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bevy/examples/3d/parenting.rs

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//! Illustrates how to create parent-child relationships between entities and how parent transforms
//! are propagated to their descendants.
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use bevy::prelude::*;
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_systems(Startup, setup)
.add_systems(Update, rotator_system)
.run();
}
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/// this component indicates what entities should rotate
#[derive(Component)]
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struct Rotator;
/// rotates the parent, which will result in the child also rotating
fn rotator_system(time: Res<Time>, mut query: Query<&mut Transform, With<Rotator>>) {
for mut transform in &mut query {
transform.rotate_x(3.0 * time.delta_secs());
}
}
/// set up a simple scene with a "parent" cube and a "child" cube
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fn setup(
Bevy ECS V2 (#1525) # Bevy ECS V2 This is a rewrite of Bevy ECS (basically everything but the new executor/schedule, which are already awesome). The overall goal was to improve the performance and versatility of Bevy ECS. Here is a quick bulleted list of changes before we dive into the details: * Complete World rewrite * Multiple component storage types: * Tables: fast cache friendly iteration, slower add/removes (previously called Archetypes) * Sparse Sets: fast add/remove, slower iteration * Stateful Queries (caches query results for faster iteration. fragmented iteration is _fast_ now) * Stateful System Params (caches expensive operations. inspired by @DJMcNab's work in #1364) * Configurable System Params (users can set configuration when they construct their systems. once again inspired by @DJMcNab's work) * Archetypes are now "just metadata", component storage is separate * Archetype Graph (for faster archetype changes) * Component Metadata * Configure component storage type * Retrieve information about component size/type/name/layout/send-ness/etc * Components are uniquely identified by a densely packed ComponentId * TypeIds are now totally optional (which should make implementing scripting easier) * Super fast "for_each" query iterators * Merged Resources into World. Resources are now just a special type of component * EntityRef/EntityMut builder apis (more efficient and more ergonomic) * Fast bitset-backed `Access<T>` replaces old hashmap-based approach everywhere * Query conflicts are determined by component access instead of archetype component access (to avoid random failures at runtime) * With/Without are still taken into account for conflicts, so this should still be comfy to use * Much simpler `IntoSystem` impl * Significantly reduced the amount of hashing throughout the ecs in favor of Sparse Sets (indexed by densely packed ArchetypeId, ComponentId, BundleId, and TableId) * Safety Improvements * Entity reservation uses a normal world reference instead of unsafe transmute * QuerySets no longer transmute lifetimes * Made traits "unsafe" where relevant * More thorough safety docs * WorldCell * Exposes safe mutable access to multiple resources at a time in a World * Replaced "catch all" `System::update_archetypes(world: &World)` with `System::new_archetype(archetype: &Archetype)` * Simpler Bundle implementation * Replaced slow "remove_bundle_one_by_one" used as fallback for Commands::remove_bundle with fast "remove_bundle_intersection" * Removed `Mut<T>` query impl. it is better to only support one way: `&mut T` * Removed with() from `Flags<T>` in favor of `Option<Flags<T>>`, which allows querying for flags to be "filtered" by default * Components now have is_send property (currently only resources support non-send) * More granular module organization * New `RemovedComponents<T>` SystemParam that replaces `query.removed::<T>()` * `world.resource_scope()` for mutable access to resources and world at the same time * WorldQuery and QueryFilter traits unified. FilterFetch trait added to enable "short circuit" filtering. Auto impled for cases that don't need it * Significantly slimmed down SystemState in favor of individual SystemParam state * System Commands changed from `commands: &mut Commands` back to `mut commands: Commands` (to allow Commands to have a World reference) Fixes #1320 ## `World` Rewrite This is a from-scratch rewrite of `World` that fills the niche that `hecs` used to. Yes, this means Bevy ECS is no longer a "fork" of hecs. We're going out our own! (the only shared code between the projects is the entity id allocator, which is already basically ideal) A huge shout out to @SanderMertens (author of [flecs](https://github.com/SanderMertens/flecs)) for sharing some great ideas with me (specifically hybrid ecs storage and archetype graphs). He also helped advise on a number of implementation details. ## Component Storage (The Problem) Two ECS storage paradigms have gained a lot of traction over the years: * **Archetypal ECS**: * Stores components in "tables" with static schemas. Each "column" stores components of a given type. Each "row" is an entity. * Each "archetype" has its own table. Adding/removing an entity's component changes the archetype. * Enables super-fast Query iteration due to its cache-friendly data layout * Comes at the cost of more expensive add/remove operations for an Entity's components, because all components need to be copied to the new archetype's "table" * **Sparse Set ECS**: * Stores components of the same type in densely packed arrays, which are sparsely indexed by densely packed unsigned integers (Entity ids) * Query iteration is slower than Archetypal ECS because each entity's component could be at any position in the sparse set. This "random access" pattern isn't cache friendly. Additionally, there is an extra layer of indirection because you must first