Coding Adventure: Portals

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  • Опубликовано: 27 май 2024
  • Experimenting with portals, for science.
    The project is available here: github.com/SebLague/Portals/t...
    If you'd like to get early access to new projects, or simply want to support me in creating more videos, please visit / sebastianlague
    Resources I used:
    tomhulton.blogspot.com/2015/08...
    www.terathon.com/lengyel/Lengy...
    www.scratchapixel.com/lessons...
    www.turiyaware.com/a-solution...
    Chapters:
    0:00 Introduction
    0:25 Figuring out the cameras
    1:41 Test world
    3:09 Texture mapping
    4:27 Trying to understand perspective divide
    5:50 Optimization
    6:50 Making a prettier test world
    7:18 Teleportation, at last!
    9:17 Fixing the flickering
    10:00 Slicing
    12:15 Oblique projection
    13:31 Recursive portals
    15:33 Outroduction
    3D Models:
    Plane: www.turbosquid.com/FullPrevie...
    Car: www.turbosquid.com/FullPrevie...
    Music:
    "Twisting", "Lightless Dawn", "Frost Waltz", "Heart of Nowhere", "At Rest", "Spellbound", "In Your Arms", "Rynos Theme", and "The Builder" by Kevin MacLeod (incompetech.com)
    Licensed under Creative Commons: By Attribution 3.0 License
    creativecommons.org/licenses/b...
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Комментарии • 2,2 тыс.

  • @Revv13T
    @Revv13T 4 года назад +4714

    "Filled with grief and rage, I began debugging." - Every game developer ever
    That is such a big mood

    • @inv41id
      @inv41id 4 года назад +185

      *Every -game- developer ever

    • @motbus3
      @motbus3 4 года назад +101

      The question always comes from
      Why it doesn't work ?
      To
      How it possibly have worked?

    • @CodingJedi
      @CodingJedi 4 года назад +7

      motbus i relate to this!

    • @RegahP
      @RegahP 4 года назад +3

      yes this is me

    • @FlippRipp
      @FlippRipp 4 года назад +5

      this is so relatable :)

  • @humter
    @humter 4 года назад +3454

    "The reason for the traveler's unfortunate demise is that this function that detects when an object leaves the portal depends on the internal physics loop which runs on its own fixed timestamp"
    Me, eating unsalted peanuts and has never coded anything: A rookie mistake

    • @SETHthegodofchaos
      @SETHthegodofchaos 4 года назад +12

      @TF Tingle Thanks, but you forgot to fly away, Captain!

    • @snwdn
      @snwdn 4 года назад +142

      This is the level of detail I come to the comments section for.

    • @deneb3525
      @deneb3525 4 года назад +27

      Mann... you have no idea some of the wonky bugs I've had due to those being different loops.

    • @hazeltree7738
      @hazeltree7738 3 года назад +8

      "The reason for the traveler's unfortunate demise is this weird entity called "Dominus Gaul" spawned in and started wreaking havoc on its code"

    • @humter
      @humter 3 года назад +10

      Why did this terrible comment get 1k likes

  • @pythontron8710
    @pythontron8710 4 года назад +1862

    Do you think the guys behind supposedly calm and chill programming channels actual freak out and break shit when they've been stuck on a problem for a long time? Like, he says how he had an issue, so he found an article with the solution, when in reality he tore his hair out searching google for hours until he misclicked on a link that luckily had the solution.

    • @hunterbuns
      @hunterbuns 3 года назад +347

      His voice is far too soothing. I refuse to imagine this possibility.

    • @bravewagster
      @bravewagster 3 года назад +284

      I think the youtuber 'Code Bullet' is a perfect example of this happening

    • @subliminalcastillo2126
      @subliminalcastillo2126 3 года назад +109

      I absolutely do. When you make a video you are editing it & planning out & designing an experience for somebody.
      You can craft that experience to be whatever you want it to be.
      It's just like a cute girl who uploads a new profile picture on her facebook. Do you really think she didn't take 50 pictures and fix her hair, and adjust the angle, and do a million steps to make the final result look as good as possible?

    • @gblawrence034
      @gblawrence034 3 года назад +36

      I get disproportionately mad when I can’t figure something out

    • @thedude4039
      @thedude4039 3 года назад +51

      @@gblawrence034 I've been kind of numbed to the frustration by now. When I can't figure something out I don't get angry, I instead get lazy and stop working on it. Then I come back to it later on again and again when I feel more motivated.

  • @rvke3763
    @rvke3763 4 года назад +1678

    "The code for this pretty simple..."
    Me: Sees Vector4

    • @MichaelPohoreski
      @MichaelPohoreski 4 года назад +141

      Vector4 is just 4 independent numbers.
      It's how those 4 numbers _interact_ with another 4 numbers that makes it complicated. ;-)

    • @mateineli209
      @mateineli209 3 года назад +1

      Wach @brackes

    • @bogiesmigforl1
      @bogiesmigforl1 3 года назад +5

      @@mateineli209 what

    • @thatboredinternetwanderer140
      @thatboredinternetwanderer140 3 года назад +9

      @@bogiesmigforl1 He means @Brackeys i think

    • @mateineli209
      @mateineli209 3 года назад +1

      @@thatboredinternetwanderer140 i mean he

  • @alexjoe3267
    @alexjoe3267 4 года назад +4895

    "The code for this is actually quite simple."
    Proceeds to execute rocket science.

    • @genetichell
      @genetichell 4 года назад +97

      Well that would certainly explain the KSP music in the background :P

    • @Mafia200100
      @Mafia200100 4 года назад +81

      Rocket science is also pretty simple.
      It's the rocket *engineering* that's the difficult part.

    • @alessiobenvenuto5159
      @alessiobenvenuto5159 4 года назад +16

      @@Mafia200100 modestly, I'm a KSP player.

    • @AndrewFullerton
      @AndrewFullerton 4 года назад +5

      Hoo-ray

    • @Peak_Stone
      @Peak_Stone 4 года назад +27

      ​@@Mafia200100 Rocket Engineering is quite simple, it's the maths thats complicated.

  • @krasnoiark
    @krasnoiark 4 года назад +2946

    This just proved me how insane valve was when they made portal

    • @ducky8075
      @ducky8075 4 года назад +399

      Funny enough, valve’s implementation was completely different!

