when the indie scene gets their hands on this technology.
@@unfa00 my point was that eventually, there will be no reason for those shortcuts, the power will be so good that it would be a waste not to go full multi bounce GI pathtracing all the time.
Man... imagine still being optimistic for a "better future" 😂 it's a race to the bottom dude IDK if you've been paying attention but success isn't achieved by those who work the hardest or push their medium to its limits. Success in 2023 comes from exploiting existing intellectual property for the lowest possible cost & selling that hackjob product to the massive audience of frachise fans (who have no standards or reservations about buy & playing a badly made game that's based on their favorite IP) LOL, wait... did you actually think anyone involved at the leadership level actually cares about making good games? Dude, almost all of those people retired/left the industry years ago. It's all about licensing existing assets & crunching disposable workers to make those licensed assets into a facsimile of a "game" with a "story" 🤣 "Imagine how good future games will look..." No. I don't think I will engage in this pointless thought experiment.
@@unfa00 Light baking is very resource and developement time intensive and will go away and be replaced by ray tracing as soon as the average gamer has hardware powerful enough to run that at normal framerate.
I used to be a student of the professor that invented SVOGI. Wild to think that it'd be implemented in video games through ray tracing just a few years later.
It’s still wild to me that real-time ray tracing exists in my (younger) life time. I thought I would be ranting to my grandkids “back in my day we had rasterized lighting and we liked it! None of this ray-traced 5000 fps retina projected images y’all have! Kinds these days are soft.” “Mom! Grandpas ranting about having to walk up hill both ways in the snow to pay 2 times MSRP for a used 1080 Ti again.” “Calm down dad or you’ll spike your blood pressure again.”
@@TheCrewExpendableThis is due to the use of complex algorithms such as ReSTIR GI. Roughly speaking, light sources are assigned a weight and the few rays are concentrated mainly on the areas that have the greatest weight, i.e. are the brightest and most promising. In addition, spatial and temporal information is collected and reused. This is the reason for the noise and ghosting, but is several hundered times faster. In the traditional Monte Carlo method used in online rendering, the rays are distributed randomly and evenly across the scene. This is an unbiased method and is exorbitantly more expensive, but of course produces increasingly better results the more samples and bounces are used with diminishing returns of course.
I'm surprised there was no mention of SSGI, either the UE4 implementation found in Gears 5 and Days Gone or Pascal Gilcher's Reshade implementation. It's that missing link between ray tracing and rasterisation that perfectly demonstrates the limitations of the latter.
How does it perfectly demonstrate the limitations of rasterization? RTGI itself is already a perfect example of that and SSGI is just a downgraded version of that, and thus doesn't show the difference as much. It's still a pretty nice thing to have and is a decent solution to add on top of existing lighting if full RTGI is too demanding.
@@okaybutwhythough7456 SSGI is a post process and can only work on the limited information available in the framebuffer. It exhibits artefacts due to missing information from surfaces being off-screen or occluded causing the indirect lighting it produces to change radically as different pixels become visible, even from relatively small camera movements. It's really a very poor and unstable approximation of GI compared to any other method.
@@okaybutwhythough7456 rasterisation works by sampling the scene at each visible pixel on each visible triangle. At the time of shading it doesn't know anything about any other points on any other surfaces, let alone how much light they might be reflecting toward it. To approximate GI you therefore have to sample back a pre-lit representation of the scene passed to the shader. SSGI makes a good example of this limitation because it traces/marches rays through a representation of the scene, similar to RTGI, but is limited by that representation having been rendered into a 2D image (with depth information). It's that lost information about the scene that is the key difference between rasterisation and ray tracing.
Global illumination is the most important part of modern game graphics in my opinion. Such a drastic change for people that can recognize fake/real lighting
The problem is that we've gotten so good at avoiding the problematic situations for traditional techniques that you really need to know the tech to understand when something's impressive.
@@SimonBuchanNz Yeah devs have gotten so good at 'faking it' that normies often don't notice. Even for a nerd like me, sometimes the difference is so slight I'd choose rasterised over RT just to get the extra performance. Depends on the game though, of course. I guess it will save loads of dev time though, and like all new tech the devs need to learn how to use it to get it looking its best. Plus, we're in a transitionary stage right now... One day, real-time ray-traced GI and reflections will become standard, like pixel shaders and normal maps are today. Will need hefty GPUs though!
We're only good at faking it in a very specific subset of games, typically games that can get away with baking most if not all of their lighting. In more dynamic games, many of the techniques that get close to full raytracing just aren't feasible due to the dynamic nature of the games, and so you're left with alternative techniques that just don't cut it, for one reason or another. GI especially is a hard one, because the only alternatives are generally slow (slower than even full raytracing, when you try to fit more geometry detail into them), and support a limited amount of bounces (1, 2 if you're lucky).
:O Which is the name of the song at the end of the video? :O I love it! :) EDIT: find it! "NVIDIA Tech-Demo: Blobby Dancer". I thought the music didn't belong in the video.
Know what'd be really fun to see? A ray-traced Doom 3. Substantially better quality models than Quake 2 with actual bumpmaps and such, but also it's a game with the harshest direct lighting in existence and global illumination would fix one of two primary complaints with the game (how goddamn black it is).
It'd easily be the most impressive way to show off what global illumination can do, especially as it was designed to have many moving light sources. Most other games since the late 90s at least attempted to approximate GI in some way, while Doom 3 just went "lolno, pitch-black ambient is all you get"
I understand the appeal but as TonkarzOfSolSystem said, the game would completely break as it'd lose its main feature: being afraid of what can come out of...pitch darkness. What could be interesting tho is raytraced shadows to get rid of those horrible shadow edges !