map the entity id to an index in the component array. * Adding/removing components is a cheap, constant time operation Bevy ECS V1, hecs, legion, flec, and Unity DOTS are all "archetypal ecs-es". I personally think "archetypal" storage is a good default for game engines. An entity's archetype doesn't need to change frequently in general, and it creates "fast by default" query iteration (which is a much more common operation). It is also "self optimizing". Users don't need to think about optimizing component layouts for iteration performance. It "just works" without any extra boilerplate. Shipyard and EnTT are "sparse set ecs-es". They employ "packing" as a way to work around the "suboptimal by default" iteration performance for specific sets of components. This helps, but I didn't think this was a good choice for a general purpose engine like Bevy because: 1. "packs" conflict with each other. If bevy decides to internally pack the Transform and GlobalTransform components, users are then blocked if they want to pack some custom component with Transform. 2. users need to take manual action to optimize Developers selecting an ECS framework are stuck with a hard choice. Select an "archetypal" framework with "fast iteration everywhere" but without the ability to cheaply add/remove components, or select a "sparse set" framework to cheaply add/remove components but with slower iteration performance. ## Hybrid Component Storage (The Solution) In Bevy ECS V2, we get to have our cake and eat it too. It now has _both_ of the component storage types above (and more can be added later if needed): * **Tables** (aka "archetypal" storage) * The default storage. If you don't configure anything, this is what you get * Fast iteration by default * Slower add/remove operations * **Sparse Sets** * Opt-in * Slower iteration * Faster add/remove operations These storage types complement each other perfectly. By default Query iteration is fast. If developers know that they want to add/remove a component at high frequencies, they can set the storage to "sparse set": ```rust world.register_component( ComponentDescriptor::new::<MyComponent>(StorageType::SparseSet) ).unwrap(); ``` ## Archetypes Archetypes are now "just metadata" ... they no longer store components directly. They do store: * The `ComponentId`s of each of the Archetype's components (and that component's storage type) * Archetypes are uniquely defined by their component layouts * For example: entities with "table" components `[A, B, C]` _and_ "sparse set" components `[D, E]` will always be in the same archetype. * The `TableId` associated with the archetype * For now each archetype has exactly one table (which can have no components), * There is a 1->Many relationship from Tables->Archetypes. A given table could have any number of archetype components stored in it: * Ex: an entity with "table storage" components `[A, B, C]` and "sparse set" components `[D, E]` will share the same `[A, B, C]` table as an entity with `[A, B, C]` table component and `[F]` sparse set components. * This 1->Many relationship is how we preserve fast "cache friendly" iteration performance when possible (more on this later) * A list of entities that are in the archetype and the row id of the table they are in * ArchetypeComponentIds * unique densely packed identifiers for (ArchetypeId, ComponentId) pairs * used by the schedule executor for cheap system access control * "Archetype Graph Edges" (see the next section) ## The "Archetype Graph" Archetype changes in Bevy (and a number of other archetypal ecs-es) have historically been expensive to compute. First, you need to allocate a new vector of the entity's current component ids, add or remove components based on the operation performed, sort it (to ensure it is order-independent), then hash it to find the archetype (if it exists). And thats all before we get to the _already_ expensive full copy of all components to the new table storage. The solution is to build a "graph" of archetypes to cache these results. @SanderMertens first exposed me to the idea (and he got it from @gjroelofs, who came up with it). They propose adding directed edges between archetypes for add/remove component operations. If `ComponentId`s are densely packed, you can use sparse sets to cheaply jump between archetypes. Bevy takes this one step further by using add/remove `Bundle` edges instead of `Component` edges. Bevy encourages the use of `Bundles` to group add/remove operations. This is largely for "clearer game logic" reasons, but it also helps cut down on the number of archetype changes required. `Bundles` now also have densely-packed `BundleId`s. This allows us to use a _single_ edge for each bundle operation (rather than needing to traverse N edges ... one for each component). Single component operations are also bundles, so this is strictly an improvement over a "component only" graph. As a result, an operation that used to be _heavy_ (both for allocations and compute) is now two dirt-cheap array lookups and zero allocations. ## Stateful Queries World queries are now stateful. This allows us to: 1. Cache archetype (and table) matches * This resolves another issue with (naive) archetypal ECS: query performance getting worse as the number of archetypes goes up (and fragmentation occurs). 