Bevy 0.5: data oriented game engine built in Rust

https://bevyengine.org/news/bevy-0-5/

by _cart • 5 years ago

167 54 5 years ago

bevyengine.org

serverholic• 5 years ago

Huge release. Glad to see this engine is still making progress.

alice-i-cecile11• 5 years ago

Contributor here: there's so much cool stuff in this release.

I was personally most involved in improving the docs, the reliable change detection work (you can now detect changes no matter when your system runs, even skipping arbitrary numbers of frames), and a great deal of the other ECS work. AMA if you have any questions or requests ;) I'm particularly curious about "I'd like to use Bevy but..." stories.

anchpop• 5 years ago

Thank you for your contributions! I'm most excited about labeled run criteria and the other ECS improvements. For those not following along, the goal is to eventually implement statecharts [0], which are kind of a generalization of finite state machines that are more practical for specifying the behavior of complex systems. I think that's going to really put Bevy's ECS above most of the competition and push the field forward.

[0] https://statecharts.github.io/

kodablah• 5 years ago

I'm particularly curious about "I'd like to use Bevy but..." stories.

I am a game dev novice, but the concept I am wanting to develop requires mesh loading (fbx/dae), animation/skeleton/bone loading, and custom bone manipulation. Granted Bevy does seem to have the physics I need via the rapier plugin. I have been working with Godot to achieve my PoC, but would love to use Bevy instead. I admit to not keeping up with the current state of these features.

alice-i-cecile11• 5 years ago

Thanks for chiming in :) Animation is a common request, and definitely still not-very-usable.

Thanks to the work of lassade, our resident animation expert, I expect we should have basic animation in place for 0.6. For skeletal animation in particular, they've been prototyping with a crate of their own [0] to hook into Bevy that seems like an excellent proof-of-concept.

0: https://github.com/lassade/bevy_spine

hn8788• 5 years ago

I've been using Godot for some small gamedev projects, but have been interested in Bevy because Rust is my primary language. The Bevy Book stil says that Godot should be picked for any big projects; is there a rough estimate of when Bevy would be at a point where you'd be confident recommending it for a Next Big Project™? I know timelines can be tough to nail down, but even something like "a very long time" or "a couple of years" would be helpful. Thanks for your work btw :)

alice-i-cecile11• 5 years ago

Depends on your iteration speed, exact needs, and willingness to work on engine development.

Personally, I'm building my turn-based tactical RPG in it, which is absolutely a Big Project, but I'm not planning to release for a year or two, don't need complex 3D features and am devoting half of my effort to engine dev.

For single-player games that aren't very asset-heavy, I would say 3 months or so for UI to stabilize is a safe point to start work.

For games that have complex animation or sound needs, require networking or want to use a ready-to-use physics library, I'd estimate about 2 years from now.

If you're trying to build a game with very-little coding (and want something comparable to Unity or Godot), "a very long time" :)

beatothewitch• 5 years ago

I'm a novice game dev and I'm currently using Godot so i'd like to use Bevy but i'm waiting for an editor UI. What's the roadmap looking like for that?

alice-i-cecile11• 5 years ago

Great question; it's hotly awaited by a lot of the community. Rough (and very unofficial) road-map is looking like: 1. 0.6 (June 2021): First-class ECS-integrated UI solution is architected and released. Asset management, animation and scenes are improved. Plugin architecture and data-driven workflows get a closer look. 2. 0.7 (August 2021): Editor MVP launches as a separate application built in Bevy, focusing on supplementing code-first Bevy workflows with things like property inspectors, scene management, system visualization and so on.

Once that's launched, I expect that we'll be working on making Bevy more usable through the editor for low-code users, although the goal is to ensure that pure-code (and pure Rust) Bevy games have feature parity with anything you can do in the editor.

lazybean• 5 years ago

I really liked your (now abandonned) understanding-bevy book. So I'm so glad you are involved in improving the docs!

_cart3• 5 years ago

Lead Bevy developer here. Feel free to ask me anything!

EamonnMR• 5 years ago

What have the biggest challenges been?

pointernil• 5 years ago

Kudos! What an impressive collection of features and display of substantial development in almost all areas of the framework!

What's the current status of OpenGl Support? Any progress there? It would be really "cool" and inspiring to be able to develop on older yet otherwise good-enough hardware... thinking about all those very young future devs stuck with all that otherwise good-enough hardware here ;)

TheRawMeatball4• 5 years ago

We let wgpu https://github.com/gfx-rs/wgpu-rs handle our graphics backend abstraction, so our OpenGL support will come whenever they implement and release it. Currently, it seems to be a WIP.

kvark• 5 years ago

Please share what that hardware is. On Linux, Vulkan support starts at Intel IvyBridge, which is 8 years old now. Do people develop games on older computers these days? On other OSes, we have D3D12/D3D11 and Metal support.

smusamashah• 5 years ago

Has basic 2D drawing (lines, rectangle, bezier curve etc) added yet? I remember it was in the plans in the very beginning.

jamadazi5• 5 years ago

Officially, not yet, but there is a good community-maintained plugin: `bevy_prototype_lyon`.