Sonic Unleashed is one of my favorite examples of games that used baked GI but incorporated one of the first examples of light probes to generate a GI look in dynamic objects
Lighting is the crucial baseline for human vision to perceive color, dimension, and depth. One of the reasons we're easily impressed by viewing a game scene with plenty of realistically arranged well-baked lightmaps, despite being static diffused lighting. Or why more stylized art direction like R&C Rift Apart can still feel incredibly sophisticated and immersive - our minds can suspend disbelief of the stylized presentation, yet still be dazzled by impressive lighting and ray-traced surfaces, as it communicates significant information and 'sense of place and time' to human perception of our surroundings.
We'll eventually see all games migrate to it as sufficient raytracing performance is available on lower and lower end cards and as the market share of non-raytracing cards shrinks. Sort of like how Doom 3 more or less sounded the death knell of DX7-class cards (though the popularity of the GF2-in-disguise GF4 MX required an exception). Metro Exodus might be the first game to require it (though that's actually debatable since the "non-enhanced" edition exists as the fallback), but there will be more, at an increasing rate, until all games do.
@@sushimshah2896 Technically yes but there are games with 60fps ray traced modes on console you just gotta make some smart optimizations to make it possible.
@@theninjamaster67 consoles most likely will see RTGI along with reflections and shadows in at least 3-4 years when RT techniques evolve enough to run on the weaker RT hardware. Granted the Xbox has the potential to do it earlier if DirectML delivers something close to DLSS.
I really enjoyed this. I’d highly recommend using Cycles and Eevee in Blender to showcase these effects, would really allow precise demonstration that some of the diagrams can’t easily convey. Especially things like screen space effects which were glossed over a bit.
isn't screen space basically cube mapping ? Edit, oh, no I was thinking about something else. Yes, screen space reflections are an entire different thing using a specific screen buffer to provide the colour data to other objects in the scene but mostly for reflections.
@@TheSliderW no, it’s basically in a very basic sense copy pasting what’s on the screen, that’s why the trees disappear when you look down at the water in a game like far cry. A cube map isn’t limited by screen space.
Coming from an environment artist working in dem vidjagaems, I just want to let you know how much I appreciate the research and attention to detail that you clearly put into the video. Great job!
We (I know it's a small %) certainly respect & appreciate all the work & attention to details game devs put into games. And I obviously like watching videos like these as well which point out such details
Love these videos not just for the content itself but the comment section is usually more chill with the more tech nerd types coming out and the gaming fanboys mostly gone.
One small correction, many games with only direct lighting don’t have pitch black shadows (unless we’re counting ambient light color). Shadow stencils in Doom 3 have that effect but shadow mapping is a second pass and the shadows generated there are overlaid on top of a color pass that’s already been made, and the devs get to decide how transparent those shadows are. Shadow mapping still uses only direct lighting though.
Stalker used photon Photon mapping not sure of the exact method they used in that game but the principle is a super light raycasting method to produce light map textures. You throw a small amount of rays from a light source into the scene using projection maps to figure out what direction to throw them (to save on costly rays, no randomness here). When it comes to bouncing the ray you generate a 'russian roulette' system to decide weather it's worth bothering and this means you don't have to calculate the rays lighting strength just average it from how many rays make the bounce. Given the aim is as few rays as possible and we add a tonne of bias to their direction and bounce chance using it for direct lighting is a no go and indirect lighting with accurate color takes almost as many rays as ray tracing but making large squares of different light values to layer on a scene is fairly quick and makes calculating caustics pretty easy too..I think its also used for sub-surface scattering in a lot of games. Theres a handful of freely available research papers on the subject from the 90s on the web, given I'm bound to be way too simple\out of date
It was a bit ambiguous to explain fill color after light maps even though fill color is the oldest technique in the list (predating even the direct illumination) but very well made video! Fill color is basically act drawing things as they are without any lightning calculations.
Wow, what was the song you used in the end credits? I would love to know what it is that sounded amazing! I wrote the lyrics down after listening to it a few times. "She's feeling dark. She's feeling dark tonight. She's dirt. Can you see it in her eyes? Hang to my arm and I'll take you out tonight. I am feeling alright..."
@@Jonen560ti Thanks so much! Still not a very long song like less than a min and half, and no closer to figuring out who sang it. Seems to maybe be a fully commissioned song for this tech demo.
@@BFKAnthony817 I suspect it might have been intended for the Nvidia Dusk tech demo. The lyrics seem fitting for Dusk as a character and the music in the demo sounds similar to the Blobby dancer song, but without vocals. The Song also lasts about as long as the Dusk demo itself, about 1 minute and 38 seconds. Perfectly timed to end as the dusk demo fades to black. I can only guess the song was intended for Dusk, but they decided to go for an instrumental version and instead put the vocals in the Blobby dancer demo, which came out around the same time
@@Jonen560ti Wow that is incredible! First of all you can tell the music from that is very similar as well. I did just open up the 2 tech demos in 2 windows and muted the sound on the Dusk demo and played the audio form the Blobby demo. Your theory seems sane to me. I think it lined up well with it and syncs perfectly. Anyways, would be cool if somebody made an extended remix of the song, or even a normal remix. I think it is catchy as hell and fits in with the modern Retro Wave/Dark Wave music genres. Pretty cool for being from the early to mid 2000's. Yet still has that 80's New Wave Pop/Dance feel to it.