2. Cache Fetch and Filter state * The expensive parts of fetch/filter operations (such as hashing the TypeId to find the ComponentId) now only happen once when the Query is first constructed 3. Incrementally build up state * When new archetypes are added, we only process the new archetypes (no need to rebuild state for old archetypes) As a result, the direct `World` query api now looks like this: ```rust let mut query = world.query::<(&A, &mut B)>(); for (a, mut b) in query.iter_mut(&mut world) { } ``` Requiring `World` to generate stateful queries (rather than letting the `QueryState` type be constructed separately) allows us to ensure that _all_ queries are properly initialized (and the relevant world state, such as ComponentIds). This enables QueryState to remove branches from its operations that check for initialization status (and also enables query.iter() to take an immutable world reference because it doesn't need to initialize anything in world). However in systems, this is a non-breaking change. State management is done internally by the relevant SystemParam. ## Stateful SystemParams Like Queries, `SystemParams` now also cache state. For example, `Query` system params store the "stateful query" state mentioned above. Commands store their internal `CommandQueue`. This means you can now safely use as many separate `Commands` parameters in your system as you want. `Local<T>` system params store their `T` value in their state (instead of in Resources). SystemParam state also enabled a significant slim-down of SystemState. It is much nicer to look at now. Per-SystemParam state naturally insulates us from an "aliased mut" class of errors we have hit in the past (ex: using multiple `Commands` system params). (credit goes to @DJMcNab for the initial idea and draft pr here #1364) ## Configurable SystemParams @DJMcNab also had the great idea to make SystemParams configurable. This allows users to provide some initial configuration / values for system parameters (when possible). Most SystemParams have no config (the config type is `()`), but the `Local<T>` param now supports user-provided parameters: ```rust fn foo(value: Local<usize>) { } app.add_system(foo.system().config(|c| c.0 = Some(10))); ``` ## Uber Fast "for_each" Query Iterators Developers now have the choice to use a fast "for_each" iterator, which yields ~1.5-3x iteration speed improvements for "fragmented iteration", and minor ~1.2x iteration speed improvements for unfragmented iteration. ```rust fn system(query: Query<(&A, &mut B)>) { // you now have the option to do this for a speed boost query.for_each_mut(|(a, mut b)| { }); // however normal iterators are still available for (a, mut b) in query.iter_mut() { } } ``` I think in most cases we should continue to encourage "normal" iterators as they are more flexible and more "rust idiomatic". But when that extra "oomf" is needed, it makes sense to use `for_each`. We should also consider using `for_each` for internal bevy systems to give our users a nice speed boost (but that should be a separate pr). ## Component Metadata `World` now has a `Components` collection, which is accessible via `world.components()`. This stores mappings from `ComponentId` to `ComponentInfo`, as well as `TypeId` to `ComponentId` mappings (where relevant). `ComponentInfo` stores information about the component, such as ComponentId, TypeId, memory layout, send-ness (currently limited to resources), and storage type. ## Significantly Cheaper `Access<T>` We used to use `TypeAccess<TypeId>` to manage read/write component/archetype-component access. This was expensive because TypeIds must be hashed and compared individually. The parallel executor got around this by "condensing" type ids into bitset-backed access types. This worked, but it had to be re-generated from the `TypeAccess<TypeId>`sources every time archetypes changed. This pr removes TypeAccess in favor of faster bitset access everywhere. We can do this thanks to the move to densely packed `ComponentId`s and `ArchetypeComponentId`s. ## Merged Resources into World Resources had a lot of redundant functionality with Components. They stored typed data, they had access control, they had unique ids, they were queryable via SystemParams, etc. In fact the _only_ major difference between them was that they were unique (and didn't correlate to an entity). Separate resources also had the downside of requiring a separate set of access controls, which meant the parallel executor needed to compare more bitsets per system and manage more state. I initially got the "separate resources" idea from `legion`. I think that design was motivated by the fact that it made the direct world query/resource lifetime interactions more manageable. It certainly made our lives easier when using Resources alongside hecs/bevy_ecs. However we already have a construct for safely and ergonomically managing in-world lifetimes: systems (which use `Access<T>` internally). This pr merges Resources into World: ```rust world.insert_resource(1); world.insert_resource(2.0); let a = world.get_resource::<i32>().unwrap(); let mut b = world.get_resource_mut::<f64>().unwrap(); *b = 3.0; ``` Resources are now just a special kind of component. They have their own ComponentIds (and their own resource TypeId->ComponentId scope, so they don't conflict wit components of the same type). They are stored in a special "resource archetype", which stores components inside the archetype using a new `unique_components` sparse set (note that this sparse set could later be used to implement Tags). This allows us to keep the code size small by reusing existing datastructures (namely Column, Archetype, ComponentFlags, and ComponentInfo). This allows us the executor to use a single `Access<ArchetypeComponentId>` per system. It should also make scripting language integration easier. _But_ this merge did create problems for people directly interacting with `World`. What if you need mutable access to multiple resources at the same time? `world.get_resource_mut()` borrows World mutably! ## WorldCell WorldCell applies the `Access<ArchetypeComponentId>` concept to direct world access: ```rust let world_cell = world.cell(); let a = world_cell.get_resource_mut::<i32>().unwrap(); let b = world_cell.get_resource_mut::<f64>().unwrap(); ``` This adds cheap runtime checks (a sparse set lookup of `ArchetypeComponentId` and a counter) to ensure that world accesses do not conflict with each other. Each operation returns a `WorldBorrow<'w, T>` or `WorldBorrowMut<'w, T>` wrapper