    • @Hoichael
      @Hoichael 4 года назад +509

      *how insane a bunch of college students were when they made portal ;)

    • @localatticus4748
      @localatticus4748 4 года назад +71

      @@ducky8075 It was actually extremely similar.

    • @randomcatdude
      @randomcatdude 4 года назад +225

      @@localatticus4748 The difference is that Valve used stencil buffers for their portals, instead of render targets.

    • @KuraIthys
      @KuraIthys 4 года назад +156

      Portal is nowhere near the first game engine to use this technique.
      But most of the early ones used this to increase performance (yeah, ironic, right? But with the right setup it does the trick).
      I don't know if there are earlier examples, but the most prominent game using this technique purely for performance reasons is the Descent series. (came out the same year as Doom, yet could do a fully 3d world on a 386)
      Another prominent example that used it for a mixture of performance and special effects is the Build engine. (Duke Nukem 3D's engine)
      Given that the Build engine is not a proper 3d engine and has a lot of similar limitations to DOOM, the portal based rendering system is one of the reasons why you can nonetheless do things that are impossible for Doom, such as having a building with multiple levels.
      The reason this works is because the windows/doors/whatever into each floor are actually portals that take you to a different portion of what is otherwise a 2d map.
      An interesting limitation of the Build engine caused by it's 2d nature but use of portals is while you can have a multi-storey building with access to different levels, and windows that show all the levels at once...
      You cannot have two openings directly above one another.
      All openings to different locations have to be horizontally seperated.
      This is because while the portals can be at different heights on a wall that gives the impression of there being multiple levels to a building, in reality the entire world is 2d, and a wall section can only have a single portal on it.
      So while two portals can be at different apparent heights and be horizontally adjacent, you cannot put a portal on top of another portal...
      It's weird, and fascinating looking at the strange limitations of older games...

  • @flitey
    @flitey 4 года назад +525

    I love coding videos for this reason:
    "I also got sidetracked and started drawing clouds."
    "No time. 7 min in. gotta get to it."

  • @whoisj
    @whoisj 3 года назад +799

    When ever I get frustrated at work (working on the software engines that run artificial intelligence), I come and listen to Sebastian. He's so calm about coding and debugging that I nominate him the "Bob Ross of Software Development" 😁 Combine that with his self-deprecating, deadpan humor and it's a pure delight watching (and re-watching) these videos.

    • @gdb5549
      @gdb5549 2 года назад +10

      sebastian ross

    • @rootabeta9015
      @rootabeta9015 2 года назад +5

      I second the nomination

    • @WinterNox
      @WinterNox 2 года назад +1

      Good bro

    • @Enderia2
      @Enderia2 Год назад +3

      @@rootabeta9015 I third the nomination

    • @Brahvim
      @Brahvim 10 месяцев назад +1

      @@Enderia2 May I fourth?

  • @quaternaryyy
    @quaternaryyy 4 года назад +1420

    Portal (the video game) uses a hybrid approach to recursive portals: the first few iterations are drawn using a recursive camera technique (like in your portals), but the initial texture is a scaled and distorted version of the previous frame. The effect looks pretty good, but there are some cases where it breaks down, like when the portals are not at 180 degrees to each other, if they're too close, or if they're drawn at a sharp angle on-screen. It definitely beats having a black texture, though, and looks passable even with only 2 or 3 "real" levels of recursion. It really helps sell the look on low graphics settings, and it's very important in Portal 2's co-op where having player 1's portals + player 2's portals + water reflections + shadows + splitscreen/partnerview means there can be tons and tons of rendering passes.
    Objects partway through portals use a "clone" approach (also like in your portals). The clone has limited support for physics, and tries to transfer forces applied to it to the real object on the other side of the portal. It doesn't work very well and looks "spongy" if you try to break it, but it at least prevents you from making things intersect and dropping things inside your own hitbox, and works best with simple cubes which is what most of Portal's objects are anyways. There are some physics optimizations: objects close to portals don't collide with anything far from portals, objects far from portals don't collide with any clones, and so on.
    Oh, and to make the portals appear oval-shaped, it just draws an oval to the stencil buffer and hides the seam with the rim texture and particle system. As far as physics are concerned, the portals are rectangular.
    (My source for this is a great talk given at some school by Valve graphics and physics programmers, but I can't seem to find it anymore!)

    • @SebastianLague
      @SebastianLague  4 года назад +212

      That's really interesting thanks! I was wondering what their approach was. Will have to look about for that talk.

    • @clonkex
      @clonkex 4 года назад +137

      ​@@SebastianLague That talk is here if you're wondering: ruclips.net/video/ivyseNMVt-4/видео.html&t=3642 And check out my other comment for more info: ruclips.net/video/cWpFZbjtSQg/видео.html&lc=UgwV7y6dKJgF-7S44fJ4AaABAg
      EDIT: Hmm, seems you can't click the comment link. I think if you right-click and open in new tab it will work, but you might have to pause the video and scroll down.

    • @SebastianLague
      @SebastianLague  4 года назад +116

      @@clonkex Awesome, thanks!

    • @LegoEddy
      @LegoEddy 4 года назад +39

      This explains how the math challenges actually influenced the game design. That's stunning

    • @TheBcoolGuy
      @TheBcoolGuy 4 года назад +47

      @@SebastianLague Another idea is to lower the resolution of the cameras with each iteration into it.

  • @bryantmontgomery2736
    @bryantmontgomery2736 4 года назад +1481

    "The maths went way over my head"
    Me: nods along

    • @kingpanguan
      @kingpanguan 4 года назад +12

      10 hours?

    • @guyingrey1072
      @guyingrey1072 4 года назад +4

      Yea how 10 hours ago? Early access of some sort?

    • @AkshayKumarX
      @AkshayKumarX 4 года назад +9

      @@BigBean916 Patreon users get early access to new video releases I think.

    • @me.unpredictable280
      @me.unpredictable280 4 года назад

      Your comment is 11 hours in past somehow.

    • @turdle2767
      @turdle2767 4 года назад +1

      @@me.unpredictable280 all comments are from the past

  • @trolmaso
    @trolmaso 3 года назад +445

    Sebastian: *coding 4D planes*
    Me: *getting errors coding Hello World*

    • @angelcore1669
      @angelcore1669 3 года назад +9

      Gotta start from somewhere

    • @thijewissema6412
      @thijewissema6412 3 года назад +12

      lemme guess, ; ?

