[HN Gopher] 4D Doom
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       4D Doom
        
       Author : chronolitus
       Score  : 277 points
       Date   : 2026-03-27 22:19 UTC (5 days ago)
        
 (HTM) web link (github.com)
 (TXT) w3m dump (github.com)
        
       | superxpro12 wrote:
       | Ok... he was right. It broke my brain.
        
       | scordata wrote:
       | This is an awesome experience. Very useful tool to get exposure
       | to thinking in "higher" dimensions!
        
       | knolan wrote:
       | I found 4D Golf a great game to explore higher dimensional space.
        
         | noman-land wrote:
         | Got a link?
        
           | AStrangeMorrow wrote:
           | I imagine they are taking about 4D golf by CodeParade, as
           | seen here: https://youtu.be/y53UNskR-zU?si=iUfCkxYqkACx955t
           | 
           | Steam link:
           | https://store.steampowered.com/app/2147950/4D_Golf
           | 
           | The person goes over quite a few technical details on their
           | Youtube, though they talk about a bunch of other coding
           | experiments too.
        
             | danbruc wrote:
             | Some of the scenes from the video remind me of Manifold
             | Garden [1] - only 3D but a 3-torus [2] and you can change
             | the direction of gravity, i.e. what is up and down. And
             | also visually beautiful.
             | 
             | [1]
             | https://store.steampowered.com/app/473950/Manifold_Garden/
             | 
             | [2] https://en.wikipedia.org/wiki/3-torus
        
             | extraduder_ire wrote:
             | The additional code he wrote to make a 4d game work in the
             | Unity game engine is available on github and MIT licensed:
             | https://github.com/HackerPoet/Engine4D
             | 
             | When I first saw the title, I assumed this game was
             | implemented in the same engine. I believe there are a few
             | already.
        
       | bstsb wrote:
       | this is visually interesting, but crucially it's also actually
       | fun to play.
       | 
       | i managed to kill three enemies before succumbing to my fate
        
       | danbruc wrote:
       | Now waiting since 16 years for the release of Miegakure
       | [1][2][3].
       | 
       | [1] https://en.wikipedia.org/wiki/Miegakure
       | 
       | [2] https://www.youtube.com/watch?v=9yW--eQaA2I
       | 
       | [3] https://xkcd.com/721/
        
         | mrmckizzle wrote:
         | It's still on my steam wishlist.
         | 
         | https://store.steampowered.com/app/355750/Miegakure_Hide__Re...
        
           | danbruc wrote:
           | On mine, too, forgot that link.
        
         | hiccuphippo wrote:
         | Oh yeah. I remember it every couple of years just to go to
         | wikipedia and see it's not been released yet.
        
         | UltraSane wrote:
         | I wish I could stay focused on a project that long.
        
         | moralestapia wrote:
         | The guy is just a troll. I doubt there's an actual game beyond
         | a cool tech demo.
         | 
         | They haven't showed anything for like a decade.
        
       | saberience wrote:
       | That's not 4D
        
         | lanternfish wrote:
         | Why not?
        
         | bsza wrote:
         | Then what is it? I'm seeing 4x5 transform matrices in the code,
         | looks 4D enough to me.
        
         | integralid wrote:
         | That's exactly 4D. Just like "non euclidean"[1], this term is
         | often abused in entertainment to mean something else, but the
         | post here is about the real 4d world rendering.
         | 
         | [1] For this check out zenorogue work btw
        
       | braelyn wrote:
       | that was incredibly cool
        
       | somat wrote:
       | I just watched the associated dev video And if I understand it,
       | what the author is doing is kind of interesting.
       | 
       | The sensor to see a 3d scene is 2d(eye or camera). What is being
       | done here is simulating a 3d sensor(for a 4d world) then we are
       | looking at this 3d sensor using our 2d sensors (eyes). I don't
       | know if this is the common way of rendering these 4d physics
       | simulations. But it is the first I have heard it described this
       | way. It is also why the narrative of the game focuses on eyes,
       | because that is what it is doing.
       | 
       | https://www.youtube.com/watch?v=tKDMcLW9OnI
        
