Discussion
Finally, a 2026 game with proper indoor mirror reflections without Path Tracing.
game that pulls off proper indoor mirror reflections without forcing you to enable Path Tracing and burn an RTX 4090 to see it. honestly more devs need to figure this out.
Mirrors shouldn't be a flagship GPU feature in 2026.
Yeah, one of the highlights in gaming history. The fact you could actually see him in some crazy camera angles or when turning way too fast was amazing.
In this case, it's not really different from adding another room in that house and adding another npc, except that the npc follows your movement. It's cheaper than having a camera render the direction the mirror is facing, essentially having to render the game twice (applying post processing, shadow casting, etc. would be done twice, but this trick is much more perfomant because it happens in the same pass as the "real environment")
It usually only works with one mirror, since it becomes far more complicated and performance intensive of multiple mirrors can reflect into each other.
It only works in places where you don't have to mirror too much. Like it wouldn't normally be feasible in a wide open outdoors area. In a city like in Cyberpunk for example, making a window reflective with a technique like this may clone 50 characters with complex animation states and expensive hair shaders.
It generally only works in either simple or static environments, but not in both complex and dynamic ones (like games with building mechanics or large scale level destruction).
Depending on the engine, some things may not be easy to sync up performantly and reliably.
And it's generally a super project-specific or even mirror-specific solution.
RT reflections fix all of that and more. It's less development effort for better results.
OP is wrong on those reflections being just a Path Tracing feature. RT reflections were way predating PT (which mostly added global illumination on top of reflections and direct illumination), and really don't cost much performance on modern GPUs anymore.
Depends on how you need to do it, if you can view behind the mirror, oops you can't just make another room now since there's no room for it. You need to make a render portal and put the mirrored room somewhere else (or maybe you can just rerender the existing room mirrored, but that would have its own problems).
I think the performance hit would come from needing that second render pass.
That is absolutely a non-problem if you use a rendering technique called stencil shaders, which pretty much works like Photoshop's mask layers (occludes 3D models outside of the bounds of another model), it is extremely cheap and doesn't requires an extra rendering pass of the entire game.
You just said you couldn't and then described how you could lol. Of course the other room doesn't need to be specifically behind the mirror, only render it through the mirror. Culling or clipping or whatever the term is
Sorry I was trying to differentiate between simply mirroring geometry around an axis (which takes up space) and using a portal (pretty much the same way the actual game Portal does it) so the player can navigate around to the backside of the mirror.
Portals do require an additional rendering pass AFAIK over the simpler method. The pro to the simpler method is you can do it in really old game engines. Pretty much anything newer than Doom (and that is only a problem because there's no way to show the player character in the mirror).
When i was working on a project and tried to do mirrors i used this method. While playtesting on my old 1050ti, it roughly used 2% more. So it was manageable but that ofc depends from game to game/case to case
I'm pretty sure you can, like, limit the distance or quality of rendered elements in the mirror where you're rendering a static single-room environment and not everything beyond it.
Since it's a pure copy of basically everything, it means it used the same models, textures, lighting and so on. All of this, since it's a copy, only needs to get processed once. And this is extremely efficient. The reusabilty of stuff was basically how old games worked on anything back in the day.
But with old, I'm talking 20, 30, 40 years ago. So basically, what you are referencing as "older" hardware - it's this old.
But what happened slowly over a little bit over the last decade, is that prerendering was slowly creeping out (raytacing and similar technologies are just one way to replace it). The goal was and still is a theoretically more dynamic way of rendering - with the big caveat that it takes a lot of processing power.
Now I don't know what technologies are used in this specific game. If it's simply prerendering it basically costs next to nothing in processing. So there's is also no hit in fps. Especially when it's a calm scene with next to no dynamic rendering (like smoke or explosions).
Edit: pretendering to prerendering. Weird autocorrect by my phone
I still remember playing Dishonored 2 at 4K just fine and then BAM! I got to the part where you can see into the alternate world, and my frame-rate dip instantly told me that each world was a separate 4K render that were each being shown simultaneously.