    • @thatboredinternetwanderer140
      @thatboredinternetwanderer140 3 года назад +1

      @@thijewissema6412 why is the semicolon necessary

    • @samfriend3675
      @samfriend3675 3 года назад +14

      @@thatboredinternetwanderer140 It acts as an "End Line of Code" command to the compiler in most languages. Although a new paragraph could be used (as it is in python), there are some situations where you want something the compiler recognises as a new line without a physical new line (For loops do this in some languages), and other situations where a physical new line splitting code may be problematic (eg. small screens, or zooming in for a presentation, or just splitting a long line of code into the things it does for readability).
      The semicolon is ANNOYING, I agree, but having something there to detect the end of the line can allow for formatting that isn't possible without it. Sure, as an amateur, its annoying, but its worth it for the proffessionals doing massive coding tasks beyond either of our comprehension.

    • @thatboredinternetwanderer140
      @thatboredinternetwanderer140 3 года назад

      @@samfriend3675 yeah i know

  • @WannabeCanadianDev
    @WannabeCanadianDev 3 года назад +81

    "I got a bit side tracked by making some low poly clouds"
    There is something lowkey hilarious about everything you say Seb.

  • @EDSCello
    @EDSCello 4 года назад +1208

    I hate that you made this video after I spent the last four weeks looking how to do it.
    Also love you thanks.

    • @mmyesrice2522
      @mmyesrice2522 4 года назад +15

      oh dude i know the feeling

    • @BlakeGillman
      @BlakeGillman 4 года назад +16

      I felt similarly about his implementation of natural selection. Not that I was looking how to do it, but it was something I was planning on simulating myself and now doesn't seem worthwhile since someone else has done it in such a... quality way. I like to feel original or at the very least that I've improved on the system from which I derived my inspiration.

    • @r033cx
      @r033cx 4 года назад +3

      I know right... My implementation looks very bad after I've seen this

    • @thevitulus
      @thevitulus 4 года назад +5

      @@BlakeGillman Well maybe you could find a way to do something even more interesting with it as a base!

    • @luna010
      @luna010 4 года назад +1

      @Marcello Menezes
      There’s also this> ruclips.net/video/_SmPR5mvH7w/видео.html
      Video

  • @iamarugin
    @iamarugin 4 года назад +2396

    "The maths went way over my head"
    Me, seeing simple vector multiplication.

    • @icxonrus
      @icxonrus 4 года назад +33

      Can relate.

    • @Samudbhava
      @Samudbhava 4 года назад +1

      Relatable

    • @clonkex
      @clonkex 4 года назад +49

      @@isaacgejames They're pretty simple actually, and once you understand what they really mean you can do some nice stuff with them. In essence they're literally just a set of 3 numbers. You could use the Vector3 class to store whatever numbers you want. Usually they are used to represent a direction, but also commonly used to represent a position. A direction is really just a position _relative_ to another position.

    • @clonkex
      @clonkex 4 года назад +20

      @@isaacgejames Yeah so to create a direction that points forwards, you'd use 0, 0, 1. That's 0 units on X, 0 units on Y and 1 unit on Z, which means the final location is 1 unit forwards. 0, 0, 2 would also point forwards, as would 0, 0, 6000. The way to picture this is just imagine a point at the centre (so, 0, 0, 0) and a point at your vector (such as 0, 1, 0) and then imagine an arrow pointing from the centre to the vector point.

    • @SETHthegodofchaos
      @SETHthegodofchaos 4 года назад +8

      @@isaacgejames The Godot Game Engine has a nice documentation on how vectors work and what you can do with them. Have a look here:
      docs.godotengine.org/en/3.2/tutorials/math/vector_math.html

  • @RagdollGaming_
    @RagdollGaming_ 3 года назад +329

    3:30 It took me a few moments to realize that this was, in fact, not editing, but something you programmed into the game for the sake of visualization
    Super well done, I learned a lot!

    • @IrchaMan
      @IrchaMan 3 года назад +8

      Yeah, but he allready coded it, no biggie to display the maths on the screen. Cool visualization anyways :)

    • @SanyaBane
      @SanyaBane 2 года назад +1

      Indeed, it's extremely helpful

    • @ShatabdaRoy115
      @ShatabdaRoy115 2 года назад

      He is a genius

    • @bluegreenmagenta
      @bluegreenmagenta Год назад

      It's such a cool edit trick

  • @Ugamaflop
    @Ugamaflop 4 года назад +94

    I know you have a Coding Adventure: Clouds, but could you post a tutorial on how you did those Low Poly ones? They're beautiful

    • @massimookissed1023
      @massimookissed1023 3 года назад +12

      Just my guess:
      The centre of a cloud moves across a map of perlin noise.
      The (noise value [above some threshold]) x (proximity to centre of cloud) defines the radii of either:
      low poly spheres unioned together,
      or: spheres unioned together with low poly marching cubes algo to create the cloud's surface.

  • @Danidev
    @Danidev 4 года назад +2186

    Whoooaaa that was amazing :o

  • @PKMartin
    @PKMartin 4 года назад +251

    "It's seven minutes into the video and you still can't walk through the portals"
    "Overcome with grief and rage, I began debugging"
    "I'll cue up some old-timey music so we can sit back and watch the result"
    This is not only one of your most educational videos, but one of your funniest to date as well. Coding Adventure is my favourite dev series on RUclips

  • @Teamotei1
    @Teamotei1 4 года назад +21

    Now you're thinking with portals.

    • @Silas_MN
      @Silas_MN 3 года назад +1

      Took me longer than I expected to find this comment, but at least *somebody* posted it

  • @wesleymays1931
    @wesleymays1931 4 года назад +132

    I honestly want you to make a library out of this, so nobody has to repeat this painful endeavor.

    • @accountdeleted3706
      @accountdeleted3706 Год назад +3

      That would be really cool

    • @Brahvim
      @Brahvim 10 месяцев назад

      CodyCantEatThis used this code, too! So...

  • @mmyesrice2522
    @mmyesrice2522 4 года назад +436

    I personally think foggy portals is a great solution to the recursion problem! Could also add a blur filter at each subsequent iteration to make the end of the recursion less noticeable. Beautiful work anyhow!

    • @pixeldust8362
      @pixeldust8362 4 года назад +72

      the portal games detect 3+ portals and just start repeating the already rendered textures, as an idea

    • @mmyesrice2522
      @mmyesrice2522 4 года назад +2

      ​@@pixeldust8362 smart!