         | gentleman11 wrote:
         | I don't want to be the guy who has to use this level editor
         | (although, in a similar way, doom was 2.5d, and so the level
         | editor could essentially be 2d, so maybe it's not so bad?)
         | 
         | If this is 4d doom, i wonder what 4d quake could be
        
         | UltraSane wrote:
         | Reminds me a bit of a guy who created a functional virtual
         | camera in Blender with lenses and film layers.
         | 
         | https://www.youtube.com/watch?v=YE9rEQAGpLw
        
         | AndrewDucker wrote:
         | Nitpick - your eyes are, in combination, a 3d sensor.
         | Individually they're 2d sensors, but together they can detect
         | three dimensional information.
        
           | dtj1123 wrote:
           | Strictly speaking this doesn't make them a true 3d sensor,
           | but rather a 2d sensor with an accompanying depth-map. In
           | order for them to be true 3d sensors they'd be have to
           | transmit information about both the near and far sides of an
           | object simultaneously, for example.
        
             | _main wrote:
             | Very true, a 4 dimensional being with 3 dimensional eyes
             | would be able to look inside closed boxes, and see every
             | side of every object at once. (just like we can see every
             | part of a 2d scene all at once)
             | 
             | Not merely 2d + depth perspective.
        
               | strogonoff wrote:
               | Arguably, humans are 4-dimensional beings living in a
               | 4-dimensional world--it's just that one of the dimensions
               | is accessible with much fewer degrees of freedom.
               | 
               | (Not unlike how a seemingly 2-dimensional world of a top-
               | down FPS is actually 3-dimensional, you just have to
               | follow way more rules when it comes to moving in the
               | third one.)
        
           | dickiedyce wrote:
           | Hmmm... Agreed that they're mostly 2D sensors, but apart from
           | near-field the post-processing brain can use depth-cues to
           | for us 'see' in 3D. Also, you don't see in 3D unless your
           | head/eyes/target is moving, right?
        
             | AndrewDucker wrote:
             | You definitely get 3D from just having twin perspectives on
             | an object. You get even more when moving your head.
        
       | xnx wrote:
       | Better title: HYPERHELL, 4-Dimensional DOOM-Like
        
         | gerdesj wrote:
         | Is that the geordie version?
        
       | gipp wrote:
       | The problem with these attempts always seems to be that you can
       | _see_ in dimensions 1-3, but never in dimension 4, so any
       | movement or exploration along that axis is always just blind
       | fumbling. The extra dimension is not equivalent to the others
       | 
       | The only answer would seem to be an extra axis of rotation, but
       | (a) doesnt work well with existing input methods, and (b) would
       | be even more of a brain-breaker
        
         | jitl wrote:
         | I think you could approximate a 4d projection onto a 3d
         | display, much like we approximate a 3d projection onto a 2d
         | display. So perhaps one could enjoy a fun and intuitive game of
         | 4d doom if you have an appropriately fancy volumetric display.
         | Pity they're so rare/expensive.
        
           | Nevermark wrote:
           | Exactly. I prefer my 4D games projected into my Vision Pro's
           | surrounding 3D space. Please.
        
           | tenthirtyam wrote:
           | I've commented elsewhere about an 4D maze
           | (https://urticator.net/maze/ - I am not the author) which
           | mimics this by creating two 3D retinas in red/blue
           | stereoscopic mode - when you cross your eyes just right you
           | see a single volumetric 3D retina.
        
         | heyethan wrote:
         | Feels like in 3D you can move continuously and build intuition.
         | 
         | But in 4D there isn't really an equivalent control, so it ends
         | up feeling more like toggling something you don't fully
         | understand.
        