TheRawMeatball4• 5 years ago

No, but the https://github.com/Nilirad/bevy_prototype_lyon crate does a very nice job here :)

sercand• 5 years ago

Is it currently possible to use Bevy with given MTKView on iOS?

We have already an app with thousands lines of code and we need to render a game like experience on a just single page. We can achieve this with SpriteKit or SceneKit but we need something on android as well. So we are investigating a cross-platform tool.

The given iOS example on Github repository creates the window itself but it not possible for us.

edit: It looks like bevy uses winit for windowing and it doesn't support this. So winit is the blocker here.

jamadazi5• 5 years ago

Bevy is modular, in the sense that you can remove higher-level parts/layers if you don't want to use them.

For example, you could use only the Bevy ECS if you didn't care about the rest.

You could replace `bevy_winit` (window creation using the winit library) with your own alternative.

the_duke• 5 years ago

I'd just like to mention that the release notes are one of the best I've read.

Same goes for PR descriptions like for the ECS v2 PR [1]. That's more text than half of open source libraries have documentation.

[1] https://github.com/bevyengine/bevy/pull/1525

CJefferson• 5 years ago

Is it a good idea do you think to use Bevy for a game yet?

I don't expect a concrete promise, but is to reasonably bug free, and is it likely to be "not too hard" to upgrade to new versions in future? Or should I wait?

alice-i-cecile11• 5 years ago

Depends on how quickly you're moving and how much polish you want :) Great for game jams and prototypes, not there yet for published games.

Reasonably bug free, yes. Not too hard to upgrade, yes. Are critical features missing or inadequate (audio, animations, networking, UI...), also yes ;)

But, just like making a game engine, there are a huge number of parts to making your game. If it's a weekend project, you can patch it up with 3rd party integrations and focus on the parts that are currently great.

jamadazi5• 5 years ago

Bevy has no stability guarantees. APIs will be broken.

However, that said, many of us are already building "real games" with Bevy. I've been using bevy almost since day-1, and none of the updates have been particularly difficult/painful. The changes have always been easy to adapt to, especially with the Rust compiler helpfully pointing out everything you need to fix ;).

In terms of features for building "real games", bevy is still lacking in many areas:

- UI is very primitive (this is the next focus area to be worked on)

- animation (already in progress)

- audio (community-made plugins are available)

- advanced rendering features and performance optimizations (also already being worked on)

- there is no editor yet

Given the super active development pace of Bevy, many of these areas will greatly improve soon.

If you want to make a content-focused game with lots of assets and requiring a level/scene editor, Bevy is not ready yet. However, if your game is more code/programming/logic heavy, I definitely recommend that you try Bevy already now. The programming experience is awesome, the ECS ergonomics are really good. It's really easy to code game logic.

setr• 5 years ago

With the implementation of Change Detection + Sparse sets, does that mean that using components to handle entity state (e.g. flags like is_hungry) is recommended? And then a system querying for Changed<is_hungry>

With archetypes alone, I believe this would have been highly undesirable (causing the entity moving back and forth between archetype tables)

TheRawMeatball4• 5 years ago

Yes! Marker components, as we like to call them are a common and encouraged pattern :)

alice-i-cecile11• 5 years ago

Yep, marker components is a much more feasible pattern now, and I tend to prefer tiny, granular components when writing Bevy apps as a result.

The only drawback to this design is that you can't add / remove components instantly[0], and instead need to wait for the next "hard sync point" at the end of the stage.

0: https://github.com/bevyengine/bevy/issues/1613

ibdknox• 5 years ago

You mention:

    The solution is to build a "graph" of archetypes to cache these results... If ComponentIds are densely packed, you can use sparse sets to cheaply jump between archetypes.

I couldn't quite figure out from the description how the edges are actually stored and I was curious why having the ComponentIds densely packed helps. I'd love to hear more about how the graph is represented. :)

_cart3• 5 years ago

We ended up cutting some of the technical ECS details from the blog post to make it more easily-digestible. The description in this pull request is effectively a stand-alone blog post describing things like the Archetype Graph: https://github.com/bevyengine/bevy/pull/1525

terafo• 5 years ago

Are there any benchmarks of Bevy ECS v2?

alice-i-cecile11• 5 years ago

There are some in the blog post, with more details in the corresponding PR: https://github.com/bevyengine/bevy/pull/1525

Ctrl+F for "Benchmarks" to find the right section :) Eventually it would be nice to update the cross-engine ecs_bench_suite fully to reflect the changes.