type, which will release the relevant ArchetypeComponentId resources when dropped. World caches the access sparse set (and only one cell can exist at a time), so `world.cell()` is a cheap operation. WorldCell does _not_ use atomic operations. It is non-send, does a mutable borrow of world to prevent other accesses, and uses a simple `Rc<RefCell<ArchetypeComponentAccess>>` wrapper in each WorldBorrow pointer. The api is currently limited to resource access, but it can and should be extended to queries / entity component access. ## Resource Scopes WorldCell does not yet support component queries, and even when it does there are sometimes legitimate reasons to want a mutable world ref _and_ a mutable resource ref (ex: bevy_render and bevy_scene both need this). In these cases we could always drop down to the unsafe `world.get_resource_unchecked_mut()`, but that is not ideal! Instead developers can use a "resource scope" ```rust world.resource_scope(|world: &mut World, a: &mut A| { }) ``` This temporarily removes the `A` resource from `World`, provides mutable pointers to both, and re-adds A to World when finished. Thanks to the move to ComponentIds/sparse sets, this is a cheap operation. If multiple resources are required, scopes can be nested. We could also consider adding a "resource tuple" to the api if this pattern becomes common and the boilerplate gets nasty. ## Query Conflicts Use ComponentId Instead of ArchetypeComponentId For safety reasons, systems cannot contain queries that conflict with each other without wrapping them in a QuerySet. On bevy `main`, we use ArchetypeComponentIds to determine conflicts. This is nice because it can take into account filters: ```rust // these queries will never conflict due to their filters fn filter_system(a: Query<&mut A, With<B>>, b: Query<&mut B, Without<B>>) { } ``` But it also has a significant downside: ```rust // these queries will not conflict _until_ an entity with A, B, and C is spawned fn maybe_conflicts_system(a: Query<(&mut A, &C)>, b: Query<(&mut A, &B)>) { } ``` The system above will panic at runtime if an entity with A, B, and C is spawned. This makes it hard to trust that your game logic will run without crashing. In this pr, I switched to using `ComponentId` instead. This _is_ more constraining. `maybe_conflicts_system` will now always fail, but it will do it consistently at startup. Naively, it would also _disallow_ `filter_system`, which would be a significant downgrade in usability. Bevy has a number of internal systems that rely on disjoint queries and I expect it to be a common pattern in userspace. To resolve this, I added a new `FilteredAccess<T>` type, which wraps `Access<T>` and adds with/without filters. If two `FilteredAccess` have with/without values that prove they are disjoint, they will no longer conflict. ## EntityRef / EntityMut World entity operations on `main` require that the user passes in an `entity` id to each operation: ```rust let entity = world.spawn((A, )); // create a new entity with A world.get::<A>(entity); world.insert(entity, (B, C)); world.insert_one(entity, D); ``` This means that each operation needs to look up the entity location / verify its validity. The initial spawn operation also requires a Bundle as input. This can be awkward when no components are required (or one component is required). These operations have been replaced by `EntityRef` and `EntityMut`, which are "builder-style" wrappers around world that provide read and read/write operations on a single, pre-validated entity: ```rust // spawn now takes no inputs and returns an EntityMut let entity = world.spawn() .insert(A) // insert a single component into the entity .insert_bundle((B, C)) // insert a bundle of components into the entity .id() // id returns the Entity id // Returns EntityMut (or panics if the entity does not exist) world.entity_mut(entity) .insert(D) .insert_bundle(SomeBundle::default()); { // returns EntityRef (or panics if the entity does not exist) let d = world.entity(entity) .get::<D>() // gets the D component .unwrap(); // world.get still exists for ergonomics let d = world.get::<D>(entity).unwrap(); } // These variants return Options if you want to check existence instead of panicing world.get_entity_mut(entity) .unwrap() .insert(E); if let Some(entity_ref) = world.get_entity(entity) { let d = entity_ref.get::<D>().unwrap(); } ``` This _does not_ affect the current Commands api or terminology. I think that should be a separate conversation as that is a much larger breaking change. ## Safety Improvements * Entity reservation in Commands uses a normal world borrow instead of an unsafe transmute * QuerySets no longer transmutes lifetimes * Made traits "unsafe" when implementing a trait incorrectly could cause unsafety * More thorough safety docs ## RemovedComponents SystemParam The old approach to querying removed components: `query.removed:<T>()` was confusing because it had no connection to the query itself. I replaced it with the following, which is both clearer and allows us to cache the ComponentId mapping in the SystemParamState: ```rust fn system(removed: RemovedComponents<T>) { for entity in removed.iter() { } } ``` ## Simpler Bundle implementation Bundles are no longer responsible for sorting (or deduping) TypeInfo. They are just a simple ordered list of component types / data. This makes the implementation smaller and opens the door to an easy "nested bundle" implementation in the future (which i might even add in this pr). Duplicate detection is now done once per bundle type by World the first time a bundle is used. ## Unified WorldQuery and QueryFilter types (don't worry they are still separate type _parameters_ in Queries .. this is a non-breaking change) WorldQuery and QueryFilter were already basically identical apis. With the addition of `FetchState` and more storage-specific fetch methods, the overlap was even clearer (and