@@BFKAnthony817 I tried Nvidia's tech demos back to back when I first got an Nvidia card. Having ran Dusk and Blobby back to back, I quickly realized the Blobbydancer lyrics fit Dusk perfectly. If I still have the Dusk demo files on my PC somewhere, I'l see if maybe the composer is credited somewhere
Holy shit, this is one of the best videos you guys have done, also special thanks to Alex for his in depth presentation it really seemed like a single take :o Auf Wiedersehn!
They've covered SSGI in several videos. VXGI is Voxel Cone Tracing and as far as I know they haven't covered it, but they have covered similar solutions like CryEngine's SVOGI and Lumen, which partially uses voxels. It wasn't a full on in-depth coverage but it was still pretty decent. In short SSGI is pretty limited while VXGI/SVOGI are not as precise as full RTGI.
I mean the example at 32:19 kinda demonstrates at the same time the horrible accuracy of screen space effects. The version with SSAO "corrects" some of the shadows on the barrels but it also introduces ENTIRELY wrong shadows. Just look at the right side of the blue car. Oh my goodness does that look awful. The grass has like "shadows" that are not right at all. It seems more like it just outlines everything with shadows with very poor accuracy.
Path ray tracing is the holy grail for direct and indirect lighting. Not sure how many years until say a US$300 video card will get 60 fps on something like Cyberpunk 2077 with path ray tracing. I'd guess 5-10 years.
Could you talk about Ray tracing a little more technicallly? Like talk about the rendering equation and octrees. Also, could you explain other types of global Illumination like radiosity and MEMLT, please?
Wow, that was by far the best video on this topic I've ever seen. It's a little disappointing to see this has a lower view count than so many DF videos though. It really just seems like an immense amount of work to make something like this and I don't want them to ever feel like the investment isn't worth it. (Hopefully, more of the average subscribers decide to click on this after they calm down from that new Richard meme or console war ammunition they think they found) :p
This is incredible work, Alex. I need to watch it like three more times to retain it all, but if I was a teacher I would proudly show this to my class. Well done!
This was fantastic! I'd love to see a similar Tech focus episode looking at the evolution of shaders and the hardware they run on, from pre DX9c fixed function HW with non-programable shaders, through the DX10 era with the G80/HD series cards up to modern DX12 stuff :)
I absolutely love this. Would love even more detailed breakdowns of complex topics in lighting, materials (PBR in particular), evolutions in modeling, etc. Great work!
Have you calibrated your display ? having it professionally done can be worth the expense depending on your display. The Spears & Munsil discs are a great easy to use alternative for about $35. I haven't seen it running on PS5 in person yet, the difference on PC is pretty stellar imo.
Awesome job Alex! Also I remember my first time seeing that corridor in Half-Life 2, even as a kid I was thought it looked so amazing and realistic 16:14
Lumen is not as precise but runs a lot better and doesn't require hardware acceleration. Pretty much sums it up. It just uses and combines several different forms of tracing instead of triangle tracing like RTGI.
The simplest way I can describe it is, raytracing is a naturally emergent algorithm. By just adding a few simple rules that govern how a ray interacts with a surface, many kinds of lighting phenomena (ie graphical effects) naturally emerge. By allowing a ray to hit a surface, lose a portion of its energy to the surface, then bounce off in another direction, you immediately get direct lighting including shading (what the rasterised direct lighting of this video showed) and shadowing (this video didn't show this, but shadowing doesn't come naturally with rasterisation, it's a separate effect that has to be calculated separately and blended in with your direct lighting), as well as indirect lighting. By allowing a ray to hit a surface, lose a portion of its energy to the surface following a different mathematical formula, then reflecting off the surface in a specific direction based on the angle it hit the surface at, you immediately get reflections (which immediately have correct lighting for the reflected objects, because the reflected ray will still follow the above rule), and reflective caustics (basically the other way -- an indirect lighting ray hits a reflective surface, which then follows this rule to produce a reflection, leading to a bright streak being emitted by the reflective surface). By allowing a ray to hit a surface, then enter the surface in a specific direction based on what angle it hit the surface at, you immediately get refraction (which, *again*, will immediately have correct lighting of whatever's being shown through the refractive surface, *and* you also naturally get total internal reflection thanks to the second rule), as well as refractive caustics (exactly like reflective caustics, except this time the indirect lighting ray hits a refractive surface, which then follows this rule to produce a refraction, leading to patterns being projected onto the original surface, like the patterns at the bottom of a pool). This simple algorithm comprised of just 3 basic rules that govern how a ray interacts with a surface, causes all these phenomena to naturally emerge, whereas with rasterisation, each of these would be their own completely separate effects, that are calculated independently and blended in with the rest of lighting. Hell, with rasterisation, some of these would just be impossible unless you went with lightmaps (such as reflective caustics), and the ones that remain won't interact with each other like they would with rasterisation (ie you couldn't have like a glass sphere showing total internal reflection of it's interior, which then refracts back out of the sphere to show a correctly lit wall behind you).
I think these are very important videos in the context of this channel. I think you guys overestimate the amount of people that actually understand what you talk about in your videos! I genuinely believe a large majority of your viewers are very casual with not much deep technical knowledge, who may not even understand any of the terms or techniques you discuss... so these videos are important ways to bring those viewers in even more.
My favorite content from this man. Do you think we could see one on the Nvidia/AMD control panel? Some options seem to do nothing or don't work in certain APIs.
