Bevy game development tutorials and in-depth resources
taintedcoders.com
taintedcoders.com
I built a few games in WASM and was shocked to see many of the bevy variants larger than the Unity versions.
There’s definitely a market for rust game engines but it seems that no one’s hit the sweet spot yet.
As far as file sizes go, I'd be really interested in how a Rust compiler that didn't monomorphize so much would perform. Right now you have to modify the source code to write polymorphic generic functions, but it doesn't strictly have to be that way (at least as far as I can see).
I wouldn't use Bevy for a web only game either, especially while it's still single threaded on WASM.
The way Bevy's internal state is so easily saved and loaded is convenient for this.
Bevy gives you a very nice ECS to model your app but compilation can be slower than hand crafted code, while not using it gives you tonnes more code and the complexities that come with it, just to compile faster?
I also don’t think that other solutions are “tonnes more code.” Any code will explode in size if poorly written. The same is true for bevy.
Calling that "not very notable" for an indie title is pretty ignorant.
Rust has like 2-3 game engines and a bunch of bindings.
It also adds easy to move goalpost of notability, that only accounts for luck and age, not actual capabilities.
That's a single data structure. People say binaries start at 50 MB for a hello world program and 700 MB for the debug binaries.
https://old.reddit.com/r/bevy/comments/16wcixk/cant_figure_o...
Are you asking?
but calling it a "single data structure" is a bit reductive.
No it isn't. It's like a tiny database. Depending on how someone implements it, it could use arrays, hash maps and b-trees. There is no universe where this means a binary that does nothing should be 50 megabytes.
No it isn't. It also handles system management and concurrency, basically the main loop of your application.
I also would be cautious of assigning the blame of the binary size onto the data structure on its own.
What does that mean?
concurrency
Some data structures and databases deal with concurrency.
By system management I assume they mean the APIs bevy offers for scheduling and sequencing systems and events so your game logic remains modularized while still running in the correct order.
As I have previously stated, I wouldn't blame the data structures used behind Bevy just yet, given Rust's tendency for making bloated binaries. What is taking the most space in this 50MB binary? How does it scale with the complexity of the application?
But, out of curiosity, do you also consider the Linux Kernel also a data structure?
To be clear you think an ECS implementation is 50 MB?
But, out of curiosity, do you also consider the Linux Kernel also a data structure?
Do you think a spreadsheet the holds function pointers is a kernel?
No.
> Do you think a spreadsheet the[sic] holds a function pointer is a kernel?
Do you think an entire engine, including its system scheduler, is a spreadsheet? If so, shouldn't be hard to apply the same argument to any kernel. Of course, it all relies on your definitions and sense of reductionism.
That's an ecs data structure and a system scheduler. If I make a vector and a system scheduler, vectors don't suddenly have system schedulers, they are two different things.
You register systems (functions that operate over the components)
That's just adding a function pointer to a field.
ECS isn't a data structure tho, it's a pattern. You must be referring to the component storage. That's, at best, half the equation. You do realize the discussion is about the 50MB program, which uses both the component storage, the system scheduler and other features, right?
> That's just adding a function pointer to field
Just as much as creating a new process, through the IP/PC field in the TCB. Don't know why you focused on that particular point, but sure.
Every implementation out there is a data structure. You keep talking about things that use it and then lump them together. That's just you.
You do realize the discussion is about the 50MB program, which uses both the component storage, the system scheduler and other features, right?
No, the first person I replied to said that justified a 50MB program. A few other software components don't make any sense either. 50MB is not something you get to with 4 or 5 parts of a game engine. That's the stripped binary too, it was originally 700MB.
Don't know why you focused on that particular point, but sure.
You brought it up, I'm not even sure what point you are trying to make.
Examples?
> 50MB is not something you get to with 4 or 5 parts of a game engine.
Depends on the engine's architecture, runtime, etc. Again, don't know if you are blaming the bloat on those components alone (it seems like you are), but you haven't established a direct link between said components and the bloat, thus, it's hard to properly reason about the tradeoffs given that we don't know how said bloat scales.
> That's the stripped binary too, it was originally 700MB.
Actually, no. Rust doesn't strip binaries on release by default. There's a reason there's a guide about minimizing Rust program sizes.
> You brought it up, I'm not even sure what point you were trying to make.
You are the one who nitpicked over "You register functions", ignoring the rest of the sentence.
No, it depends on excessive dependencies that themselves have dependencies.
There's a reason there's a guide about minimizing Rust program sizes.
And 50 MB was the stripped version, what is not sinking in?
Not necessarily. Not every dependency will generate code. Furthermore, those dependencies of dependencies are rather small. If you're so certain that's the case, then provide an actual analysis over a case. Would be an interesting read.
> And that 50MB was the stripped version. What is not sinking in?