the redundancy more painful). QueryFilters are now just `F: WorldQuery where F::Fetch: FilterFetch`. FilterFetch requires `Fetch<Item = bool>` and adds new "short circuit" variants of fetch methods. This enables a filter tuple like `(With<A>, Without<B>, Changed<C>)` to stop evaluating the filter after the first mismatch is encountered. FilterFetch is automatically implemented for `Fetch` implementations that return bool. This forces fetch implementations that return things like `(bool, bool, bool)` (such as the filter above) to manually implement FilterFetch and decide whether or not to short-circuit. ## More Granular Modules World no longer globs all of the internal modules together. It now exports `core`, `system`, and `schedule` separately. I'm also considering exporting `core` submodules directly as that is still pretty "glob-ey" and unorganized (feedback welcome here). ## Remaining Draft Work (to be done in this pr) * ~~panic on conflicting WorldQuery fetches (&A, &mut A)~~ * ~~bevy `main` and hecs both currently allow this, but we should protect against it if possible~~ * ~~batch_iter / par_iter (currently stubbed out)~~ * ~~ChangedRes~~ * ~~I skipped this while we sort out #1313. This pr should be adapted to account for whatever we land on there~~. * ~~The `Archetypes` and `Tables` collections use hashes of sorted lists of component ids to uniquely identify each archetype/table. This hash is then used as the key in a HashMap to look up the relevant ArchetypeId or TableId. (which doesn't handle hash collisions properly)~~ * ~~It is currently unsafe to generate a Query from "World A", then use it on "World B" (despite the api claiming it is safe). We should probably close this gap. This could be done by adding a randomly generated WorldId to each world, then storing that id in each Query. They could then be compared to each other on each `query.do_thing(&world)` operation. This _does_ add an extra branch to each query operation, so I'm open to other suggestions if people have them.~~ * ~~Nested Bundles (if i find time)~~ ## Potential Future Work * Expand WorldCell to support queries. * Consider not allocating in the empty archetype on `world.spawn()` * ex: return something like EntityMutUninit, which turns into EntityMut after an `insert` or `insert_bundle` op * this actually regressed performance last time i tried it, but in theory it should be faster * Optimize SparseSet::insert (see `PERF` comment on insert) * Replace SparseArray `Option<T>` with T::MAX to cut down on branching * would enable cheaper get_unchecked() operations * upstream fixedbitset optimizations * fixedbitset could be allocation free for small block counts (store blocks in a SmallVec) * fixedbitset could have a const constructor * Consider implementing Tags (archetype-specific by-value data that affects archetype identity) * ex: ArchetypeA could have `[A, B, C]` table components and `[D(1)]` "tag" component. ArchetypeB could have `[A, B, C]` table components and a `[D(2)]` tag component. The archetypes are different, despite both having D tags because the value inside D is different. * this could potentially build on top of the `archetype.unique_components` added in this pr for resource storage. * Consider reverting `all_tuples` proc macro in favor of the old `macro_rules` implementation * all_tuples is more flexible and produces cleaner documentation (the macro_rules version produces weird type parameter orders due to parser constraints) * but unfortunately all_tuples also appears to make Rust Analyzer sad/slow when working inside of `bevy_ecs` (does not affect user code) * Consider "resource queries" and/or "mixed resource and entity component queries" as an alternative to WorldCell * this is basically just "systems" so maybe it's not worth it * Add more world ops * `world.clear()` * `world.reserve<T: Bundle>(count: usize)` * Try using the old archetype allocation strategy (allocate new memory on resize and copy everything over). I expect this to improve batch insertion performance at the cost of unbatched performance. But thats just a guess. I'm not an allocation perf pro :) * Adapt Commands apis for consistency with new World apis ## Benchmarks key: * `bevy_old`: bevy `main` branch * `bevy`: this branch * `_foreach`: uses an optimized for_each iterator * ` _sparse`: uses sparse set storage (if unspecified assume table storage) * `_system`: runs inside a system (if unspecified assume test happens via direct world ops) ### Simple Insert (from ecs_bench_suite) ![image](https://user-images.githubusercontent.com/2694663/109245573-9c3ce100-7795-11eb-9003-bfd41cd5c51f.png) ### Simpler Iter (from ecs_bench_suite) ![image](https://user-images.githubusercontent.com/2694663/109245795-ffc70e80-7795-11eb-92fb-3ffad09aabf7.png) ### Fragment Iter (from ecs_bench_suite) ![image](https://user-images.githubusercontent.com/2694663/109245849-0fdeee00-7796-11eb-8d25-eb6b7a682c48.png) ### Sparse Fragmented Iter Iterate a query that matches 5 entities from a single matching archetype, but there are 100 unmatching archetypes ![image](https://user-images.githubusercontent.com/2694663/109245916-2b49f900-7796-11eb-9a8f-ed89c203f940.png) ### Schedule (from ecs_bench_suite) ![image](https://user-images.githubusercontent.com/2694663/109246428-1fab0200-7797-11eb-8841-1b2161e90fa4.png) ### Add Remove Component (from ecs_bench_suite) ![image](https://user-images.githubusercontent.com/2694663/109246492-39e4e000-7797-11eb-8985-2706bd0495ab.png) ### Add Remove Component Big Same as the test above, but each entity has 5 "large" matrix components and 1 "large" matrix component is added and removed ![image](https://user-images.githubusercontent.com/2694663/109246517-449f7500-7797-11eb-835e-28b6790daeaa.png) ### Get Component Looks up a single component value a large number of times ![image](https://user-images.githubusercontent.com/2694663/109246129-87ad1880-7796-11eb-9fcb-c38012aa7c70.png)