I feel like the teleprompter didn't help Alex in this. I went on to check if the video was playing in the correct speed. 12:34 - Rave? Wait, no, _this_ is rave: 34:31 EDIT: Great work, though, Alex! That was a very good prime on indirect lighting techniques. The part with the examples on IBL reminded me of that Alfred Molina PS4 demo. Holy cow, I can't believe Rage came out ten years ago... It was mindblowing how good it looked. Well, apart from the animations.
am I the only one that likes games with normal mapping and pure "direct light" like doom 3 and Chronicles of Riddick? 🤔 it makes the game look so slick and polished
It is an interesting and crisp visual style, and really stands out among all the softer, less vivid graphics found in other games back then (with their blurry, baked-in lightmaps).
@@jrno93 I really need to get started on that one- it's been in my backlog for too long! The screenshots are already impressive, and it no doubt looks even better in full HD.
good video, very illuminating.
quite enlightening, isn't it?
shines some light on many details
it's nice to hear a good explanation from a bright person
it was definitely Alex's time to shine
Kill me
I love this stuff! You guys should do more series documenting the evolution of specific rendering techniques/attempts at certain kinds of effects, sorta like the H2O video John did a while back.
1 month ago but the video came out 7 hours ago??
@@ZK-ff2ru early access
@@ZK-ff2ru fear me mortal
Yes do more stuff like this!
100% agree!
Fantastic breakdown.
how is your reply one month ago when the video just came out? also love the quality you DF and harris heller bring to the platform. keep it up!
@@NubbinzGaming Early access
@@mikeuk666 Wouldn't really call the second part as some sort of a win and actually unncessary to even mention that.
@@gurkiratsingh8747 It's ok, you'll get to say First on the next one.
@@Taijifufu :D
This is one of those videos I could watch many times over and always learn something. So much great information packed into this. Great work!
Incredible work as always Alex!
Even as an industry tech guy, I still learn so much from your videos.
Keep being awesome!
(Now to look into the viability of converting Turok PC over to a Path Tracer...)
Tech Focus is back baby!
Alex knows his shit. Great video as always!
I can't wait until the day when RTX will have so many rays possible that we'll be able to do the same kind of full scale path tracing that is even rare in CGI movies today due to how time consuming it is.
I am not sure it'll be an optimal use of resources, because a lot of the lighting can be "faked" pretty well with rasterization-based techniques. Having *fully* realtime global illumination (not just indirect lighting) is very exciting, but it could also be distracting in games and make it harder to play. Quake 2 RTX has some of that, where the lighting becomes too dynamic and the game world can go from pitch black to blindingly bright very quickly during frantic fights in tight spaces and it can have adverse effects on the gameplay IMO.
Modern games use raytracing mostly to augment the rasterized image, not to replace it completely as that'd be unfeasible but also needlessly expansive even if possible - as Quake 2 RTX demonstrates IMO. I guess it is possible that the raytracing techniques and hardware will improve with time bringing both manufacturing and running cost down to the point where it becomes feasible to make raytracing-only games, and dropping a traditional rasterized lighting as a fallback. It'd be interesting to see what game designs could emerge from that, especially when the indie scene gets their hands on this technology.
@@unfa00 my point was that eventually, there will be no reason for those shortcuts, the power will be so good that it would be a waste not to go full multi bounce GI pathtracing all the time.
Man... imagine still being optimistic for a "better future" 😂 it's a race to the bottom dude IDK if you've been paying attention but success isn't achieved by those who work the hardest or push their medium to its limits.
Success in 2023 comes from exploiting existing intellectual property for the lowest possible cost & selling that hackjob product to the massive audience of frachise fans (who have no standards or reservations about buy & playing a badly made game that's based on their favorite IP)
LOL, wait... did you actually think anyone involved at the leadership level actually cares about making good games? Dude, almost all of those people retired/left the industry years ago.
It's all about licensing existing assets & crunching disposable workers to make those licensed assets into a facsimile of a "game" with a "story" 🤣
"Imagine how good future games will look..."
No. I don't think I will engage in this pointless thought experiment.
@@Secret_TakodachiNone of that is true.
@@unfa00 Light baking is very resource and developement time intensive and will go away and be replaced by ray tracing as soon as the average gamer has hardware powerful enough to run that at normal framerate.
Thank you Alex, i am a layman in terms of technology so this was really interesting for me and easy to understand. Thanks homie 💕
Yea can't believe how easy it was to follow! Would've loved to have an explanation for svogi as well but maybe next time
10:22 who else has that StarCraft theme burned into their skull?
This guy!!! ;-P
Terran Theme 1, my favourite!
Was looking for this comment.
My exact thought! Glad I wasn't the only one!
Now I have to find the track to get it out of my head lol
I used to be a student of the professor that invented SVOGI. Wild to think that it'd be implemented in video games through ray tracing just a few years later.
It’s still wild to me that real-time ray tracing exists in my (younger) life time. I thought I would be ranting to my grandkids “back in my day we had rasterized lighting and we liked it! None of this ray-traced 5000 fps retina projected images y’all have! Kinds these days are soft.”
“Mom! Grandpas ranting about having to walk up hill both ways in the snow to pay 2 times MSRP for a used 1080 Ti again.”
“Calm down dad or you’ll spike your blood pressure again.”
