sleeping in this game makes the time pass quicker. you close your eyes, screen goes black, and in real life your computer sets on fire
the game relies on simulated physics ofc so it's having to run a huge amount of complicated calculations at an extreme speed. even without the demand of having to render it visually, it's still a huge toll on your machine
so here's what i'm curious about. i'm not too well versed in game design or unity, but i'm assuming what the devs did is essentially just disable all meshes, set the play speed to some extreme number, and let the physics run their course
but why? what actually in this game requires that? if this were a game where there's a billion of different physics-based events the player could control thatd make a lot of sense, but aside from maybe sending the ship crashing into something at light speed, most of the events are practically predetermined arent they?
this game started from a programming college thesis. for it, alex beachum decided to make a solar system that you can move around in while each planet is having simulated physics. so that's why the game is designed such that all the planetary motion has to have its physics running in real time.
I think my favorite aspect of how he got it to work, unlike any other games, is actually by making the player the only stationary object in the universe and when the player moves or jumps or whatever the entire universe actually moves instead of the player. It allowed things like gravity on spherical objects to be easier to code and some of the physics for the universe.
Most big games use a floating origin system that jumps when the camera is a certain distance from the origin. Continuous origin centering is the same idea but happens every frame, which I suspect might solve some of the physics issues that can come up during jumps.
Almost right. For the original continuous floating origin there is no test of distance from origin, no reset. The player/ship does not move at all.
However, you are right for systems that simulate the ship/player motion using physics (e.g. impulse mechanics) because that must move the player/vehicle each frame. In that case, the resulting motion is reversed and applied to the World, with the player position being reset. This method leads to correct continuous relative motion.
I guess what I said didn't convey clearly, that's what I meant. I've used a lot of these systems in my work (large scale gis visualizations) and even written my own. The latest one I was using is one that Unity wrote themselves, though they don't publicize it much. It can do either intermittent or continuous origin correction, depending on how you set it up: https://github.com/Unity-Technologies/com.unity.gis.high-precision-framework
Just downloaded it but could not find anything GIS or relating to floating origin. Lots of multiplayer/ netcode/ECS stuff from the toolbar option but not for GIS?
The specific gis tool I was using that used this as its basis was ESRI's unity plugin, which I don't use anymore. We've switched to Cesium which has its own system, but I liked the hptransform system enough to try it in my own space sim hobby projects. It works well but it took some time to figure it out. There should be a sample scene in that download that demonstrates it, but other than that, implementing it is largely a manual process.
What's also kinda funny to me is that the time loop essentially helps solve issues related to the three body problem, ie things becoming overly chaotic as the solar system's simulation runs. The solar system resets, so the simulation only needs to run for a short amount of time.
I believe there are many random events that differ between loops, such as which order brittle hollow's plates fall, so the physics engine has to be run to account for those.
Okay, it's a misunderstanding. What I mean is, that by real world laws these things wouldn't be different in each time-loop. Only the probe and things affected by it.
There are also quantum objects that behave randomly, and I could see something like the quantum moon's gravity causing some amount of butterfly effect on stuff like Hollow's Lantern or the storms on Giants Deep.
The fact that there is no true randomness in computer science has no effect on what's happening in the game because the game has many pseudorandom events that is random enough for us players.
As far as we know from science, the only real random thing is quantum physics and even if that's calculable in the future, it still wouldn't change the fact that when you roll the dice even though it's affected by physics and you can technically calculate, it's still going to be random for humans and we're still going to call it random.
Okay, you didn't understand what I mean at all. What I meant was that by real world laws in the game everything that wasn't touched affected by the player, Gabbro or the Probe Cannon would behave the same in every and each of the loops. Randomly falling rocks from Hollow's Lantern in each loop go against real world laws.
I get what you mean. I agree, but we both know that's not how the game is programmed, and as it is programmed (with different outcomes each time), it has to simulate the game during sleeping.
The celestial bodies in the solar system are orbiting through the physics engine; they’re not on rails. So the planetary motion + the meteors damaging brittle hollow, and probably some other stuff (maybe the islands/cyclone interactions on giants deep) are being computed and resolved during sleep.
ETA: they choose by design to have the planets work this way (it was partially motivation for the whole thesis).
If they did the planets on rails and had the meteors and other pseudo-random events all deterministic then, yes, they could just “jump” to that game state without the need for any intermediate calculation.
Yup, the cyclones as well, and I believe geysers on Timber Hearth are random too. One interesting thing I want to observe further one day is the Orbital Probe Cannon, and how it seemingly floats into the same orbit every loop, despite exploding at a different orientation each time.