    • @romajimamulo
      @romajimamulo 4 года назад +4

      It could also be used to get away with rendering the back portals at a lower resolution

    • @romajimamulo
      @romajimamulo 4 года назад +1

      @@pixeldust8362 portal 1 has a setting for how many to do, that goes up to nine. How does that interact with this?

    • @635574
      @635574 4 года назад +1

      @@romajimamulo isnt that just the cutoff for when its a texture of last frame?

  • @darcksage1
    @darcksage1 4 года назад +76

    7:10 those are some nice clouds

  • @yrussq
    @yrussq 3 года назад +19

    "But we have no time for this. We are 7 minutes in the video and still can't walk through portals" (c)
    I love this man! Each and every tutorial is full of useful stuff, clear explanations and don't waste the viewers' time. I wish all the RUclips tutorials were so awesome and respectful about the time!

  • @SiegeTales
    @SiegeTales 4 года назад +505

    god bless the internet

    • @unregulardude
      @unregulardude 3 года назад +1

      Siege Tales! Wow you have great taste in videos!

    • @octothedog
      @octothedog 3 года назад

      Never thought I'd be seeing you here! Love your videos dude or dudette!

    • @jakematchett8160
      @jakematchett8160 3 года назад

      Siege Tales you're literally in the most unexpected places I swear dude

    • @casualinklingcrusher3005
      @casualinklingcrusher3005 3 года назад

      Ikr

    • @NepNepYT
      @NepNepYT 3 года назад

      Ew

  • @justinflowers9380
    @justinflowers9380 4 года назад +231

    Using a 3D object on a 2D Screen, to project a 3D object onto a smaller 2D Screen, which is apart of the Original 3D object projected on the 2D Screen, projecting a 2D object that projects a 3D Looking object?
    *Makes sense to me.*

    • @xGOKOPx
      @xGOKOPx 4 года назад +8

      All that "rendered" on your 2D eyesight plane

    • @blinded6502
      @blinded6502 4 года назад +17

      ​@@xGOKOPx Then it all is used to light up pixels on a monitor, which emits photons, that then pass through the eye lens, converge on your retina, creating smaller inversed image. Then photons pass through the membrane of photoreceptive cone and rod cells and get absorbed by pigment, making it oscillate. Due to that oscillation pigment falls apart, which triggers chain of chemical reaction, which changes salt concentrations inside the cell. That triggers neurons, which encode image to a smaller format, where edges are compressed. Then that signal is transmitted via repeated sequence of releasing chemicals and conducting electricity, until it finally reaches the image processing part of the brain, which was trained to recognize visual patterns in order to feed information to other brain neurons.

    • @doeverything2615
      @doeverything2615 4 года назад +2

      Pretty sure he mentioned somewhere in the video he made a 4d plane

    • @elizabethdespair
      @elizabethdespair 4 года назад

      @@doeverything2615 literally

  • @ArnoldsKtm
    @ArnoldsKtm 4 года назад +322

    Insane work put into this. Writing shaders scare me but this was so great.

    • @r033cx
      @r033cx 4 года назад +5

      Shaders are not that complicated actually, maybe just a little bit confusing at first
      Shader cutting out part of the camera view like in the video is very clever, but also very easy to do

    • @Labiote
      @Labiote 4 года назад +2

      ​@@r033cx I'm really interested by learning stuff about shaders. Where should I start digging ?

    • @squeakybunny2776
      @squeakybunny2776 4 года назад +1

      Shades can be done with nodes right? Maybe start there.
      Maybe someone with more expertise can highlight the benefits of using nodes compared to writing code

    • @pineappleparty1624
      @pineappleparty1624 4 года назад +1

      @@Labiote Here is a course from a game dev professor. I already have it purchased so I can't tell what the current price is. These go on sale for 10 bucks all the time. I have done her other courses and they are amazingly programming rich. www.udemy.com/course/unity-shaders/

  • @grantsutton7295
    @grantsutton7295 4 года назад +9

    I understand maybe 6% of each coding adventure video and just keep coming back to remind myself how much more I still have to learn

  • @Aherea
    @Aherea 2 года назад +9

    "While I've been writing this, the car's been struggling tremendously to drive over a little rock. 10/10 for effort, though."
    This kind of thing is what makes your channel fantastic instead of merely great. :)

  • @jupitersky
    @jupitersky 4 года назад +175

    The fading to black is how mirrors work IRL, so that makes a lot of sense.
    Edit, for all of you saying "but it's not a mirror."
    The point is to make be more sensible than "oh it just cuts off at a certain distance." It doesn't even have to fade to black across so many iterations, maybe just the last four fade to black.

    • @seekyunbounded9273
      @seekyunbounded9273 4 года назад +42

      well mirrors don't perfectly reflect the light so they eat up the energy, proper portal wouldn't eat it up so it wouldn't lose any light

    • @nimphilia
      @nimphilia 4 года назад +11

      fading to greenish black makes more sense

    • @muuubiee
      @muuubiee 4 года назад +7

      @@nimphilia Because of red shifting?

    • @lars0me
      @lars0me 4 года назад +17

      @@muuubiee Because of what Seeky Unbounded said. Mirrors are not perfectly reflective, so with every reflection they absorb a tiny bit of light matching their own true color. Which for most happens to be green. (Look through a thick piece of glass at its side)
      For portals you could probably either do a similar thing in any given color (e.g. based on player team) or simulate the color of air/fog.

    • @DanielEidi
      @DanielEidi 4 года назад +4

      It's not a mirror though.

  • @MTandi
    @MTandi 4 года назад +199

    You could add some *magical* distortion instead of the fading out effect .
    Like water distortion or blur that starts from the second portal and scales up.

    • @milanstevic8424
      @milanstevic8424 4 года назад +7

      that's not an instant solution. you need to come up with a shader that will sufficiently distort image after N iterations. that might be harder than it sounds, and also might turn out to be messy and/or not cheap. besides, how does the fully distorted image look, is it white noise, is it pink noise, is it black or some other pure color? whatever it is, it doesn't sound that much better. if it's about eye-candy, you could practically add a slight distortion effect only to the second iteration and keep the remainder of the solution intact, and arrive at what you proposed, but arguably much cheaper, and in a controlled manner.

    • @Benwager12
      @Benwager12 4 года назад +29

      @@milanstevic8424 What MTandi proposed was an idea, it sounds like you're trying to put him down for suggesting a possibility. The kinks can be worked out later.