Yeah I really hoped he at least mentioned SVOGI, in fact I commented that I hope to see it even before watching the video
@@TheCrewExpendableThis is due to the use of complex algorithms such as ReSTIR GI. Roughly speaking, light sources are assigned a weight and the few rays are concentrated mainly on the areas that have the greatest weight, i.e. are the brightest and most promising. In addition, spatial and temporal information is collected and reused. This is the reason for the noise and ghosting, but is several hundered times faster. In the traditional Monte Carlo method used in online rendering, the rays are distributed randomly and evenly across the scene. This is an unbiased method and is exorbitantly more expensive, but of course produces increasingly better results the more samples and bounces are used with diminishing returns of course.
Nice, Remember Me, what a deep cut
Remember Me was also one of the first games (maybe the first?) to have a fully PBR pipeline. Still looks spectacular to this day.
@@soumyajitdeb3943 what is PBR? Probe-Based Reflections?
@@x0b34rd4 Physically based rendering
17:33 is literally what Venus looks like, due to the dense clouds and no bounced lighting from nearby objects.
I'm surprised there was no mention of SSGI, either the UE4 implementation found in Gears 5 and Days Gone or Pascal Gilcher's Reshade implementation. It's that missing link between ray tracing and rasterisation that perfectly demonstrates the limitations of the latter.
How does it perfectly demonstrate the limitations of rasterization?
RTGI itself is already a perfect example of that and SSGI is just a downgraded version of that, and thus doesn't show the difference as much.
It's still a pretty nice thing to have and is a decent solution to add on top of existing lighting if full RTGI is too demanding.
@@okaybutwhythough7456 SSGI is a post process and can only work on the limited information available in the framebuffer. It exhibits artefacts due to missing information from surfaces being off-screen or occluded causing the indirect lighting it produces to change radically as different pixels become visible, even from relatively small camera movements. It's really a very poor and unstable approximation of GI compared to any other method.
@@faustianblur1798
Then what were you on about talking about how it perfectly demonstrated the limitations of rasterization?
@@okaybutwhythough7456 rasterisation works by sampling the scene at each visible pixel on each visible triangle. At the time of shading it doesn't know anything about any other points on any other surfaces, let alone how much light they might be reflecting toward it. To approximate GI you therefore have to sample back a pre-lit representation of the scene passed to the shader.
SSGI makes a good example of this limitation because it traces/marches rays through a representation of the scene, similar to RTGI, but is limited by that representation having been rendered into a 2D image (with depth information). It's that lost information about the scene that is the key difference between rasterisation and ray tracing.
@@faustianblur1798 Yes but at that point just using full on RTGI as an example works better than SSGI.
Yay been looking forward to this since it was announced
Global illumination is the most important part of modern game graphics in my opinion. Such a drastic change for people that can recognize fake/real lighting
Totally agree. It's the thing I'm most excited about regarding graphics technology.
The problem is that we've gotten so good at avoiding the problematic situations for traditional techniques that you really need to know the tech to understand when something's impressive.
@@SimonBuchanNz Yeah devs have gotten so good at 'faking it' that normies often don't notice. Even for a nerd like me, sometimes the difference is so slight I'd choose rasterised over RT just to get the extra performance. Depends on the game though, of course. I guess it will save loads of dev time though, and like all new tech the devs need to learn how to use it to get it looking its best.
Plus, we're in a transitionary stage right now... One day, real-time ray-traced GI and reflections will become standard, like pixel shaders and normal maps are today. Will need hefty GPUs though!
We're only good at faking it in a very specific subset of games, typically games that can get away with baking most if not all of their lighting. In more dynamic games, many of the techniques that get close to full raytracing just aren't feasible due to the dynamic nature of the games, and so you're left with alternative techniques that just don't cut it, for one reason or another. GI especially is a hard one, because the only alternatives are generally slow (slower than even full raytracing, when you try to fit more geometry detail into them), and support a limited amount of bounces (1, 2 if you're lucky).
2:10 'Perfectly Dark', pops in a photo from Perfect Dark, hahaha, I love Alex's humour and his effort to insert such details
9:01 Pitch Black reference with Vin Diesel too
@@MediaBrad you don't need bounce lighting when you have _family_
@@moosemaimer That whole “family” BS meme was cooked up by FF marketing department. They astroturfed Reddit hard with that shitty meme
@@Psyopcyclops took a page from the Sonic movie I see
:O Which is the name of the song at the end of the video? :O I love it! :)
EDIT: find it! "NVIDIA Tech-Demo: Blobby Dancer". I thought the music didn't belong in the video.
One thing this channel has taught me is that a lot of technical terms about gaming are incredibly straightforward.
Know what'd be really fun to see? A ray-traced Doom 3. Substantially better quality models than Quake 2 with actual bumpmaps and such, but also it's a game with the harshest direct lighting in existence and global illumination would fix one of two primary complaints with the game (how goddamn black it is).
The other thing is the movespeed and mechanics, which I doubt would change lol
Since Doom 2016 was a reboot, this seems unlikely. Maybe a prequel with a Doom 3 level design would work though.
The game isn't designed for less blackness. It would be an interesting tech demo but as a game it would only be fun by chance.
It'd easily be the most impressive way to show off what global illumination can do, especially as it was designed to have many moving light sources. Most other games since the late 90s at least attempted to approximate GI in some way, while Doom 3 just went "lolno, pitch-black ambient is all you get"
I understand the appeal but as TonkarzOfSolSystem said, the game would completely break as it'd lose its main feature: being afraid of what can come out of...pitch darkness.