         | martin-t wrote:
         | Could transparency help?
         | 
         | Ordinarily, a 3D scene rendered in 2D only allows you to see a
         | cone from your eye up to the first surface the ray encounters,
         | thus defining the 2D projection which you see.
         | 
         | But you can make the surfaces transparent so the ray continues,
         | and each additional surface adds a bit to the final pixel. This
         | can look like a mess if you stand still but if you wiggle your
         | movement left and right (or any other direction), your brain
         | suddenly manages to process it into the full 3D structure.
         | 
         | Can something like this be done in 4D?
        
           | yetihehe wrote:
           | Something like "wiggle stereoscopy"[1], but for 3d scenes
           | instead of 2d images. Wiggle tesseroscopy?
           | 
           | [1] https://en.wikipedia.org/wiki/Wiggle_stereoscopy
        
         | pasquinelli wrote:
         | no, you do see along the fourth dimension when you're pointing
         | that way. i think you have a deep confusion here actually, but
         | i can't really help because i don't actually understand your
         | confusion. but, for whatever help it will be:
         | 
         | - all the dimensions are treated the same
         | 
         | - you only actually see two dimensions.
         | 
         | (it goes without saying that it's actually me who's confused.)
        
         | chronolitus wrote:
         | You may need more than 1 extra axis of rotations,
         | unfortunately. https://youtu.be/tKDMcLW9OnI?t=309
        
       | keyle wrote:
       | It's cool and all and I typically enjoy lowres renditions...
       | unless, it actually impacts gameplay.
       | 
       | Since the gameplay is so much about 4D, clarity in what you see
       | becomes more important and the extremely low resolution actually
       | impairs the player rather than serve a positive (typically
       | 'leaves more to the imagination').
       | 
       | It wouldn't take much of an effort to double or triple the
       | resolution which I think would help the gameplay.
        
         | adzm wrote:
         | Agreed this is not even 4d Wolfenstein but still a really neat
         | concept
        
         | somat wrote:
         | The reason it is so low res is actually more interesting than
         | simple aesthetic choice. Think about the sensor(or eye) needed
         | to view a 3d scene, it is 2d right. So this is a 3d
         | sensor(voxels) for a simulated 4d camera. and then we are
         | looking at the 3d sensor. (with our 2d sensor(eyes)), it's
         | sensor inception.
         | 
         | So it is as low res as it is because it is a bunch of voxels
         | simulating a 4d camera.
         | 
         | The dev put out an interesting video on the topic.
        
           | __alexs wrote:
           | There have been other 4D video games with actually good
           | performance though.
        
           | Citizen_Lame wrote:
           | They should have used Gaussian Splats, surely this would
           | reduce processing overhead.
        
           | ninju wrote:
           | Here the video (from the bottom of the page)
           | 
           | https://www.youtube.com/watch?v=tKDMcLW9OnI
        
         | fxtentacle wrote:
         | Fully agree. The low-res makes this unnecessarily hard to
         | navigate. Which is a downside if your core gameplay is to teach
         | players to navigate in a challenging environment.
        
         | isomorphic- wrote:
         | The low resolution didn't bother me too much, but the controls
         | made this completely unplayable for me.
        
         | chronolitus wrote:
         | I really appreciate your feedback!
         | 
         | I tried pretty hard to increase the rendering efficiency on
         | consumer GPUs. The biggest issue is that the main view is
         | actually a 96x96x96 grid of "pixels" (or voxels). This makes
         | scaling brutal: going up to 128x128x128 we'd double the total
         | amount of pixels, to around as much as 1920x1080 resolution.
         | Doubling the grid res to 256 would get us 16M voxels, which is
         | about the same as two 4K displays. On top of that simple 4D
         | object meshes scale much worse in terms of tetras than 3D
         | objects do.
         | 
         | A quick solution could be to give the user a few resolution
         | options, so they can bravely test the limits of their hardware.
         | 
         | So I've just modified the engine to allow you to specify a
         | custom resolution in the URL:
         | 
         | https://dugas.ch/hyperhell/levels/the_bargain.html?vox_resol...
         | 
         | (Higher resolutions might break rendering entirely if the accel
         | structure doesn't fit in allowed memory anymore. I was able to
         | push it to 160x160x160 on my machines)
         | 
         | I'll also try to think of other ways to make the rendering more
         | efficient, maybe a BVH instead of my simpler grid-based
         | acceleration structure? My background is not in computer
         | graphics, so others here might have better ideas.
        