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mut commands: Commands,
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mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<StandardMaterial>>,
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) {
Deprecate shapes in `bevy_render::mesh::shape` (#11773) # Objective #11431 and #11688 implemented meshing support for Bevy's new geometric primitives. The next step is to deprecate the shapes in `bevy_render::mesh::shape` and to later remove them completely for 0.14. ## Solution Deprecate the shapes and reduce code duplication by utilizing the primitive meshing API for the old shapes where possible. Note that some shapes have behavior that can't be exactly reproduced with the new primitives yet: - `Box` is more of an AABB with min/max extents - `Plane` supports a subdivision count - `Quad` has a `flipped` property These types have not been changed to utilize the new primitives yet. --- ## Changelog - Deprecated all shapes in `bevy_render::mesh::shape` - Changed all examples to use new primitives for meshing ## Migration Guide Bevy has previously used rendering-specific types like `UVSphere` and `Quad` for primitive mesh shapes. These have now been deprecated to use the geometric primitives newly introduced in version 0.13. Some examples: ```rust let before = meshes.add(shape::Box::new(5.0, 0.15, 5.0)); let after = meshes.add(Cuboid::new(5.0, 0.15, 5.0)); let before = meshes.add(shape::Quad::default()); let after = meshes.add(Rectangle::default()); let before = meshes.add(shape::Plane::from_size(5.0)); // The surface normal can now also be specified when using `new` let after = meshes.add(Plane3d::default().mesh().size(5.0, 5.0)); let before = meshes.add( Mesh::try_from(shape::Icosphere { radius: 0.5, subdivisions: 5, }) .unwrap(), ); let after = meshes.add(Sphere::new(0.5).mesh().ico(5).unwrap()); ```
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let cube_handle = meshes.add(Cuboid::new(2.0, 2.0, 2.0));
2020-05-14 00:31:56 +00:00
let cube_material_handle = materials.add(StandardMaterial {
Migrate from `LegacyColor` to `bevy_color::Color` (#12163) # Objective - As part of the migration process we need to a) see the end effect of the migration on user ergonomics b) check for serious perf regressions c) actually migrate the code - To accomplish this, I'm going to attempt to migrate all of the remaining user-facing usages of `LegacyColor` in one PR, being careful to keep a clean commit history. - Fixes #12056. ## Solution I've chosen to use the polymorphic `Color` type as our standard user-facing API. - [x] Migrate `bevy_gizmos`. - [x] Take `impl Into<Color>` in all `bevy_gizmos` APIs - [x] Migrate sprites - [x] Migrate UI - [x] Migrate `ColorMaterial` - [x] Migrate `MaterialMesh2D` - [x] Migrate fog - [x] Migrate lights - [x] Migrate StandardMaterial - [x] Migrate wireframes - [x] Migrate clear color - [x] Migrate text - [x] Migrate gltf loader - [x] Register color types for reflection - [x] Remove `LegacyColor` - [x] Make sure CI passes Incidental improvements to ease migration: - added `Color::srgba_u8`, `Color::srgba_from_array` and friends - added `set_alpha`, `is_fully_transparent` and `is_fully_opaque` to the `Alpha` trait - add and immediately deprecate (lol) `Color::rgb` and friends in favor of more explicit and consistent `Color::srgb` - standardized on white and black for most example text colors - added vector field traits to `LinearRgba`: ~~`Add`, `Sub`, `AddAssign`, `SubAssign`,~~ `Mul<f32>` and `Div<f32>`. Multiplications and divisions do not scale alpha. `Add` and `Sub` have been cut from this PR. - added `LinearRgba` and `Srgba` `RED/GREEN/BLUE` - added `LinearRgba_to_f32_array` and `LinearRgba::to_u32` ## Migration Guide Bevy's color types have changed! Wherever you used a `bevy::render::Color`, a `bevy::color::Color` is used instead. These are quite similar! Both are enums storing a color in a specific color space (or to be more precise, using a specific color model). However, each of the different color models now has its own type. TODO... - `Color::rgba`, `Color::rgb`, `Color::rbga_u8`, `Color::rgb_u8`, `Color::rgb_from_array` are now `Color::srgba`, `Color::srgb`, `Color::srgba_u8`, `Color::srgb_u8` and `Color::srgb_from_array`. - `Color::set_a` and `Color::a` is now `Color::set_alpha` and `Color::alpha`. These are part of the `Alpha` trait in `bevy_color`. - `Color::is_fully_transparent` is now part of the `Alpha` trait in `bevy_color` - `Color::r`, `Color::set_r`, `Color::with_r` and the equivalents for `g`, `b` `h`, `s` and `l` have been removed due to causing silent relatively expensive conversions. Convert your `Color` into the desired color space, perform your operations there, and then convert it back into a polymorphic `Color` enum. - `Color::hex` is now `Srgba::hex`. Call `.into` or construct a `Color::Srgba` variant manually to convert it. - `WireframeMaterial`, `ExtractedUiNode`, `ExtractedDirectionalLight`, `ExtractedPointLight`, `ExtractedSpotLight` and `ExtractedSprite` now store a `LinearRgba`, rather than a polymorphic `Color` - `Color::rgb_linear` and `Color::rgba_linear` are now `Color::linear_rgb` and `Color::linear_rgba` - The various CSS color constants are no longer stored directly on `Color`. Instead, they're defined in the `Srgba` color space, and accessed via `bevy::color::palettes::css`. Call `.into()` on them to convert them into a `Color` for quick debugging use, and consider using the much prettier `tailwind` palette for prototyping. - The `LIME_GREEN` color has been renamed to `LIMEGREEN` to comply with the standard naming. - Vector field arithmetic operations on `Color` (add, subtract, multiply and divide by a f32) have been removed. Instead, convert your colors into `LinearRgba` space, and perform your operations explicitly there. This is particularly relevant when working with emissive or HDR colors, whose