    • @avananana
      @avananana 4 года назад +14

      @@milanstevic8424 You're talking as if the portal itself was easy to make. It's fucking obviously the distortion effect would be harder to make than it sounds. Easier said than done, as every god damn coding project goes.

    • @FPRobber
      @FPRobber 4 года назад +10

      I think the easiest solution would be to just reuse the view from the second to last portal. It's not completely accurate, but probably good enough given it's super small.

    • @milanstevic8424
      @milanstevic8424 4 года назад +2

      @Ben Wager and @Avana
      I don't get you two.
      I have argued my position => i.e. I've offered an educated argument against such an idea, and also offered an alternative solution to introduce a visual effect of what he called a *magical* distortion.
      If you want to be emotional about it, go watch Twilight.

  • @shenshaw5345
    @shenshaw5345 Год назад +15

    Guys If u want to use this in HDRP or URP its really easy. I got working portals in both.
    In PortalTravelers change line 56 from foreach (var mat in renderer.materials) to foreach (var mat in renderer.sharedMaterials).
    In MainCamera change line 11 from void OnPreCull to void LateUpdate
    for URP enable the Post Processing checkbox under each portal camera. (Main camera doesn't matter)
    for HDPR I did not change anything.
    * Found this solution on Github but just wanted to share here.
    *Using 2021.3.15

    • @simon.in.motion
      @simon.in.motion Год назад +1

      Thanks a lot man ! I was going to quit haha

    • @hubagarai3002
      @hubagarai3002 Год назад +1

      Brother, you saved me! I spend 2 hour to find out what is wrong with it. I read waay too many doc, and now I know some new method for SRP, HDRP and LWRP... I just wanted to use URP 😭

  • @nitroflap
    @nitroflap 3 года назад +41

    Valve: our Portal series was really hard to develop and unique!
    Sebastian: hold my adventure.

    • @Enderia2
      @Enderia2 Год назад +7

      Valve, actually: we hired like 10/20 college students and they made portal so we threw 40 people at portal 2

  • @Madderthanjoker
    @Madderthanjoker 4 года назад +155

    "Alleviate the GPUs suffering...."
    Chuck that bad boy into even more complex math solutions.

    • @IrchaMan
      @IrchaMan 3 года назад +3

      Yeah, alleviate the gpu so the cpu can suffer xD To be fair, that's what the cpu is for anyways :)

  • @anselme198
    @anselme198 4 года назад +484

    Still not perfect, the hardest part remains : lighting. Let light go through portals

    • @alejolab
      @alejolab 4 года назад +65

      As the video progressed I assumed he would get to this eventually. Those are great portals anyway

    • @RoboDK7
      @RoboDK7 4 года назад +38

      I think that could just be done with having cloned lights for if the light is close enough. I dont know if there is a way to check for that but would propally give a really good effect

    • @MateHomolya
      @MateHomolya 4 года назад +7

      yeah I would love to see an episode on lighting and physics through portals!

    • @alejolab
      @alejolab 4 года назад +38

      @@RoboDK7 Simply cloning lights wouldn't work. You still need to block the light so only the light that goes through the portal is rendered. One way would be to have an invisible object around the portal that can block the light and layers or similar to assign lights to specific layers, but then if the portals are close to each other you could still see double lights in some places. It's very tricky.
      But probably Sebastian would find some transformation matrix or whatever that saves the day 😂

    • @rv8891
      @rv8891 4 года назад +12

      @@alejolab That sounds like a such a nightmare for dynamic portal. You might have to construct some in-between space that contains the geometry and lightsources as clones, and merge the results somehow.
      But I'm very happy to be proven wrong on that, especially with working code examples :P

  • @Magnogen
    @Magnogen 3 года назад +136

    I wonder how he's going to add this concept to his solar system project...
    Wait. WORMHOLES!

    • @redaipo
      @redaipo Год назад

      quantum tunnels

  • @NikHem343
    @NikHem343 Год назад +1

    There „camera box“ absolutely blew my mind

  • @sapumalkalutota
    @sapumalkalutota 4 года назад +186

    This was a triumph!
    I'm making a note here:
    Huge success!

    • @EdgePR0
      @EdgePR0 4 года назад +29

      It's hard to overstate my satisfaction!

    • @You-qe6qb
      @You-qe6qb 4 года назад +27

      Aperture Science:

    • @ShaunDreclin
      @ShaunDreclin 4 года назад +25

      We do what we must, because we can.

    • @KrzysztofGnutek
      @KrzysztofGnutek 4 года назад +22

      Except the ones who are dead.

    • @renfrew24ify
      @renfrew24ify 4 года назад +23

      But there's no sense crying over every mistake

  • @blackasthesky
    @blackasthesky 4 года назад +20

    For the recursion problem:
    The guys from Valve "solved" it by just re-using the rendered texture from a certain point on, e.g. from a depth of 3. They then distort them to make them warp out of frame. This does not look very realistic, but People won't see it if you start re-use at a depth of 5 or so... Depends on the size of the portals and the details in the scene of course.

  • @shadowflame45
    @shadowflame45 Год назад +6

    im just making this a comment for whatever fix i find
    shader fix
    in the properties section below the
    _InactiveColour ("Inactive Colour", Color) = (1, 1, 1, 1)
    just paste in:
    _MainTex("Base (RGB)", 2D) = "white" { }
    teleport rotation fix
    if you walk through a portal and your rotation snaps, thats normal, but likely not wanted.
    if you copied the project directly from the repo, you shouldn't have this problem, but here's the solution:
    in your movement script, switch the inheritance to PortalTraveller
    then paste this function somewhere
    public override void Teleport(Transform fromPortal, Transform toPortal, Vector3 pos, Quaternion rot) {
    transform.position = pos;
    Vector3 eulerRot = rot.eulerAngles;
    float delta = Mathf.DeltaAngle(rotationY, eulerRot.y);
    rotationY += delta;
    transform.eulerAngles = Vector3.up * rotationY;
    Physics.SyncTransforms();
    }
    if you paste this and do nothing with it, it likely wont work.
    this is because i might use a different variable name than you
    the rotationY is probably going to be the only different variable, this variable is for the camera's Mouse X:
    rotationY += Input.GetAxisRaw("Mouse X") * sensitivity * Time.deltaTime;
    also, the Physics.SyncTransforms() fixes another problem, which was if you used a character controller, you wouldn't teleport
    :D

  • @amir_hossainoroujlou3001
    @amir_hossainoroujlou3001 2 года назад +12

    this guy is a legend in mathematics and programming, super inspiring for everyone such as me

  • @chakflying1
    @chakflying1 4 года назад +69

    Amazing! When I was doing my course project on game development, I wanted to implement portals. I researched for many weeks, arriving to the same conclusion as you for the camera movements, clone on teleport and the screen texture cutout, but you went above and beyond in implementing the portal within portals rendering, and the trick of making the portal surface a cube without back-face culling absolutely blew my mind! Thank you for all this great education.