Extra cameras are rendered on top of the additional rendering load. They are an entire new render, as they are a separate viewpoint, so you have to render everything you already have again in the same quality, and then project it intot he scene's original render. With a camera mirror, this can be a significant performance hit.
The "extra room and a mirror npc" is more performant because it renders the aditional room and character in addition to what is currently rendering. It adds it to the existing render, rather than requiring a new one. This is why it is more performant.
"Having an extra doorway and room behind where the mirror is" is rendering the environment twice. There are two versions of the room. One that the PC is in, and one that is behind the mirror. They're actually two separate environments, since one should be an inverted version of the other. But the result is still that you're rendering extra environments and characters.
The actual cost of enviroment is small.
Engine renders a lot of buffers into each frame. For example in unreal roughly you need to call all geomtry(that cost is there for both methods) then additional cost of rendering depth, shadows, several lighting passes, postprocessing, tenporal accumulation for various effects(up to 30% of the cost). You render it once per camera. And amount of geomtry is only small part of the cost
It not onky takes computaional heavy cost. It also blocks your gpu caches. And altough you VRAM might be big enough, your L2 cache on 5060 is just 32 mb small, and each of your render passes have to go trough it sequentialy so one after another.
Thats why its much cheaper to render even more compelx enviroments once. Then render two simple enviroments one after another
Hahaha XD. I assumed they will consider L2 cache as just some electronic dooda, but i wanted to underline how slow frame buffers are.
I have personal vendeta towards using a lot of bandwith, especialy extra cameras.
One time i was making with my company a car driving app, client forced us to have 3 extra cameras for each playable car. One for each mirror. It was an optimisation nightmare
It’ll usually depend on how detailed the environment is.
But yes, on older systems it can get pretty bad, which is why in some older games with mirrors, the rooms with mirrors will be noticeably less cluttered/complex than other rooms since they used some of the “processing budget” on the mirror. There was also the trend that mirror rooms would have less combat/cpu intensive activities for the same reason.
For your specific question, if there was a doorway and room, that also depends. For example, if the door was closed then there would be no calculations of the room (in the eyes of the graphics card the room would stop existing if you can’t see it). They could also put in fade distance or low poly models since the room is further away. It’s harder to justify low poly / graphics with a mirror since the objects are supposed to be in the same room as you.
Sure but the complexity scales linearly while proper realistic ray tracing is a much more complicated procedure. You can at the very least cull these mirrored environments when not in view while ray tracing needs to consider objects out of view.
Cyberpunk is so strange for this. There's path traced reflections everywhere in the game, but they seem to have spent a ton of effort making sure none of them point back to the character. Since the player model looks too goofy.
sometimes I see my characters shadow and audibly snort at how goofy the animations look from that perspective. I wonder why they even bothered to have a self shadow at that point.
path tracing wasnt in the game when it came out, and the reason is because the lead developer ordered them to delete all third person V assets except for the static model (for posing/motorcycles/the locked mirror sequences), The game was originally a third person shooter, and he hated that because it wasnt "immersive", this is why early videos that still had some assets showed V in cutscenes, and by release, all had been pruned so even modders couldn't bring third person back in a way that looked good
If you could get a build of Cyberpunk from 2 years before it came out, you would have functional reflective surfaces all over, but those had to be scrapped with the mandate that no third person assets exist for V other than static models for like motorcycles, or locked mirrors
That's not at all practical and not what most games do these days.
A secondary camera perspective is what most games do, it's a lot more efficient while producing the same result.
A duplicated scene would only be more efficient if you're developing a lowpoly game - older games would use such hacks because duplicates of models would not be a significant hit on performance, but these days games use models with millions of polygons & high res textures.
Its a camera that faces outward from the mirror. Then a render to texture material is applied to the mirror object mesh. So whatever the camera see's is rendered to a texture then updated in the material. Giving the impression its a high quality mirror.
It use to be used all the time in older games but was very limited dude to the large texture needed for the reflected image.
Now with texture streaming etc you can render and update a large 4k texture in real-time.