color channel values are routinely outside of the ordinary 0 to 1 range. - `Color::as_linear_rgba_f32` has been removed. Call `LinearRgba::to_f32_array` instead, converting if needed. - `Color::as_linear_rgba_u32` has been removed. Call `LinearRgba::to_u32` instead, converting if needed. - Several other color conversion methods to transform LCH or HSL colors into float arrays or `Vec` types have been removed. Please reimplement these externally or open a PR to re-add them if you found them particularly useful. - Various methods on `Color` such as `rgb` or `hsl` to convert the color into a specific color space have been removed. Convert into `LinearRgba`, then to the color space of your choice. - Various implicitly-converting color value methods on `Color` such as `r`, `g`, `b` or `h` have been removed. Please convert it into the color space of your choice, then check these properties. - `Color` no longer implements `AsBindGroup`. Store a `LinearRgba` internally instead to avoid conversion costs. --------- Co-authored-by: Alice Cecile <alice.i.cecil@gmail.com> Co-authored-by: Afonso Lage <lage.afonso@gmail.com> Co-authored-by: Rob Parrett <robparrett@gmail.com> Co-authored-by: Zachary Harrold <zac@harrold.com.au>
2024-02-29 19:35:12 +00:00
base_color: Color::srgb(0.8, 0.7, 0.6),
..default()
});
// parent cube
2020-07-10 04:18:35 +00:00
commands
Spawn now takes a Bundle (#6054) # Objective Now that we can consolidate Bundles and Components under a single insert (thanks to #2975 and #6039), almost 100% of world spawns now look like `world.spawn().insert((Some, Tuple, Here))`. Spawning an entity without any components is an extremely uncommon pattern, so it makes sense to give spawn the "first class" ergonomic api. This consolidated api should be made consistent across all spawn apis (such as World and Commands). ## Solution All `spawn` apis (`World::spawn`, `Commands:;spawn`, `ChildBuilder::spawn`, and `WorldChildBuilder::spawn`) now accept a bundle as input: ```rust // before: commands .spawn() .insert((A, B, C)); world .spawn() .insert((A, B, C); // after commands.spawn((A, B, C)); world.spawn((A, B, C)); ``` All existing instances of `spawn_bundle` have been deprecated in favor of the new `spawn` api. A new `spawn_empty` has been added, replacing the old `spawn` api. By allowing `world.spawn(some_bundle)` to replace `world.spawn().insert(some_bundle)`, this opened the door to removing the initial entity allocation in the "empty" archetype / table done in `spawn()` (and subsequent move to the actual archetype in `.insert(some_bundle)`). This improves spawn performance by over 10%: ![image](https://user-images.githubusercontent.com/2694663/191627587-4ab2f949-4ccd-4231-80eb-80dd4d9ad6b9.png) To take this measurement, I added a new `world_spawn` benchmark. Unfortunately, optimizing `Commands::spawn` is slightly less trivial, as Commands expose the Entity id of spawned entities prior to actually spawning. Doing the optimization would (naively) require assurances that the `spawn(some_bundle)` command is applied before all other commands involving the entity (which would not necessarily be true, if memory serves). Optimizing `Commands::spawn` this way does feel possible, but it will require careful thought (and maybe some additional checks), which deserves its own PR. For now, it has the same performance characteristics of the current `Commands::spawn_bundle` on main. **Note that 99% of this PR is simple renames and refactors. The only code that needs careful scrutiny is the new `World::spawn()` impl, which is relatively straightforward, but it has some new unsafe code (which re-uses battle tested BundlerSpawner code path).** --- ## Changelog - All `spawn` apis (`World::spawn`, `Commands:;spawn`, `ChildBuilder::spawn`, and `WorldChildBuilder::spawn`) now accept a bundle as input - All instances of `spawn_bundle` have been deprecated in favor of the new `spawn` api - World and Commands now have `spawn_empty()`, which is equivalent to the old `spawn()` behavior. ## Migration Guide ```rust // Old (0.8): commands .spawn() .insert_bundle((A, B, C)); // New (0.9) commands.spawn((A, B, C)); // Old (0.8): commands.spawn_bundle((A, B, C)); // New (0.9) commands.spawn((A, B, C)); // Old (0.8): let entity = commands.spawn().id(); // New (0.9) let entity = commands.spawn_empty().id(); // Old (0.8) let entity = world.spawn().id(); // New (0.9) let entity = world.spawn_empty(); ```
2022-09-23 19:55:54 +00:00
.spawn((
Migrate meshes and materials to required components (#15524) # Objective A big step in the migration to required components: meshes and materials! ## Solution As per the [selected proposal](https://hackmd.io/@bevy/required_components/%2Fj9-PnF-2QKK0on1KQ29UWQ): - Deprecate `MaterialMesh2dBundle`, `MaterialMeshBundle`, and `PbrBundle`. - Add `Mesh2d` and `Mesh3d` components, which wrap a `Handle<Mesh>`. - Add `MeshMaterial2d<M: Material2d>` and `MeshMaterial3d<M: Material>`, which wrap a `Handle<M>`. - Meshes *without* a mesh material should be rendered with a default material. The existence of a material is determined by `HasMaterial2d`/`HasMaterial3d`, which is required by `MeshMaterial2d`/`MeshMaterial3d`. This gets around problems with the generics. Previously: ```rust commands.spawn(MaterialMesh2dBundle { mesh: meshes.add(Circle::new(100.0)).into(), material: materials.add(Color::srgb(7.5, 0.0, 7.5)), transform: Transform::from_translation(Vec3::new(-200., 0., 0.)), ..default() }); ``` Now: ```rust commands.spawn(( Mesh2d(meshes.add(Circle::new(100.0))), MeshMaterial2d(materials.add(Color::srgb(7.5, 0.0, 7.5))), Transform::from_translation(Vec3::new(-200., 0., 0.)), )); ``` If the mesh material is missing, previously nothing was rendered. Now, it renders a white default `ColorMaterial` in 2D and a `StandardMaterial` in 3D (this can be overridden). Below, only every other entity has a material: ![Näyttökuva 2024-09-29 