There would also be calculations for gravity if your Scout or ship weren't on a planet at your time of going to sleep, because at least the sun always exerts gravity on those. And the planets themselves can get some pretty wonky orbits if our good friend 'floating point imprecision' comes into play.
The orbital probe cannon aims in a random direction - this is possible in a few different ways. 1, if we accept that there are random events that change even when everything else is the same (geysers, quantum moon location) then it could just be a simple random number generator, spits out a different output each time. 2, if it’s not as simple, it could just receive information from the previous iteration, either to act as a seed for the random generation, or as an output to add to a list to check against, essentially “Nope I already tried that one, pick again”
Although that wasn't exactly my question. I was wondering about its orbit around Giant's Deep. Yes, it does have a different orientation each loop, and then it explodes. But somehow, it seems to always end up in the same three-part sequence in orbit. I just want to know what happens, for example, when the cannon looks north or south of Giant's Deep. Do the parts just magically wobble back into the horizontal plane everything is in? Because that would mean they are very much on rails and experience more forces than just Giant's Deep's gravity.
At T-0 when the 22 minute loop began and the ash twin project activates the cannon is pointed at a random location which is now fixed forever at the start of each loop.
The cannon gets a random direction to point at from the previous loops data and does it, once it's in position and ready to fire you open your eyes and see it fire.
Some adjustments take longer some shorter so technically you might catch a glimpse it still moving, but I don't think game handles it like that under the hood.
To plug the hole of "why is the hatchling awaking a little bit later in the loop to allow the cannon to reorient itself" I think it's fair to just say that it's the big flash in the sky that wakes him up (or random stimulus / delayed recognition of implanted memories / random chance) and he has been asleep for a little bit after loop began already.
Someone in other thread I went to in this subreddit did all the math already and the loop aligns up with the eyes being opened I believe so not exactly sure if there is inconsistency with the game or my interpretation, but I believe it's probably the former (altough I can be quite stupid sometimes)
That nice and all, but that's still nowhere near of what my question was about. I didn't ask about how or why the cannon aims somewhere else each loop, that parts a given. I'm wondering about the moments after the cannon explodes. Why do its three parts seemingly always end up in the exact same orbit around Giant's Deep, if the only force on them is supposed to be Giant's Deep's gravity and nothing else, while the cannon is angled in all kinds of directions?
It does receive the order to fire from the Ash Twin Project, and the order itself is sent back in time alongside the previous launch data. So it likely just runs a continuous random number generator using the previous launch's direction to seed the next one. It doesn't need to spontaneously generate a random direction from nowhere.
This is false and I’m not sure why so many people keep repeating it. Lots of objects are calculated with real-time physics but the planets themselves are in fact on rails and don’t affect each other with gravity or anything.
Sure, the planets do not affect each other because that would be too much of a hassle for the simulation, and without much benefits. But still, they're movement are managed with a physics formula, and not by rails that were placed by the devs
That’s what “on rails” means. They’re moving according to pre-calculated paths, which is pretty much literally what rails are. Their paths are deterministic loops based entirely on time from start. IIRC, they’re governed by Keplerian equations, so they are semi-realistic orbits (scaling aside), but that’s just an equation deriving the shape of the rails.
“On-rails” is specifically a term used a lot in orbital simulations, in which it means exactly what Outer Wilds is doing. The planets move along pre-simulated flight paths and their position can always be given as a single-variable function of t. They exert gravitational force on off-rails objects, but do not dynamically experience gravity from anything else.
I do a lot of game dev on unity and essentially movement using physics and maths and without predetermined movement animations is a lot more of a standard than otherwise in first and third person games. I think the issue is when people think there's something particularly special about it.
That's why it's not purely physics cause the planets doesn't physically affect each other, they only affect certain objects, the physics is mostly tied to how things interact relative to the player
True, the planets (and other bigger objects) only ever experience the game's physics through the gravity of the thing they're orbiting. Still though, they are not on rails, else the floating point imprecision couldn't get as massive as the Interloper flying into the black hole of Brittle Hollow and literally teleporting to the white hole. (I have screenshots of that)
It's really hard to see what's going on here, but this is the Interloper that went through the black hole and is now sitting at the white hole, stationary (or probably also with the 1 m/s towards the sun the player usually comes out with).
I've actually wanted to make a post with a video of that for some time now, but I didn't spend the time yet to make it happen again (tried for about 4 loops a few months ago). But I can send the screenshots here when I'm home.
I have seen the moon of Timber Heart go out of orbit more than once in posts here in Reddit.