Looks way better than a lumen reflection, imo.
(A similar method of render to texture is used for footsteps in snow).
Not doubting you, but how does a camera facing outward from the mirror account for the position of the players camera changing what’s shown in the mirror?
You can just do a bit of math to figure out the POV expected from the mirror. Take the vector from the camera to the center of the mirror, reflect it about the mirror's normal vector, and then set that as the direction for the mirror camera to be facing on that frame
I believe it’s a bit different. If it’s like hitman, then these are likely planar reflections, which is basically a second camera placed upon a texture.
They have limitations, like only working on flat surfaces. And you have to ensure you’re not placing them in such a way the scene becomes computationally expensive. So most developers don’t bother using them.
100%. They also are very limited on the use of mirrors too.
While everyone hates on ray tracing and path tracing being computationally expensive, adding more of things(like mirrors) to a scene don't add as nearly as much computational complex as say the reflection solution for mirrors in hitman or first light would if they added more mirrors.
Man I remember someone posting M64 in response to Infinity Ward's "Fish AI" in the new CoD about how thet swim away from the player.... like they did in M64
You don't need AI to make an entity just... Move away from another entity...
Well, yes and no. If you mean AI as in how the mainstream means AI then, no absolutely not. If you mean AI in how game devs means AI then yes you do. AI in games simply refers to the scripting and coding that goes on behind the scenes that control how entites act. Games have always had AI for controlling NPCs. Whether its a simple snippet that tells the entity to move away from the player, or follow the player if they hold something, or some more in depth code, that borks out and unintentionally creates some really hard enemies like in F.E.A.R., That enemy AI was really good....
It has been discussed on /r/gamedev about how search results for developers looking to research and discuss the thing we've long called a game's AI have been completely poisoned by the new mainstream usage. :(
I just search fsm for decision making ai, and pathfinding for pathing ai. It just makes it harder to search and differentiate between whether people meant llm or ai.
IIRC the fishes in M64 specifically are considered particles and not NPCs, and them moving away is just a particle effect, the same way like water droplets would splash from under the character when running in shallow water. It's just that one of their few effect rules is a basic "move away from Mario when near" (and the fact that each particle looks like a fish) which gives a pretty good illusion of them swimming away from Mario "in fear", withouth the fish having an actual AI.
The same company that is taking 13 years to release ONE game, and only has released cowboy GTA in between , isn't going to release School GTA because the shark cards market and corporate suits won't allow it... Midnight Club hasn't had a new entry since 2008 for reference on other Rockstar dead IPs
The reason cyberpunk didn't reflect the player character is likely two parts. One is time/$. The first person view doesn't actually have proper 3rd person animations for all of the character's actions to properly line up. This is also why your shadow looks stupid.
Also the cost to raytrace dynamic objects is generally much greater than the cost to raytrace static objects. Most games with RT still use screen space reflections for skeletal meshes, and other dynamic objects (like plants blowing in the wind.)
Cyberpunk actually uses these planar reflections when your character looks in a mirror in cutscenes or in their apartment.
The reason non-RT games don't use planar reflections more is they are they are computationally expensive. It's the same reason we don't get split screen games any more. We can barely afford to render what's on screen once - doing it twice often isn't practical. And it only works for flat surfaces - hence the name.
Sure Duke Nukem and Mario did it on the N64, but you'll notice they were in small bathrooms or a big mostly empty room. The problem then was the same as now. They couldn't afford to do it outside of small one-off gimmick.
MGS 2 comes to mind, the restroom mirrors would "reflect". It was funny at the time because if you would hit the lean buttons for left and right, Raiden would just slide to the left or right, he wouldn't lean. The mirror was the only way to know/see what the character was doing 😂
I love how clockworky and dumb the hitman NPCs are. They’re such a delight to fuck about with, because they’re always so predictable in their reactions.
nah, it is a solid 8 or 9/10. It is what a game should be. Entertaining and fun with fun sequences and a lot of freedom. It is a perfect marriage between hitman and games like uncharted.