What could be interesting tho is raytraced shadows to get rid of those horrible shadow edges !
Sonic Unleashed is one of my favorite examples of games that used baked GI but incorporated one of the first examples of light probes to generate a GI look in dynamic objects
Lighting is the crucial baseline for human vision to perceive color, dimension, and depth. One of the reasons we're easily impressed by viewing a game scene with plenty of realistically arranged well-baked lightmaps, despite being static diffused lighting. Or why more stylized art direction like R&C Rift Apart can still feel incredibly sophisticated and immersive - our minds can suspend disbelief of the stylized presentation, yet still be dazzled by impressive lighting and ray-traced surfaces, as it communicates significant information and 'sense of place and time' to human perception of our surroundings.
It's the most taxing ray tracing effect it's crazy that metro exodus has it on console especially being 60fps and the resolution it's at.
Really hope other developers see that it's possible and try to use the same approach
We'll eventually see all games migrate to it as sufficient raytracing performance is available on lower and lower end cards and as the market share of non-raytracing cards shrinks. Sort of like how Doom 3 more or less sounded the death knell of DX7-class cards (though the popularity of the GF2-in-disguise GF4 MX required an exception). Metro Exodus might be the first game to require it (though that's actually debatable since the "non-enhanced" edition exists as the fallback), but there will be more, at an increasing rate, until all games do.
Isn't RT reflections more taxing?
@@sushimshah2896 Technically yes but there are games with 60fps ray traced modes on console you just gotta make some smart optimizations to make it possible.
@@theninjamaster67 consoles most likely will see RTGI along with reflections and shadows in at least 3-4 years when RT techniques evolve enough to run on the weaker RT hardware. Granted the Xbox has the potential to do it earlier if DirectML delivers something close to DLSS.
What about SVOGI and Voxel Cone Tracing?
I wish you had showed some examples from Sonic Unleashed, given just how high quality its prebaked and dynamic lighting was for a 2008 game.
very underrated video unfortunately
i hope youll have more time to make more 'tech focus' videos in the future
I really enjoyed this. I’d highly recommend using Cycles and Eevee in Blender to showcase these effects, would really allow precise demonstration that some of the diagrams can’t easily convey. Especially things like screen space effects which were glossed over a bit.
isn't screen space basically cube mapping ?
Edit, oh, no I was thinking about something else. Yes, screen space reflections are an entire different thing using a specific screen buffer to provide the colour data to other objects in the scene but mostly for reflections.
@@TheSliderW no, it’s basically in a very basic sense copy pasting what’s on the screen, that’s why the trees disappear when you look down at the water in a game like far cry. A cube map isn’t limited by screen space.
The Outro Song was amazing ahahaha
Coming from an environment artist working in dem vidjagaems, I just want to let you know how much I appreciate the research and attention to detail that you clearly put into the video. Great job!
We (I know it's a small %) certainly respect & appreciate all the work & attention to details game devs put into games.
And I obviously like watching videos like these as well which point out such details
Love these videos not just for the content itself but the comment section is usually more chill with the more tech nerd types coming out and the gaming fanboys mostly gone.
your favorite game sux balls
The developers of Sonic Colors Ultimate could learn something from this
One small correction, many games with only direct lighting don’t have pitch black shadows (unless we’re counting ambient light color). Shadow stencils in Doom 3 have that effect but shadow mapping is a second pass and the shadows generated there are overlaid on top of a color pass that’s already been made, and the devs get to decide how transparent those shadows are. Shadow mapping still uses only direct lighting though.
What is stalker 1 using for its GI?
Will DF cover physics and AI techniques?
Stalker used photon Photon mapping not sure of the exact method they used in that game but the principle is a super light raycasting method to produce light map textures.
You throw a small amount of rays from a light source into the scene using projection maps to figure out what direction to throw them (to save on costly rays, no randomness here). When it comes to bouncing the ray you generate a 'russian roulette' system to decide weather it's worth bothering and this means you don't have to calculate the rays lighting strength just average it from how many rays make the bounce.
Given the aim is as few rays as possible and we add a tonne of bias to their direction and bounce chance using it for direct lighting is a no go and indirect lighting with accurate color takes almost as many rays as ray tracing but making large squares of different light values to layer on a scene is fairly quick and makes calculating caustics pretty easy too..I think its also used for sub-surface scattering in a lot of games.
Theres a handful of freely available research papers on the subject from the 90s on the web, given I'm bound to be way too simple\out of date
10:21 That StarCraft/Brood War music brings back memories. *injects Stim pack*
0:50 I remember this, Remember Me
Alex and John make some of the most high quality videos on TH-cam, those guys are nuts
Amazing video, this helped me understand lighting in game development more.
35 minute Tech Focus? Yes pleaaaase.
Great video, any plans to follow this up with something regarding Unreal 5's Lumen approach to GI?
I still don't understand most of the video after watch twice.
It was a bit ambiguous to explain fill color after light maps even though fill color is the oldest technique in the list (predating even the direct illumination) but very well made video! Fill color is basically act drawing things as they are without any lightning calculations.
YEAH Ive been save from boredom now with this video i can distract myself for a while, thanks for such deepdives love the content and detail as always
Wow, what was the song you used in the end credits? I would love to know what it is that sounded amazing!
I wrote the lyrics down after listening to it a few times.
"She's feeling dark. She's feeling dark tonight. She's dirt. Can you see it in her eyes? Hang to my arm and I'll take you out tonight. I am feeling alright..."