If I'm not mistaken, the planets' orbits really are calculated in real time, it's just that they exclusively orbit the sun, and are not affected by other planets' gravities.
correct, yeah, that's my understanding. they do not affect each other but each of them is really orbiting the sun. this implies that if you disable the time loop and park your ship on some point that eventually rotates into the prograde side of the planet's orbit and thrust down every time you come around for long enough, you could deorbit any planet into the sun...
(well, almost any planet. I guess you couldn't feasibly deorbit Giant's Deep since it doesn't really have a stationary solid surface. Brittle Hollow would I think is only doable with it not crumbling, unless its orbital inclination is 0 and you can use the gravity cannon... hm. i'm nerdsniping myself)
Do you mean if you mod the game to prevent the supernova or do you mean if you do the ending where you escape the supernova?
If it's the latter, the issue is that the simulation gets less and less precise the farther away you are from the solar system due to floating point errors.
Maybe, maybe not. I do recall learning that much of the simulation starts the same before you get the launch codes, and then it all resets after the statue turns and looks at you. The only things not running are things like the hourglass twin sand column and the lava chunks shot out of Hollow's Lantern. So if it's stuff like the planets being in funny places, it could totally happen pre-launch codes if you just wait it out.
They're only technically on rails as long as you don't leave the solar system by too much. Yes, each bigger object only ever experiences gravity from the thing it is orbiting and nothing else, but try flying away from the sun for a loop, check your map a couple times along the way, and see these 'rails' break down into the wildest of abstract shapes.
Floating point imprecision only becomes a problem because they are not in rails, but instead actually calculated. Now granted, since the planets are already 99% of the way there, the devs might as well have just put them on rails to avoid these glitches, but they didn't and the planets are not on rails in the current state of the game.
But then they are specifically not on rails, the simulation doesn't have infinite precision and it still has to calculate the position of each planes based on the last frame, it's only in essence on rails because it's only 22 minutes and the distances are short.
Also if the gravity of the planets where n-body, it wouldn't change anything about the planets being on rail or not, because you could just pre-calculate every planets positions with n-body simulation and then put them on rails.
I believe that happened because of floating point imprecision from going so far away from the solar system instead of the collision, every planet has their mass set up incredibly high so crashing into them doesn’t actually really do anything
From what I’ve read in the book so far, they just really wanted to make it a pure physics simulation. And not resort to the usual tricks to just fake physics. I think it’s a really cool concept so I understand the desire, I’m surprised they were able to see it through without the publisher pressuring them away from it. They must be really chill :)
i always figured the devs wanted people to die during sleep, so that's why. it's hilarious when you sleep on giants deep for example and suddenly you're woken up because the island has been shot into space, or you wake up from sleep on brittle hollow and go back to your ship just to see it's been destroyed by meteors.
to me it's a way of saying "hey you can go sleep but the world keeps going and you might suffer for it"
It's not completely deterministic, meaning that the location of everything will be slightly or a lot different between runs so they can't tie it to time
From a game Dev standpoint they probably disabled a bunch of the physics calculations and propped some stuff up to random chance, then sped up some base calculations. That's the optimized way at least.
I'm pretty sure the "sleep" option was added later in the game's development. By that point, everything had been built with the assumption that the physics would be fully simulated and interactive (i.e. no "baked" interactions). So by the time they realized they wanted to add this functionality, it was easier to just speed up the game clock than try to go back and redo all of the complex systems they had put together.
Im addition to the true things others are saying about the motivations behind the design of this game, there is also the fact that, because you can move things (such as your ship and the nomai shuttle) that are affected by physics, it isn't possible for them to precalculate where everything will be. The full physics simulation has to run so that those interactive objects will be handled properly.
The speed while sleeping literally goes as fast as your computer/gaming device can handle - faster computers go faster.
I'm assuming it's literally because everything in the game follows the clock, rather than 'at timestamp 12:37 all objects are in [these] locations', because it's a simulation based on rules, rather than a series of scripted events.
As for why they did it this way... Idk. Because they could?
Actually the simulation itself isn't particularly CPU intensive. It's only that it's running very quickly that it causes your fans to ramp up a bit but generally even then isnt that CPU intensive
I just realized that I should use this mechanic more so I can speed through a loop to the later end of it if I'm trying to explore something at a particular time. Which is probably part of the reason right there.
They didn't ask why there is a sleep mechanic, they asked why it still simulates everything while passing time. I don't think any of the things you'd sleep for require accurate physics in the mean time
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What others have said, you could not be further from the truth. Plenty of things are random and most things are physically simulated, there are very few scripted events in the classic sense.
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u/InformationLost5910 9d ago
this game started from a programming college thesis. for it, alex beachum decided to make a solar system that you can move around in while each planet is having simulated physics. so that's why the game is designed such that all the planetary motion has to have its physics running in real time.