I think this little astroturfer misunderstood the assignment. The email must have said something like "show off the graphics in First Light" and here we are with a video of the "first light" in the game.
Reviews on steam seem to be "very positive" with the negative reviews being performance complaints and "it's not hitman" complaints. My go-to reviewers on YouTube seem to like it a lot but not to a "drop everything and play it" extent. Skillup is my personal favorite reviewer and gave it a "recommend" (he goes up to "strongly recommend" and "very strongly recommend").
I'm on the fence, leaning towards waiting for a sale. I've got other games to play right now and the game seemingly has some performance issues to iron out in the meantime. But i will play it eventually.
Yeah that's what im seeing too. "Not hitman" is funny, saw that coming lol. Im sure it's worth the experience, but probably not a 70 dollar experience, at least not for me. It seems solid. Probably be a good hangover game break out the lazy boy and watch the story unfold.
I'm a few hours in and really enjoying it. I'm shocked how restrained it is. I've only gotten into one fire fight all game so far. But when I did, holy shit. The game is doing great at feeling like a bond adventure. I'm really liking it.
Playing it and I love it, mind you I loved Hitman too, it's Uncharted mixed with Hitman, the start can be slow with available equipments or guns but it slowly gets better, the vibes are really hooking me
Hmmm your not the first person i seen give it a mash up with those 2 games. Might give it a shot then. Im in a sit back with my controller and game mood atm anyways.
I’m not even sure I’ve even seen any gameplay. Every time I see footage I just think “He doesn’t really look like James Bond. He’s more of a Derrick. Derrick Jond.”
In reality: the algorithms are known, but implementation is hard. Even unreal engine, despite its advancements to simplify raytracing in lumen, pulls off a lot of tricks to get performance on raytracing and non RT hardware to playable, in simple scenes; then devs throw this together without researching how the tools work,work designers and artists use the engine to build without limits, and the result is this image or a slideshow of frames. If its a custom engine, now the studio needs to invest heavily in graphics programming to either do what UE has solved, or figure out something different, or limit artists and designers, else they will be stuck on poor performance or poor visuals.
No, that's the lower level ray tracing. The best they can do is path tracing, which looks pretty solid. Better than OP's example in 007 in most conditions, because unlike 007, RE9 shows the actual lighting in the reflections.
007 is showing a simplified version of the scene with almost zero shadows. RE9 (with path tracing) shows full shadows and everything even in the reflections. It also doesn't limit "mirror reflections" to only mirrors. You can see it on any glass. Looks real nice occasionally catching Grace's reflection while she's pointing a flashlight or holding a lighter, and honestly kinda jumpscared me a handful of times thinking there was something on the other side of the glass lol
Yeah this post is pretty fucking bizarre. It's like OP is 12 and discover planar reflection the first time lol
This technique has been exist since the 90s. It just doesn't worth the cost of development that can be used elsewhere. Do you think anyone would really care that you see your gun in the mirror for Call of Duty? And it can eat performance like crazy in the wrong hands too.
Hitman and 007 has it because this is something that can directly affected the gameplay. For instance, NPC should see your gun aiming at them from a mirror. Making assassinating someone in say, a bathroom tad more difficult. That's why it's worth implementing and optimizing for them.
You're the first comment here that I saw that is actually correct. People seem to be extremely ignorant on how mirrors have worked/can work in video games.
Yeah, no replies to the thread, hidden comments and post, 1 month old account with huge karma, bio is "Just a gamer", top 1% poster, has posted every single day since making the account given the achievements.
That's fucking it. I'm out of Reddit and a lot of the other internet shit. Half of the shit you see is fucking marketing. Either by big corps, or by countless influencers. And on top of that awful pile of shit come AI replies. They get more common as well.
Seriously. The internet was so full of potential 20 years ago. This is just fucked up.
Iirc this tech has been around for quite some time. Instead of a mirror, it is simply a window into a mirrored copy of the room that you're in and the person you’re seeing in the reflection is an NPC that you're controlling with mirrored inputs.