    • @milanstevic8424
      @milanstevic8424 4 года назад +3

      it is awesome indeed. rich in IQ and well investigated so that we can all have a quality discussion and at least some concrete troubleshooting experience from a dev perspective. Seb's channel doesn't hold your hand, but instead grabs you up by the collar.

  • @Plafintarr
    @Plafintarr 4 года назад +8

    That old automobile casually rolling off the cliff with the classy relaxing oldtimey music in the background... Lmao

  • @dr.unventor
    @dr.unventor 3 года назад +22

    When you think when he explains stuff with animations and you see that he actually coded it to explain

  • @subject2749
    @subject2749 Год назад +1

    The music for this video is set up like a horror movie, love it.

  • @Emeralve
    @Emeralve 4 года назад +74

    The editing on this video is phenomenal
    absolutely enjoyed everysingle part of this video

  • @yourcommander3412
    @yourcommander3412 4 года назад +18

    I lost my mind at the model cutoff , you go way beyond ! Cheers !

  • @realbrickbread
    @realbrickbread Год назад +1

    1:59 "void awake()" sounds like you're sommoning an eldritch horror

  • @champagnesupernova1839
    @champagnesupernova1839 2 года назад +5

    Aperture Science's computing department is really going above and beyond

  • @MrBricks148
    @MrBricks148 4 года назад +70

    Almost thought I had KSP open in the background >___>

    • @MrBricks148
      @MrBricks148 4 года назад

      Also, relative velocity with portals could be fun.

    • @LinOGGaming
      @LinOGGaming 4 года назад +1

      same lol

    • @PKMartin
      @PKMartin 4 года назад +3

      I was about to ask what the music at 6:30 was, I knew I recognised it from a game but couldn't place which one.

    • @gernyiblazs
      @gernyiblazs 4 года назад +1

      I actually have a modded to hell version running. I don"t close it just disable the sound so I can watch videos while eating because it takes like 5 min to start. I was really confused how it re enabled the sound by itself :D

  • @eryberto87
    @eryberto87 4 года назад +49

    My reaction when i see a new coding adventure: *screams*, "Wow another one!"

    • @gen157
      @gen157 4 года назад +3

      I love the approach he takes to learn some of these things, going so far to demonstrate using an entire scrap of a scene to show us, the viewers, a better idea before actually showing it implemented. It works great to learn from and it works great to teach from. Always looking forward to the next adventure from him. It's great.

  • @BinaryVectorJr
    @BinaryVectorJr 4 года назад +10

    Videos like these are one of the reasons why I constantly keep falling in love with game development. I just discovered your channel, and within 2 minutes, I was subbed. What a well done video!

  • @sunilkoppuridoge1638
    @sunilkoppuridoge1638 3 года назад +1

    Thanks for letting CodyCantEatThis make portal 3.

  • @artemgusev2826
    @artemgusev2826 4 года назад +12

    6:20 KSP music then you acheve space)))))) So many memories.......

  • @mogaming163
    @mogaming163 4 года назад +32

    We are blessed with this video

  • @Skyteks
    @Skyteks 3 года назад +3

    15:47 GLaDOS voice from somewhere in the Room: "Now you're thinking with portals"

  • @user-hl8tw9kk6e
    @user-hl8tw9kk6e Месяц назад +1

    Hitboxes in this simulation are broken. Only graphics of object slices, but collider doesn't slice when it goes through portal, so we can interact with invisible part of the car, and can't interact with clone, when it is in portal. Look at colliders in 11:22

  • @kairon156
    @kairon156 4 года назад +6

    While I'm only a simple gamer I really enjoy how you show what goes on behind a game mechanic.
    The most coding I've ever done was visual coding with the Unreal Engine. Following tutorials and messing around with what I learned.

  • @NexysStormcloud
    @NexysStormcloud 4 года назад +208

    I wonder how you would solve the problem of the possibility of AI seeing through the portal. Nevertheless, thanks for the great video!

    • @GermanTopGameTV
      @GermanTopGameTV 4 года назад +7

      Just get your AI to interprete what is seen on screen. a simple solution to this is to draw the world in a simplified way for the AI.
      Example: First person shooter
      The AI sees pathing decals as a simple green spots that fade away when they reach them, enemies as red boxes (shoot here when visible after x amount of time to simulate reaction time), allies as blue (do not shoot) and the environment as yellow. This can be rendered at a really low resolution, but using the exact same setup as the world render uses. The AI then just needs to be trained (by you or by some learning algorithm, depending on your prefered behavior) to use the camera output to perform desirable actions. Something along the lines of "If green can be seen, move towards green", "if red can be seen, stop and fire your weapon towards red", "if blue can be seen, follow blue" and "else move randomly". This would give you a zomby like AI that can use portals, runs around in groups and, whenever it sees a checkpoint, moves towards it - so it could patrol an area or follow a certain course through a level, but also adapt whenever a portal happens to open infront of them to rethink it's movement and actions.

    • @TMtheScratcher
      @TMtheScratcher 4 года назад +1

      @@GermanTopGameTV Much simpler without training: Just loop trough the pixels of the image, the AI would receive (with simplified environment) and just check whether the color is seen on it or not. Then do desired action based on these and other factores. Aiming at a specific pixel is also easy calculatable. Or make it move towards until the target color is at the center of the AI's screen, to simulate movement and reaction time

    • @Pinkhair3d
      @Pinkhair3d 4 года назад +6

      A lot depends on how your AI sees in the first place- if it is raycasting, you can do the same sort of matrix transformation to deflect the rays they cast out when those rays hit a portal. If you are using a pathfinding based solution, you'd want to link up the portals' nodes on the pathfinding graph.

    • @Chris_t0
      @Chris_t0 4 года назад +1

      AI site wouldnt be very hard in comparison to all he did for the player to be able to see. The math is simple the hard part is shaders and artifacts etc..