       | jitl wrote:
       | I read a novel when I was 14 or so who's premise is all about
       | creatures inhabiting higher-dimensional space called "The Boy Who
       | Reversed Himself" by William Sleator. I loved Sleator's books,
       | they introduced me to really interesting concepts from
       | theoretical physics as a youngun. If you find 4D Doom intriguing,
       | I encourage you to borrow the book from your favorite ebook
       | library, it's a quick fun read (at least, I remember it that
       | way).
        
         | Darmani wrote:
         | Fun fact: William Sleator's brother is the famous computer
         | scientist Danny Sleator, inventor of the splay tree.
        
         | UltraSane wrote:
         | Part of Greg Egan novel Diaspora takes place in a universe with
         | 5 spatial dimensions.
        
           | ConceptJunkie wrote:
           | I'm still trying to wrap my head around the statement in the
           | book (IIRC) that it takes 8 legs to be stable in 5
           | dimensions. I'd assumed it would be 6, but this is a layman's
           | intuition. Maybe I'm remembering it wrong.
           | 
           | Awesome book regardless.
        
           | chronolitus wrote:
           | Loved this book! Part of this project started from wanting to
           | make 4D creatures and train them to walk with RL. One
           | interesting fact I learned is that ants would probably have 8
           | legs in 4D.
           | 
           | Why? Well, apparently ants have 6 legs because this allows
           | tripod-gait, a simple leg movement that always keeps 3 stable
           | points on the ground[1]
           | 
           | In 4D, you'd need 4 points on the ground, hence tetra-pod
           | gait (4+4 legs).
           | 
           | You could of course do with less, I'd guess even as low as
           | 1-2 if you have lots of muscles and good balance.
           | 
           | [1] https://dugas.ch/4d_creatures/tripod_gait.html
        
       | forthac wrote:
       | If you're on firefox, go to about:config and set
       | dom.webgpu.enabled to "true".
        
       | omershapira wrote:
       | Shameless plug: Horizon (Before the name got saturated), a 4D
       | third-person game https://youtu.be/R6qTi3TCM2U
        
       | Brendinooo wrote:
       | His dev log linked from GitHub is really neat. Mind-bending
       | stuff.
        
       | Narishma wrote:
       | Why does it require WebGPU when it looks like something that
       | would run fine in software on a 386?
        
       | amlib wrote:
       | I find it fascinating that it turns into a "descent like" (6dof
       | fps) when using the ability to "peek" the 4th dimension.
        
         | heftig wrote:
         | The perspective shifts so that the up-down direction becomes
         | the hidden dimension. So the ceiling and floor disappear (and
         | you have trouble avoiding lava) and you only see the walls of
         | the space.
        
       | dluan wrote:
       | I feel like now that I'm older, my brain just can't fully
       | understand it say as quickly if I were younger. Makes me wonder
       | if younger more plastic brains can adjust to having to juggle
       | more dimensions than crochety old ones like mine with very rigid
       | 3D grooves baked in. Or brains from other animals.
       | 
       | I guess taken to the logical extreme, what does the brain of
       | someone/thing that's good at playing this (or any game of N
       | dimensions) look like?
        
         | fredrikholm wrote:
         | If you don't mind me asking, how old are you, and how did this
         | progress? I'm in my mid thirties and am noticing some minor
         | deterioration, but I'm writing it off to loss of sleep due to
         | having small kids.
         | 
         | My curiosity is if this is like you suggest, ingrained
         | patterns, or if there is actual slow down with age. I hear
         | different opinions and am finding it difficult to navigate as I
         | deal with my own, albeit mild, aging.
        