From the reddit post you linked:
> paholg: Rust debug binaries tend to be large. What's the size of you compile in release mode? > talentedBlue: 49M. looks more reasonable > CleanCut9: You can strip the release binary to get it even smaller if you want
What didn't sink in is the fact that you don't seem to have read the linked thread appropriately.
Who said that?
Furthermore, those dependencies of dependencies are rather small.
No, they add up to 50 MB.
Your assertion that dependencies are the cause of the bloat is only trivially acceptable if, at least, every dependency actually contributed into the binary size, nevertheless in a significant manner. Thus it is a counterpoint.
Which brings to...
> No, they add up to 50MB.
You are just asserting this. The thread you linked doesn't really support this. So I'm asking for actual proof, like a disassembly, or analysis through other tooling.
That makes zero sense. That's like saying your luggage can't be too heavy because it contains a feather. Think about this super hard.
So I'm asking for actual proof, like a disassembly, or analysis through other tooling.
You think you need disassembly to see file sizes?
There's nothing to think here. This analogy is stupid at best, profoundly ignorant at worst. We both agree that the binary is 50MB (the weight), so the "luggage can't be too heavy" is already nonsense.
> You think you need disassembly to see file sizes?
I mean the cause for the 50MB, if that wasn't clear (somehow).
No it isn't. If you could explain why you would have already. Saying that some dependencies aren't heavy so the problem isn't dependencies doesn't make any sense. Huge bloated binaries are from lots of bloated dependencies because people aren't actually writing 50 MB of stuff to do what they need.
I have my suspicions. But I rather speak with certainty rather than spout unfounded hypotheses as facts.
> Saying that some dependencies aren't heavy so the problem isn't dependencies doesn't make sense.
If I did say that. I said that isn't necessarily dependencies, because you have yet to prove it. If you do prove it, then that is that. As of now, all you've shown is that thread.
> Huge bloated binaries are from lots of bloated dependencies because people aren't actually writing 50MB of stuff to do what they need.
Restating what I've said prior, you are just asserting this, but have yet to prove it. For starters, what are the specific bloated dependencies? How much space does each dependency actually occupy in the final binary? A disassembly would answer those really quickly.
Not a single data structure, that's for sure. Have you ever programmed before?
Even though you have to actually substantantiate this, for the sake of brevity, let's go with it. All you have crossed is a single potential cause, not proven a particular one.
> Have you ever programmed before?
Let's say I haven't. How would it impact your argument? Whether I'm a programmer or not won't magically substantiate your position.
That explains why what you're saying and focusing on doesn't seem to really make sense.
Even though you have to actually substantantiate this,
Data structures are parts of programs that hold data. Have you made a data structure before?
Or it could be just you. Even presuming you're a good programmer, that wouldn't make your arguments good by default.
> Data structures are parts of the program that hold data.
Not according to Wikipedia:
> In computer science, a data structure is a data organization and storage format that is usually chosen for efficient access to data.
ECS doesn't stipulate any storage format, as shown by the previous definitions, only that your application will be architected around Entities, Components and Systems. How they are stored/managed is up to the programs/frameworks/engines to decide, and this storage is just one concern an implementation may have, just like how storing ViewModels is just one concern of a MVVM framework, but not all.
I'm no stranger to using unorthodox definitions, but I would prefer if you were upfront that your definitions are unconventional, rather than pretend that they are common sense without citing any third party authority.
From HN guidelines:
> Please don't post shallow dismissals, especially of other people's work. A good critical comment teaches us something.
No one thought that or said that so I don't know what point you're trying to make.
If you go to the comments I replied it was someone saying bevy compiles slow and has excessive bloated binaries. Someone else replied that you get so much, like ecs. Then I said that ecs specifically is just a data structure and has no reason to bloat binaries to be 50MB for an empty program that does nothing.
You're replying about things no one was discussing.
Then, you used this reductionism to question whether the 50MB binary is worth it. And that's ignoring the fact that there are ways to cut it if you wish, as mentioned in the reddit thread. And then there's the issue of whether it will actually matter for a full game.
From [1]:
> Entity component system (ECS) is a software architectural pattern. An ECS consists of entities composed of data components, along with systems that operate on those components.
From [2]: > ECS ("Entity Component System") describes a design approach which promotes code reusability by separating data from behavior. Data is often stored in cache-friendly ways which benefits performance.
Of course it will be used somehow. I don't call a std::vector a "vector system" because someone uses it, but I guess people think using this data structure makes it a "system".
> Data is often stored in cache-friendly ways which benefits performance.
Notice it says often, not always.
And bear in mind, generally, data structures aren't just about storing data. They are about storing data in a very particular way.
That's data, so it stores data, meaning it is a data structure.
So your assertion about it being strictly meant for data storage is just wrong.
No, using a data structure doesn't mean it isn't one.
Notice it says often, not always.
This doesn't matter. You're way off the map in what causes 50MB binaries.
data structures aren't just about storing data. They are about storing data in a very particular way.
Same thing, you're pretty deep in the replies and still not making a point.