    • @anonanon3066
      @anonanon3066 4 года назад +1

      @@GermanTopGameTVnah lol. Even if you could manage to train an NN (which you would absolutely need) to actually do this well, you would have like .4 fps

  • @BlazeMakesGames
    @BlazeMakesGames 3 месяца назад

    I've been having some ideas of how to use portals in a horror context lately but I wasn't sure how much effort I wanted to go through for a relatively minor effect, but this project will help me a ton in figuring it out

  • @shugabrush3671
    @shugabrush3671 2 года назад +1

    This took a lot of troubleshooting for me to work out, but after a several attempts and a lot of troubleshooting I got this to work better than I had ever had portals working before.

  • @pineappleanimates
    @pineappleanimates 4 года назад +8

    11:10 imagine a game that's only shadows
    like that would be really cool

  • @charlestheninja
    @charlestheninja 4 года назад +408

    I just felt completely stupid after watching your programming skills.

    • @mohamedshaban3174
      @mohamedshaban3174 4 года назад +25

      didnt we all ?

    • @DeGandalf
      @DeGandalf 4 года назад +20

      Isn't this the case in every video?

    • @CodingJedi
      @CodingJedi 4 года назад +4

      DeGandalf isn’t that to point to make us feel that way ?

    • @ThisIsTheInternet
      @ThisIsTheInternet 4 года назад +9

      What's left out is the hours involved in reaching the next iteration

    • @aikou2886
      @aikou2886 4 года назад +2

      I mean... who didn't?

  • @ShadowHunter120
    @ShadowHunter120 4 года назад +2

    I always found it interesting how in portal 2 the entities were basically being cloned to work with these portals so you can have objects just chillin halfway through it convincingly.

  • @coderbunny5653
    @coderbunny5653 2 года назад +3

    8:43 me when i try to do literally anything

  • @CosmicComputer
    @CosmicComputer 4 года назад +3

    Those LP clouds though! How? You are awesome Seb, thanks for the video!

  • @MaharshiPandyaJanam
    @MaharshiPandyaJanam 4 года назад +6

    You are doing a really great job! To make people UNDERSTAND something instead of just showing what you know! One of the best channels I found in these days to keep learning. Keep growing.

  • @chriswaller8780
    @chriswaller8780 Год назад +1

    @6:20 that's some kerbal space program music, right there

  • @To-mos
    @To-mos 3 года назад

    I love how simple and straight forward this guys work is. Nice job sticking with the KISS method!

  • @KasperSOlesen
    @KasperSOlesen 3 года назад +3

    Awesome... I have been looking into making portals for a few years now, and this is the most complete example and explanation I have found so far dealing with pretty much all the problems you can run into.
    Except getting light to work through portals... but not sure even Portal got that implemented.

  • @jomy10-games
    @jomy10-games 2 года назад +4

    This is amazing! I’ve seen many people code their own portals, but this is by far the best one I’ve seen!

  • @gamehero5651
    @gamehero5651 4 года назад +1

    Sebastian, you're hands down the best Unity resource on RUclips. Keep doing what you're doing!

  • @Schwifty95
    @Schwifty95 2 года назад +2

    You are an absolute legend and my idol for problem-solving and coding in general.
    I agree with what have been said previously in some comments here: "You are the Bob Ross of coding."

  • @AnselmWiercioch
    @AnselmWiercioch 4 года назад +5

    "wait, did I open ksp in the background on accident?" ... "oh, same royalty free music. Got it."

  • @R3W3W
    @R3W3W Год назад +4

    I come back to this channel often, but I often think Godot is more aligned with Sebastian's vibe. Unity seems like it has more technical support so maybe it's a situation of having less potential road blocks toward ideation. Easier flow state because you avoid running into engine problems. Who knows.

  • @alextrollip7707
    @alextrollip7707 4 года назад +1

    You're a mad lad.
    Thank you for displaying your journey for each coding adventure.
    It's really interesting work.

  • @jacktjong1266
    @jacktjong1266 3 года назад +1

    I love watching random Unity videos with random cool mechanics, cause even though this portal stuff is something that I'm probably not going to implement into the game I'm working on, you actually gave me a perfect solution for an issue I was running into with deciding which way my player should be moving down a zipline when hooking onto the zipline from anywhere that's not either end point!

  • @Hawkspire
    @Hawkspire 4 года назад +4

    I always love seeing these in my subbox, great stuff man!

  • @DispatchCenter
    @DispatchCenter 4 года назад +5

    This is the best implementation of portals I've ever seen in unity. Making the "portal" a cube and slicing the 3D object blew my mind when I saw how well you solved some of the technical limitations I'd ran into previously.
    Simply amazing.

  • @dominikkorbely5809
    @dominikkorbely5809 Год назад +1

    i didn't think code could sound as threatening as VOID AWAKE

  • @thiamath
    @thiamath 4 года назад

    Genious!
    I love how you document every special case and point that I'm completely unable to guess at first glance making yours, the best tutorials I've ever seen.
    Congrats dude! You makes this feel so easy to do!

  • @richtourist
    @richtourist 4 года назад +3

    Apart from this whole video being great and really interesting, I love the end sequence too.
    The way the blocks fall through the first portal, with the second one angled so they go through the first again, but at a different angle so they exit the second at just the right angle so they fall back through the second out of the first and then, my favorite bit, the yellow one hits the tree with a gentle thud. Absolutely beautiful!
    Did that take long to set up, or just happy accident?

  • @Midnightmarth
    @Midnightmarth 4 года назад +4

    I am so thankful for your documentation of your progress. I really wish I knew how to understand the maths behind all the projects you do accomplish. Im just a simple ReactJS web developer and I have absolutely no clue where to even begin to learn any of this. I really want to become a solo game developer and clearly have a long journey ahead of me. Im happy I subbed as there is so much stupefying content on this platform and it's a breath of fresh air to watch this type of content, keep up the great work.

    • @mds570
      @mds570 2 года назад

      How's it going?

  • @Ch17638
    @Ch17638 3 года назад

    Absolutely amazing watching you chip away at the issue you face when creating something like this , I have been coding information systems for 13 years now , but this is next level

  • @gaboandres
    @gaboandres 4 года назад +11

    You should do a Shader programing tutorial Series!