           | dluan wrote:
           | Mid 30s, also have kid and sleep loss but not as bad as
           | before.
           | 
           | I actually noticed serious mental decline when I was burned
           | out in my late 20s. There were real physical symptoms like
           | not being able to look at a text editor for more than 2
           | minutes. Post recovery of that, I actually feel like my brain
           | recovered a lot once I started learning languages very
           | seriously (mandarin and japanese), starting a few years ago.
           | Brain feels healthy now but I'm acutely aware of where it's
           | not as sharp as before. Playing around with this felt a
           | little like when my brain is trying to build a new grammar
           | dictionary.
        
         | ConceptJunkie wrote:
         | I feel the opposite. I'm 61 and I feel like I understand ideas
         | more quickly than I ever did before, so much so that I'm
         | surprised at how shallowly I thought about some things in the
         | past.
         | 
         | While there is definitely something to the plasticity of young
         | brains, for example in language acquisition, or the fact that
         | the Fields Medal eligibility ages out at 40, I believe it's not
         | a linear thing and not a one-way thing.
        
       | gloflo wrote:
       | It's not actually Doom, but a Doom- _like_.
        
         | backspace_ wrote:
         | with those low res graphics, I'd say Wolfenstein like
        
       | razorbeamz wrote:
       | The AI generated logo image is a very big put-off.
        
         | chronolitus wrote:
         | I'd definitely prefer a human made one. If you know any artists
         | willing to make a proper version of the cover art, I'd be happy
         | to commission one (paid, of course).
        
       | amelius wrote:
       | At least project it onto a 3D screen.
        
         | chronolitus wrote:
         | Can't wait for the hardware. Only a matter of time until
         | someone makes the first 4D game projected to a 3D hologram.
        
       | dalmo3 wrote:
       | Reminds me of this 4D minecraft clone:
       | 
       | https://youtu.be/u8LMyWcKL_c?si=XZrCdSSSk9PtpNIP
        
       | tenthirtyam wrote:
       | I can't play this online (no webgpu) but from the description and
       | comments here it sounds like the 4D Maze from 2002!
       | 
       | https://urticator.net/maze/
       | 
       | The advantage of this one is that it offers a stereoscopic
       | (red/blue) view of the 3D retina. Not sure if this one does too.
        
         | chronolitus wrote:
         | Thanks for the link, 4D Maze is amazing and I had somehow never
         | seen it.
         | 
         | Also, here's a CPU-based prototype that led to the Hyperhell
         | engine:
         | 
         | https://dugas.ch/4d_creatures/4d_camera.html
        
       | npodbielski wrote:
       | Enabling webGPU on Firefox still does not allow it to run. It
       | worked on Chrome but I feels kinda like it was not worth it.
       | Maybe if you could change resolution to something better. And
       | starting every time from the same room, through some conversation
       | with NPC? Feels like I have better things to do.
        
       | MisterTea wrote:
       | Perhaps Ive been missing out on the 4D gaming revolution but I do
       | not understand what the 4th dimension is here. Feels like I am
       | missing out on a lot of context.
        
         | pasquinelli wrote:
         | it's a fourth spatial dimension. if you imagine a cube, it has
         | width, height, and depth. a 4d cube would have width, height,
         | depth, and zhlerp, which is its size along a fourth spatial
         | dimension. in three dimensions you can go forward and backward,
         | left and right, up and down. in four dimensions you can go
         | forward and backward, left and right, up and down, and zlep and
         | wizz, moving along the fourth spatial dimension.
        
       | DoctorMacArthur wrote:
       | Cant wait to see ZeroMaster speedrun this
        
       | gray_wolf_99 wrote:
       | Its really a cool project, i loved playing doom game in my
       | childhood hood, and i loved this fast paced Action FPP game....
       | plus the retro looks great,
       | 
       | Hey , did any one played "Total over dose"?
        
       | komodo99 wrote:
       | interesting, very cool demo, but its not the 4d that hurts my
       | brain and/or soul, its an FPS with an inverted X mouse axis...
       | its like the backwards bike, sure it can be done, but my wiring
       | isn't rigged for that!
        
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       (page generated 2026-04-01 23:01 UTC)