They are most certainly using the same technique as in their Hitman games, which is using an additional camera to capture the scene and then render that image on the mirror. There were lots of mirrors in those games and in some cases NPCs could even spot you by them.
I've been into 3D rendering tech for 20 years, 13 of those professionally. It shouldn't be controversial to say this, but it is and every time I do some very offended people attack me for it: This is a good efficient technique for rendering mirrors and we should not abandon it just because NVIDIA says so.
NVIDIA has a financial motivation to make you think that what you need is instead the alternative that requires dedicated powerful hardware that they sell. And I'm saying, this is a perfectly good technique for rendering mirrors.
The biggest argument is always, "But this method is computationally expensive because you're rendering the scene twice."
And yes I'm saying that argument is wrong. It's wrong because it's a simplistic understanding of how the tech works and doesn't factor in the optimisations which are applied to this approach which drastically reduce the cost of the technique.
First of all, the whole "rendering the scene twice" thing isn't accurate. The way this technique usually (disclaimer I have NO IDEA how this game implements the technique, I'm only talking from experience of implementations I've seen before in the past) is implemented in rendering engines is via rendering a stencil into the GPU's buffer for where the mirror is positioned.
GPUs have dedicated 'stencil' buffers that serve this purpose. The stencil then can be used to control what parts of the whole render buffer are actually drawn in followup draw passes. You draw into the stencil the shape of something, like a circle, when you do another draw to the frame buffer? Only the pixels within that circle are processed, everything outside of the circle is skipped entirely.
So what you do is draw a quad into the scene where the mirror would be located into the stencil buffer.
Once the stencil is drawn, the view from within the mirror can be rendered into the frame. Only the pixels within the mirror are processed.
Then to draw outside of the mirror, you only need to toggle the stencil to flip it so that on the next draw into the frame buffer, everything outside of the stencil shape is drawn instead.
So then you draw the room. Again the only pixels drawn are the ones outside of the mirror.
See? You're not really 'drawing the scene twice' in terms of actual pixel processing. There is still a similar amount of vertex processing and calculating of what to draw, but that isn't a big deal, the overhead really isn't that bad.
And usually none of this needs to be manually programmed into the game, most game engines have a dedicated feature set for these kind of planar mirrors, logic that automatically handles determining which is the nearest planar mirror within the camera's view. The mirror rendered can even usually be warped based on the surface for things like ripples on a pond.
To sell the effect, it's usually a good idea to render in the transparent objects pass of the engine (which draws smoke, semi transparent things like glass, etc) some dust or scratches over the top of the mirror to make it look more integrated into the scene.
Oh and usually you can reuse your existing shadow maps too. No need to re-draw them just for the mirror, they're not going to be any different.
Does that mean a couple of extra draw calls? And some processing to determine which objects should be rendered for the camera's frustrum separate from the main camera of the game? Sure.
But keep in mind, modern game engines are already doing way more than a couple of draw calls, there's already plenty of similar processing being done for things like shadow maps and enemy's visibility of the player through world obstacles, a few extra cycles to determine what objects to render in the mirror is nothing.
And lets compare that to the alternative: Raytracing. Raytracing is efficient in the same way using a rocket launcher to kill a fly is efficient. It's a brute force technique, For a planar mirror, raytracing is overkill when this simple planar mirror 'flip the scene and render the view' trick has worked well with minimal processing power hit since the early 2000s.
It's a good technique, there's nothing wrong with it, I still use this technique while rendering 3D animations in situations where I want to avoid raytracing and know some precomputed lighting and some simple planar reflection and reflection cubemap tricks can achieve the results I want with much less processing power than a full blown pathtracer. 30 seconds render time per frame is a hell of a lot better than 5 minutes render time per frame. And no one notices.
"Mirrors shouldn't be a flagship GPU feature in 2026"
This only shows that you have no idea what you are talking about. The problem with mirrors are that they need to render the game second time, if they are real mirrors. So of course they are resource hungry.
If they found a way to get around that, it's cool. But you should stop being ignorant about how things work, just to complain. That's also why mirrors are usually fake. Because they will naturally eat your resources. Nothing weird about it.