You can hear it in Nvidia's "blobby dancer" tech demo. Where I think it originated from
@@Jonen560ti Thanks so much! Still not a very long song like less than a min and half, and no closer to figuring out who sang it. Seems to maybe be a fully commissioned song for this tech demo.
@@BFKAnthony817 I suspect it might have been intended for the Nvidia Dusk tech demo. The lyrics seem fitting for Dusk as a character and the music in the demo sounds similar to the Blobby dancer song, but without vocals. The Song also lasts about as long as the Dusk demo itself, about 1 minute and 38 seconds. Perfectly timed to end as the dusk demo fades to black. I can only guess the song was intended for Dusk, but they decided to go for an instrumental version and instead put the vocals in the Blobby dancer demo, which came out around the same time
@@Jonen560ti Wow that is incredible! First of all you can tell the music from that is very similar as well. I did just open up the 2 tech demos in 2 windows and muted the sound on the Dusk demo and played the audio form the Blobby demo. Your theory seems sane to me. I think it lined up well with it and syncs perfectly.
Anyways, would be cool if somebody made an extended remix of the song, or even a normal remix. I think it is catchy as hell and fits in with the modern Retro Wave/Dark Wave music genres. Pretty cool for being from the early to mid 2000's. Yet still has that 80's New Wave Pop/Dance feel to it.
@@BFKAnthony817 I tried Nvidia's tech demos back to back when I first got an Nvidia card. Having ran Dusk and Blobby back to back, I quickly realized the Blobbydancer lyrics fit Dusk perfectly. If I still have the Dusk demo files on my PC somewhere, I'l see if maybe the composer is credited somewhere
Holy shit, this is one of the best videos you guys have done, also special thanks to Alex for his in depth presentation it really seemed like a single take :o Auf Wiedersehn!
Fantastic, thanks for this, was waiting for a new tech focus. Would be much appreciated if you did them more often.
A great example of light maps being used to a massive extent resulting in performance issues is AC Unity.
I wish y'all would've covered VXGI and SSGI
They've covered SSGI in several videos. VXGI is Voxel Cone Tracing and as far as I know they haven't covered it, but they have covered similar solutions like CryEngine's SVOGI and Lumen, which partially uses voxels. It wasn't a full on in-depth coverage but it was still pretty decent.
In short SSGI is pretty limited while VXGI/SVOGI are not as precise as full RTGI.
I mean the example at 32:19 kinda demonstrates at the same time the horrible accuracy of screen space effects. The version with SSAO "corrects" some of the shadows on the barrels but it also introduces ENTIRELY wrong shadows. Just look at the right side of the blue car. Oh my goodness does that look awful. The grass has like "shadows" that are not right at all. It seems more like it just outlines everything with shadows with very poor accuracy.
18:25 Wasn't expecting this naughty game to show up
Path ray tracing is the holy grail for direct and indirect lighting. Not sure how many years until say a US$300 video card will get 60 fps on something like Cyberpunk 2077 with path ray tracing. I'd guess 5-10 years.
Sexy Dural Gumby Euro Dance Party at the end seems very on brand for Alex.
Sounds Like Ray Tracing, Should Cut Down On Texture Memory, And Cut Down On Development Time Big Time Too😎👌
You don't need rasterization when you've got Family.
I will always appreciated an excellent Pitch Black reference.
I was missing Alex, great to have him back
wow! What a great video! It's detailed, well explained, and required a lot of work. Respect.
Could you talk about Ray tracing a little more technicallly? Like talk about the rendering equation and octrees. Also, could you explain other types of global Illumination like radiosity and MEMLT, please?
This is so detailed yet very accessible. Perfect technical communication.
Wow, that was by far the best video on this topic I've ever seen.
It's a little disappointing to see this has a lower view count than so many DF videos though. It really just seems like an immense amount of work to make something like this and I don't want them to ever feel like the investment isn't worth it.
(Hopefully, more of the average subscribers decide to click on this after they calm down from that new Richard meme or console war ammunition they think they found) :p
Great video, this shone some light on the topic. I feel brighter already.
Great shoutout to Remember Me!
This is incredible work, Alex. I need to watch it like three more times to retain it all, but if I was a teacher I would proudly show this to my class. Well done!
Hopefully more and more older games will be given raytracing patches in the next 5-10 years. It could really lift the look of a lot of games.
Great great video Alex ! Can someone tell me what song it is at the end of the vid with the bubble dancer ?
more tech focus please
This type of content is why we all love df
This was fantastic! I'd love to see a similar Tech focus episode looking at the evolution of shaders and the hardware they run on, from pre DX9c fixed function HW with non-programable shaders, through the DX10 era with the G80/HD series cards up to modern DX12 stuff :)
I absolutely love this. Would love even more detailed breakdowns of complex topics in lighting, materials (PBR in particular), evolutions in modeling, etc. Great work!
Awesome breakdown! I dont get the downvotes, need a tinfoil hat to get an idea why 🤣
When you finally get an Ampere or RDNA2 GPU 34:49
Funnily enough, watching this while waiting for the lightmap bake to finish on a scene I'm working on
I like the callout comparison to cartoons, and don't think it's always a bad thing if the game design recognizes it.
Thank you for shedding light on this
13:20 Arguably all technical solutions to the problem of graphics impose game design and interactivity limitations.
Well explained. I love this type of content. Thanks a lot.
Damn, citations. Respect.
Also, it must have physically pained Alex to talk about GI for 35min without mentioning SVOGI.