  • @lukeystuff
    @lukeystuff 3 года назад +19

    Coding Adventure: Aperture Science Handheld Portal Device

  • @adheesh2secondsago630
    @adheesh2secondsago630 2 года назад +1

    1. Use stencil buffer to avoid flickering I guess.
    2. You could reduce the rendering cost of recursive portals. I m not a unity guy but I know opengl and we have something called *instanced rendering*. Now here is a bit of maths:
    no. of images observable(n) = (360/x) -1
    {x => angle between portals}
    ∆ MAKE SURE: x can be zero. That case we can scale and map the texture recursively untill it reaches pixel small or so. Else render n times. (If n is very large we can have a limit fir safety.)
    Now, rendering them. You could really instance them n times and render out at the same vertices. In opengl we have something called *gl_InstanceId* for each instance we have. This can be used to give scale down effect (by transforming the camera points u calculated.) Now we pass this and instanceIds to fragment shader as input and if the fragment lies outside the area assigned to that instanceId we discard that fragment. Overall this process would be much much optimizated then re-rendering everything like u are doing. Draw calls are expensive man!
    But I never could implement this I would be trying to write and share to community who could help me with implementation.

  • @DeathByFilmStudios
    @DeathByFilmStudios 3 года назад

    I love how condensed your code for moving the camera is. Other tutorials have at lease 8 lines and use quaternions and stuff. You managed to get it done in two lines!

  • @ABaumstumpf
    @ABaumstumpf 4 года назад +26

    One "solution" to the infinite recursion:
    Why render the scene again anyways?
    2-3 steps deep is enough of realtime rendering, for the deeper frames just use the previously rendered frame as a texture.
    It is no longer realtime and you would see changes "slowly" propagating through the portals, so teleporting right into such a position would at first show a lot of black. But imo a decent tradeoff as it only requires a bit of memory for the texture and for most scenarios looks fine with far less recursion and rendering needed.
    imgur.com/a/YNO65FB
    The orange lines would be the current depth of rendering, at that portal-plane a previously rendered frame is projected, giving and effective rendering that appears like the light-blue part was rendered too, but that is only the texture of the last rendered frame. if there can be a lot of recursions (near parallel portals) then this should give a quit decent effect but moving around would introduce some wavy-effect.

  • @electricanimation3379
    @electricanimation3379 4 года назад +16

    Omg u might be the most hard working dude on yt learns blender and unity how to code and write algorithms to visuallize the code and edit the video all with commentary. Like wow that’s a quick sub

  • @gorkemvids4839
    @gorkemvids4839 2 года назад +1

    I've been using unity for 4 years and this guy is still way ahead of me.

  • @harpernicholson1
    @harpernicholson1 8 месяцев назад

    the portal game tutorial was the first of your videos i ever watched, and it at the very least got me to think about math and projection in 3D space as a 9 or 10 year old. very fond memories of my early days with unity :) you are an absolute master with your shaders and procedural mesh stuff. such an inspiration, i love the nature of your work.

  • @sss-tw3jh
    @sss-tw3jh 4 года назад +81

    Can you answer the age old question of what happens when a moving portal falls onto an object? Does the object go flying out the other side with the same velocity of the moving portal, or does it simply plop out the other side?

    • @AntonioNoack
      @AntonioNoack 4 года назад +21

      The answer is "kinda" simple: there is no definite answer, because of relativity.
      Is the teleporting process happening in portal space, or in "world space"?
      Happening in portal space means, that the object just will keep its velocity (negative falling velocity) relatively to the portal, while happening in world space means, that it will keep its velocity (0) relative to the world.
      If the two portal sides are facing in the same direction, this will be the same result for both cases.

    • @harbingerofcrazy5189
      @harbingerofcrazy5189 4 года назад +36

      Answer: depends on your implementation, whatever you want to happen happens, or to be more accurate whatever you instruct the computer to do , it'll do.

    • @r033cx
      @r033cx 4 года назад +3

      When portal is moving objects around it don't gain velocity with it, so I think it would just pop on the other side
      It's kinda like dropping hula hoop on it I think

    • @happybunnywabbit
      @happybunnywabbit 4 года назад +4

      There is no reason to think the object would gain the portals velocity. Even though this is complete science fiction, it would be safe to assume you would just ''plop" out from the other side.

    • @thundersheild926
      @thundersheild926 4 года назад +12

      Not necessarily. If we consider a universe with just an object and a portal, the object having velocity would be indistinguishable from the portal having that velocity. So, if this were happening in the real world, the objects end velocity would be its current velocity - the portals velocity. However, if I'm understanding this specific implementation of portals, it doesn't care about the portals velocity So the object will simply "plop" out the other side.

  • @Austeja608
    @Austeja608 4 года назад +32

    Welcome to aperture science

  • @Kragatar
    @Kragatar 2 года назад

    lol That first teleport test was hilarious.
    "Filled with grief and rage, I began debugging"... such a relatable feeling.

  • @herouxandrew
    @herouxandrew 3 года назад +2

    This is by far the most comprehensive portal implementation I have seen. An area of improvement would be lighting through portals. Very nice work!

  • @Lloyd2112DT
    @Lloyd2112DT 4 года назад +18

    This channel is, frankly, too good relative to the number of views it gets. Something is clearly wrong with the world.
    I'd love to see you cover non-Euclidean space rendering (à la Stanley's Parable) where you can walk down an entire hallway/region where space is compressed or expanded. But it seems like it'd require ray tracing to get the visuals to behave properly. Also, I'd love to know how proper ray-tracing would account for portals.

    • @alcejaylos.4257
      @alcejaylos.4257 4 года назад

      I opine!

    • @Dimencia
      @Dimencia 4 года назад

      I mean, most of that is probably this. If you want an endless hallway, stick a 'portal' on one end that's the size of the hallway, and done. When you want to let them out, get rid of that portal

  • @ryan1696
    @ryan1696 4 года назад +5

    Looked at the description and said it in GLaDOS' voice "Experimenting with portals, for science (you monster)"

  • @darrinhert9296
    @darrinhert9296 4 года назад

    Fantastic stuff! Love the detail and thoroughness you put into your investigations.

  • @emlyndewar
    @emlyndewar 4 года назад

    This blows my mind. Explained like it’s so simple. Great effect.

  • @Pomodorosan
    @Pomodorosan 4 года назад +4

    7:00 the portal camera bumps into some trees as you jump here, hmmm
    ah hah 12:25

    •  4 года назад +1

      i made the same comment :D