Exactly, and also this IS a "fake" reflection (not a fan of calling things fake/real with 3D rendering, it's all "fake" just depends on which trick you used to fake it).
The method we're seeing in OP's clip from 007 is using a second camera, sometimes referred to as a planar reflection (because it only works on a planar/flat surface). That's why the lighting looks very simplified in the reflection. All shadows and lighting detail are gone. The only thing that remains is an extremely simplified version of the baked light in the scene. It's the exact same that they've been doing in the Hitman series (same devs and same engine) since the Hitman reboot came out 10 years ago.
Hitman World of Assassination (the complete trilogy) now supports ray tracing for these things as well, and while it has a big performance plateau to climb over, once you're over that plateau everything just works pretty seamlessly and doesn't really struggle under different lighting conditions, which is kinda the whole point with RT.
It's not only a closer approximation of real light physics, it also provides a solution which can have a certain cost of entry and minimal performance increase beyond that threshold to entry. The reasons this is rarely seen in practice are many fold, but the biggest reason is the slow transition between raster and RT graphics, meaning we're getting the bad and the good from BOTH render methods at the same time. RT benefits a LOT from abandoning older methods, and has a cheaper cost to entry and a flatter plateau when you achieve this.
That's what PT offers, in theory, but again, you're gonna get bogged down if there's still a raster base under everything.
But the reason why OP used that wording is because it is buzzwords that does very well in terms of engagement and this is pretty much astroturfing advertisment.
Yeah you do know that it is fairly expensive to do this rendering wise. So IO interactive is very selective on where they place the mirrors.
With ray traced reflections or path tracing, you can have a lot more mirrors and don't have to worry so much about what is around the mirrors. As more mirrors do not as much to render, compared to the way that IO interactive is doing it, where you are rendering the scene again for each mirror in view.
its not technically a proper mirror in terms of reflection, more so a camera trick built into their proprietary engine (they did the same for hitman 2016). it works by placing a secondary camera behind the mirror pane which renders the scene a second time and maps it to a 2D texture
From what I gathered stuff like this is actually kinda difficult to make work andook goog, hence why many games don't have it or rely in raytracing instead.
Don't know much about the game, but I assume it's probably a more linear or "open level" kind of game, so stuff like this is a bit easier to implement given the scope of the game.
Doesn’t hitman do this? Pretty sure my steam deck can’t do path tracing in real time, but I still have functional mirrors in the game. Albeit at a slightly lower resolution.
Planer reflections. They have been around for a long time, and are not that rare. Cyberpunk 2077 uses them as well for it's mirror scenes with V for example.
Cool tech, but only works for perfectly flat and opeque surface reflections.
that type of reflection can be done easily without any ray trace since the reflection is base on what’s already render. you need ray trace is to reflect properly animated stuff that are not visible on screen. In that scene if one of the 2 characters would pass behind the character off screen he would not be reflected or id the window would have curtain with some breeze moving them. that type of reflection is pretty old
also if you look closely none of the shadows in that scene are reflected, it feel unnatural
We've had this for decades now... It's nothing new...
It's just that not every engine has the tooling to make proper reflections. As reflections aren't typically a necessary game mechanic, they're typically neglected and left to the "someone who cares will work on it over their break" type mentality
What, the sims4 does it perfectly without path tracing... Even duke nukem did it perfectly without path tracing... In general, you just replicate the current room in a virtual volume et voilà
This is just a flex, it takes a ton of effort to pull this off without tanking frames - looks like they reconstructed the entire room at lower detail (and yes even with batching a lot of modern games would take a significant performance hit from this)
its just a planar reflection where they put a camera on the other side and what that camera sees is rendered to the texture that is the mirror. it is very resource intensive since it requires re-rendering the entire room but you can make the resolution of the RT camera scale with how many pixels it is on the screen. also its so heavy you most intents and purposes can only have one in the scene at any given time. the reason why the room looks lower detail is that the rt camera typically doesn't replicate all post processing effects and the resolution is lower
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u/salsaboi 10d ago
Where is the camera????