Technically, the component storage is, at best, a ADS. But that's grasping at straws given that you can just store components directly in a function's stack frame. Still, the component storage isn't "the ECS" in the same way that a service injector isn't "the Clean Architecture ", even though you'll always have them in some form in each.
> No, using data structure doesn't mean it isn't one.
Now, where did I say that?
> This doesn't matter.
For the discussion of whether ECS is a data structure, it is, given that you previously stated that ECS was meant for storing data, and "often" contradicts that.
> You're way off the map in what causes 50MB binaries.
I haven't asserted anything about it. You did, and you have yet to prove it.
> Same thing
Pretty much everything stores data in someway. Which brings us back to the "kernel is a data structure in your eyes?" question from earlier. I don't think it is me who isn't making much of a point.
Edit: checking now ADS is a too literal of a translation (English isn't my first language). The more appropriate term is ADT.
ECS is an abstract term for a data structure. Have you ever programmed before?
Sources? I have cited mine for why it isn't.
Also, remember, it's not my responsibility to search to prove your arguments. Burden of proof is on the claimant, as it goes.
Taking a cursory look (which is already beyond my responsibilities) at https://github.com/redxdev/ECS/blob/master/ECS.h, by searching "class ECS" and "struct ECS" and "EntityComponentSystem" wields no results.
No, they aren't.
> You should probably learn how to program before arguing all this stuff.
Notice how I didn't reveal whether I program or not, yet you still made assumptions about it. I suspect that you either are a poor programmer or a troll.
Didn't you just say something about "ad hominem" (even though you used it incorrectly, pointing out something negative if it's related is not ad hominem).
You don't know what a data structure is or what a class does or doesn't do, that's not something programmers have to worry about. They don't have to consult wikipedia for a definition.
Since you failed to cite any third party source for definitions, whether your definitions are actually conventional depend solely on your authority as a programmer, in contrast to me, who cited Wikipedia (and there are many others I can cite too). An attack on your authority is no longer a fallacy, but, towards me, it is, since I never relied on my authority as a programmer.
Never mind the fact that being a good programmer doesn't mean you know the definition of technical terms.
Never mind the fact that being a good programmer doesn't mean you know the definition of technical terms.
Yes it does. How would you know?
> Yes it does. How would you know?
Better question: why being a good programmer guarantees you good knowledge about technical definitions? Being a good mason doesn't mean you have the formal knowledge of a civil engineer.
Edit: wow I’m way off… it must have been the 90s when I checked this lol
I’m actually seeing if I can build a parser using bevy_ecs just because the way their state machine works, it looks like it would be fun
- could someone kindly share some resources on c++ game development
- here is what i have
- https://gamedev.net/tutorials/
- https://shader-learning.com/
- https://www.gabrielgambetta.com/client-server-game-architect...
- https://github.com/0xFA11/MultiplayerNetworkingResources
- just a headsup, i am looking for 3D game development without unreal, unity , godot or any of those engines
Then your unfamiliar readers can first hop to bevy.org to see what it's all about.
This is huge, thanks. Unfortunately many Bevy resources became stale (the Bevy cookbook was even abandoned, there was little interest in keeping it up to date and so there were many sections for, say, Bevy 0.12)
Already seems like a great resource to me but it's still WIP.
I now default to the examples, but a book would greatly help.
Quite the dedication to a free resource!
That is true for all game platforms, experience takes care of it, don't give up.
About compilation time concerns, it doesn't seem to be a problem with Bevy, there's a fast compile mode with very reasonable performance.
However, I didn't see any scripting, there are scripting options for rust, it would be good to have bindings for some rust-like scripting.
I think a lot of the way I try and structure my Bevy apps comes down to trying to separate the rendering from my game logic. Its very easy to confuse the two responsibilities.
Coming from the web and Ruby I find the lack of automated testing and TDD to be foreign to me. So I've been trying to figure out patterns that make my games easier to test. Hoping to write about it soon.
ECS is a pretty old idea, built on concepts that are even older. I was playing around with an ECS-like engine of my own in C over 10 years ago, based on blog posts and talks that are now 20-25 years old. Even the Wikipedia article for ECS can trace the origins back to the 1960s. (Though obviously it hasn't been applied to video games for quite that long.)
Nowadays I'd probably reach for Godot and Kotlin if I just wanted to build a game in an ergonomic language on a solid foundation. You could still apply ECS concepts there, as well.
Rust has testing in the standard library -- IMHO Bevy is far easier to test than most game engines because it's "just rust". You can test game logic by starting headless apps, proding the ECS, and making assertions on the results.
For acceptance tests I've dusted off cucumber (after ten years of not thinking about BDD), as I it works great with Bevy
Actually I just checked the "official" list and they only list the closure syntax which seems pretty minor:
can someone link to some of those paid resources?
He's also got plenty of free resources which I love to watch: https://www.youtube.com/@chrisbiscardi