I too was hoping for him to at least give a passing reference to *SVOGI*
Am I doing something wrong on Metro? It looks so ordinary on my PS5, and yes I got the PS5 version. lol.
Have you calibrated your display ? having it professionally done can be worth the expense depending on your display. The Spears & Munsil discs are a great easy to use alternative for about $35. I haven't seen it running on PS5 in person yet, the difference on PC is pretty stellar imo.
I feel enlightened after watching this video.
Please make more videos focused on the tech behind the games we play in the future.
Awesome job Alex! Also I remember my first time seeing that corridor in Half-Life 2, even as a kid I was thought it looked so amazing and realistic 16:14
Amazing. Would love a "Lumen vs Real-time raytracing" tech focus
Lumen is not as precise but runs a lot better and doesn't require hardware acceleration. Pretty much sums it up. It just uses and combines several different forms of tracing instead of triangle tracing like RTGI.
This video remembers me computer graphics 1, 2 course on university where we had to program a ray tracer.
Alex is back! Awesome video!
Thank you Alex and the rest of the team. I have learnt so much from you guys in the last couple of years.
You had to mention tlou p2 heh, no hate to you, just the game
Back in my day, we learned this as: specular + ambient + diffuse lighting sources
So Ray Traced: GI, shadows, and reflections is in essence a more accurate one size fits all solution?
The simplest way I can describe it is, raytracing is a naturally emergent algorithm. By just adding a few simple rules that govern how a ray interacts with a surface, many kinds of lighting phenomena (ie graphical effects) naturally emerge.
By allowing a ray to hit a surface, lose a portion of its energy to the surface, then bounce off in another direction, you immediately get direct lighting including shading (what the rasterised direct lighting of this video showed) and shadowing (this video didn't show this, but shadowing doesn't come naturally with rasterisation, it's a separate effect that has to be calculated separately and blended in with your direct lighting), as well as indirect lighting.
By allowing a ray to hit a surface, lose a portion of its energy to the surface following a different mathematical formula, then reflecting off the surface in a specific direction based on the angle it hit the surface at, you immediately get reflections (which immediately have correct lighting for the reflected objects, because the reflected ray will still follow the above rule), and reflective caustics (basically the other way -- an indirect lighting ray hits a reflective surface, which then follows this rule to produce a reflection, leading to a bright streak being emitted by the reflective surface).
By allowing a ray to hit a surface, then enter the surface in a specific direction based on what angle it hit the surface at, you immediately get refraction (which, *again*, will immediately have correct lighting of whatever's being shown through the refractive surface, *and* you also naturally get total internal reflection thanks to the second rule), as well as refractive caustics (exactly like reflective caustics, except this time the indirect lighting ray hits a refractive surface, which then follows this rule to produce a refraction, leading to patterns being projected onto the original surface, like the patterns at the bottom of a pool).
This simple algorithm comprised of just 3 basic rules that govern how a ray interacts with a surface, causes all these phenomena to naturally emerge, whereas with rasterisation, each of these would be their own completely separate effects, that are calculated independently and blended in with the rest of lighting. Hell, with rasterisation, some of these would just be impossible unless you went with lightmaps (such as reflective caustics), and the ones that remain won't interact with each other like they would with rasterisation (ie you couldn't have like a glass sphere showing total internal reflection of it's interior, which then refracts back out of the sphere to show a correctly lit wall behind you).
Remember Me is a CRIMINALLY unrecognised game.
tetris cd-i level 0 music
nice
I think these are very important videos in the context of this channel. I think you guys overestimate the amount of people that actually understand what you talk about in your videos! I genuinely believe a large majority of your viewers are very casual with not much deep technical knowledge, who may not even understand any of the terms or techniques you discuss... so these videos are important ways to bring those viewers in even more.
what technique is lumen in ue5?
The best of Alex.
I clicked on this video thinking it was a Technology Connections video. I’m not sure if I should be pleasantly surprised or mildly disappointed.
Easy mistake to make after "Brown: colour is weird."
My favorite content from this man.
Do you think we could see one on the Nvidia/AMD control panel? Some options seem to do nothing or don't work in certain APIs.
I feel like the teleprompter didn't help Alex in this. I went on to check if the video was playing in the correct speed.
12:34 - Rave? Wait, no, _this_ is rave: 34:31
EDIT: Great work, though, Alex! That was a very good prime on indirect lighting techniques. The part with the examples on IBL reminded me of that Alfred Molina PS4 demo.
Holy cow, I can't believe Rage came out ten years ago... It was mindblowing how good it looked. Well, apart from the animations.
am I the only one that likes games with normal mapping and pure "direct light" like doom 3 and Chronicles of Riddick? 🤔
it makes the game look so slick and polished
It is an interesting and crisp visual style, and really stands out among all the softer, less vivid graphics found in other games back then (with their blurry, baked-in lightmaps).
@@3dmarth I think chaos theory did it as well. it's what made the game so beautiful
@@jrno93 I really need to get started on that one- it's been in my backlog for too long!
The screenshots are already impressive, and it no doubt looks even better in full HD.
This is so elegantly laid out. Fantastic work!
More please.
Talk about reflections! SSR, Planar Reflections, Cubemaps, Raymarching, etc. (Indepth)
0:05 Big Giant Nvidia demo
This video is a month old??
Alex is able to cut his hair then grow it back between videos I see!
Would have liked to see also explanation of how SVOGI and the fantastic dynamic GI works in Kingdom Come Deliverance. And to hear more Quake 2 music.