1-6• 5 years ago

It's easy to market what Bevy is when it's called a 'Game Engine' but I hope this platform can really become the next Omniverse-type collaborative 3D environment for the Architecture/Engineering/Construction market. Right now, there isn't a great place to park BIM files.

alice-i-cecile11• 5 years ago

Yeah, there's been a ton of interest in using Bevy for non-game applications.

We have at least two projects doing CAD with it, several trying to use it for machine learning, exotic high-performance database-like applications, and some interest in using it as an ergonomic fully cross-platform GUI builder once our UI solution is built out.

adamnemecek• 5 years ago

Can you link the CAD projects?

aimor• 5 years ago

I've been anticipating this, glad it's released! I started using Bevy a few months ago on version 0.4 and have had a really great experience learning the tool and getting help from the community. The documentation isn't as full as I'd like, but there's lots of examples and people available to answer questions. This post is just to encourage anyone interested to go ahead and try it out.

TheRawMeatball4• 5 years ago

Check out https://bevy-cheatbook.github.io/ ! It's a WIP, but it covers all the basics very well.

jamadazi5• 5 years ago

For anyone interested in learning / trying out Bevy, have a look at The Unofficial Bevy Cheatbook (i'm the author): https://bevy-cheatbook.github.io.

I did a major overhaul of the book for the new 0.5 release, and it's better than ever! Many pages were expanded or rewritten, new content added, and community feedback addressed. This is now one of the most detailed learning resources for Bevy.

Enjoy, and have fun making things with Bevy!

(the book is a continuous work in progress, even more content and improvements coming soon!)

argv_empty• 5 years ago

What does it mean for a game engine to be data oriented or data-driven?

brundolf• 5 years ago

Broadly it means there's an emphasis on creating your content declaratively, often in a config file format (i.e., not in code). Saying "there's an entity X, it has these behaviors, it has these properties" in XML or JSON or whatever else. And then actual code is written separately, to handle specific logic that uses those declarative properties.

I'm sure somebody else can give a more precise definition

Narishma• 5 years ago

I think what you describe is "data-driven". This engine is "data-oriented", which is a different thing.

jamadazi5• 5 years ago

It's in contrast to Object-Oriented Programming. In OOP, you define classes of objects, with behaviors/functionality attached to them.

In Bevy, the focus is on the data. The ECS is like a big table (if you are not familiar, you can think of it by analogy with a database or spreadsheet). It stores all your data. Components are like the columns of the table, and entities are like rows.

You then write functionality separately. You can query the ECS to get the data you need. Your logic is not attached to any particular "object instance" or "object type".

sylvain_kerkour• 5 years ago

Congrats!

For people (like me) who want to see what can be made with bevy, have a look here: https://github.com/bevyengine/awesome-bevy

dang• 5 years ago

Bevy 0.4: data oriented game engine built in Rust - https://news.ycombinator.com/item?id=25480321 - Dec 2020 (23 comments)

Bevy 0.3: game engine built in Rust - https://news.ycombinator.com/item?id=24983956 - Nov 2020 (55 comments)

Bevy 0.2 - https://news.ycombinator.com/item?id=24530698 - Sept 2020 (43 comments)

Bevy: A Game Engine in Rust - https://news.ycombinator.com/item?id=24334307 - Aug 2020 (42 comments)

Bevy: A data-driven game engine and app framework built in Rust - https://news.ycombinator.com/item?id=24123283 - Aug 2020 (103 comments)

yagizdegirmenci• 5 years ago

Bevy: A Game engine built in Rust - https://news.ycombinator.com/item?id=26131350 - February 2021 (117 comments)

reitzensteinm• 5 years ago

The activity on this story seems to have triggered the flamewar protection mechanism - any chance of vouching for it to get it back on the front page?

gwittel• 5 years ago

If you can't get to the bevyengine.org web site, you can view the release announcement in the Bevy projects' web site Github repo:

https://github.com/bevyengine/bevy-website/blob/master/conte...

kgeist• 5 years ago

Their ECS implementation sounds like a full-fledged in-memory DB.

Have there been serious attempts to use ECS outside of gamedev? The concepts are pretty interesting.

alice-i-cecile11• 5 years ago

You're not alone: the Bevy community's been exploring this too, both on the application side and the ECS-innovation side. The query caching is a neat trick that learns directly from DB's.

Some of our most anticipated planned ECS features include secondary indexes (for things like looking up all entities in a particular cell) and relations (components that also point to another entity, inspired by FLECS[0]).

0: https://ajmmertens.medium.com/flecs-v2-3-and-v2-2-is-out-893...

epage• 5 years ago

That was the eye opener to me to understanding ECS and how to apply it, that Entities are just Primary Keys and Components are Tables in a database, just in-memory and with native types. Systems are just processing stages in attaching a feedback loop to the database

Bevy 0.5: data oriented game engine built in Rust

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