181746](https://github.com/user-attachments/assets/5c8be029-d2fe-4b8c-ae89-17a72ff82c9a) ![Näyttökuva 2024-09-29 181918](https://github.com/user-attachments/assets/58adbc55-5a1e-4c7d-a2c7-ed456227b909) Why white? This is still open for discussion, but I think white makes sense for a *default* material, while *invalid* asset handles pointing to nothing should have something like a pink material to indicate that something is broken (I don't handle that in this PR yet). This is kind of a mix of Godot and Unity: Godot just renders a white material for non-existent materials, while Unity renders nothing when no materials exist, but renders pink for invalid materials. I can also change the default material to pink if that is preferable though. ## Testing I ran some 2D and 3D examples to test if anything changed visually. I have not tested all examples or features yet however. If anyone wants to test more extensively, it would be appreciated! ## Implementation Notes - The relationship between `bevy_render` and `bevy_pbr` is weird here. `bevy_render` needs `Mesh3d` for its own systems, but `bevy_pbr` has all of the material logic, and `bevy_render` doesn't depend on it. I feel like the two crates should be refactored in some way, but I think that's out of scope for this PR. - I didn't migrate meshlets to required components yet. That can probably be done in a follow-up, as this is already a huge PR. - It is becoming increasingly clear to me that we really, *really* want to disallow raw asset handles as components. They caused me a *ton* of headache here already, and it took me a long time to find every place that queried for them or inserted them directly on entities, since there were no compiler errors for it. If we don't remove the `Component` derive, I expect raw asset handles to be a *huge* footgun for users as we transition to wrapper components, especially as handles as components have been the norm so far. I personally consider this to be a blocker for 0.15: we need to migrate to wrapper components for asset handles everywhere, and remove the `Component` derive. Also see https://github.com/bevyengine/bevy/issues/14124. --- ## Migration Guide Asset handles for meshes and mesh materials must now be wrapped in the `Mesh2d` and `MeshMaterial2d` or `Mesh3d` and `MeshMaterial3d` components for 2D and 3D respectively. Raw handles as components no longer render meshes. Additionally, `MaterialMesh2dBundle`, `MaterialMeshBundle`, and `PbrBundle` have been deprecated. Instead, use the mesh and material components directly. Previously: ```rust commands.spawn(MaterialMesh2dBundle { mesh: meshes.add(Circle::new(100.0)).into(), material: materials.add(Color::srgb(7.5, 0.0, 7.5)), transform: Transform::from_translation(Vec3::new(-200., 0., 0.)), ..default() }); ``` Now: ```rust commands.spawn(( Mesh2d(meshes.add(Circle::new(100.0))), MeshMaterial2d(materials.add(Color::srgb(7.5, 0.0, 7.5))), Transform::from_translation(Vec3::new(-200., 0., 0.)), )); ``` If the mesh material is missing, a white default material is now used. Previously, nothing was rendered if the material was missing. The `WithMesh2d` and `WithMesh3d` query filter type aliases have also been removed. Simply use `With<Mesh2d>` or `With<Mesh3d>`. --------- Co-authored-by: Tim Blackbird <justthecooldude@gmail.com> Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2024-10-01 21:33:17 +00:00
Mesh3d(cube_handle.clone()),
MeshMaterial3d(cube_material_handle.clone()),
Transform::from_xyz(0.0, 0.0, 1.0),
Spawn now takes a Bundle (#6054) # Objective Now that we can consolidate Bundles and Components under a single insert (thanks to #2975 and #6039), almost 100% of world spawns now look like `world.spawn().insert((Some, Tuple, Here))`. Spawning an entity without any components is an extremely uncommon pattern, so it makes sense to give spawn the "first class" ergonomic api. This consolidated api should be made consistent across all spawn apis (such as World and Commands). ## Solution All `spawn` apis (`World::spawn`, `Commands:;spawn`, `ChildBuilder::spawn`, and `WorldChildBuilder::spawn`) now accept a bundle as input: ```rust // before: commands .spawn() .insert((A, B, C)); world .spawn() .insert((A, B, C); // after commands.spawn((A, B, C)); world.spawn((A, B, C)); ``` All existing instances of `spawn_bundle` have been deprecated in favor of the new `spawn` api. A new `spawn_empty` has been added, replacing the old `spawn` api. By allowing `world.spawn(some_bundle)` to replace `world.spawn().insert(some_bundle)`, this opened the door to removing the initial entity allocation in the "empty" archetype / table done in `spawn()` (and subsequent move to the actual archetype in `.insert(some_bundle)`). This improves spawn performance by over 10%: ![image](https://user-images.githubusercontent.com/2694663/191627587-4ab2f949-4ccd-4231-80eb-80dd4d9ad6b9.png) To take this measurement, I added a new `world_spawn` benchmark. Unfortunately, optimizing `Commands::spawn` is slightly less trivial, as Commands expose the Entity id of spawned entities prior to actually spawning. Doing the optimization would (naively) require assurances that the `spawn(some_bundle)` command is applied before all other commands involving the entity (which would not necessarily be true, if memory serves). Optimizing `Commands::spawn` this way does feel possible, but it will require careful thought (and maybe some additional checks), which deserves its own PR. For now, it has the same performance characteristics of the current `Commands::spawn_bundle` on main. **Note that 99% of this PR is simple renames and refactors. The only code that needs careful scrutiny is the new `World::spawn()` impl, which is relatively straightforward, but it has some new unsafe code (which re-uses battle tested BundlerSpawner code path).** --- ## Changelog - All `spawn` apis (`World::spawn`, `Commands:;spawn`, `ChildBuilder::spawn`, and `WorldChildBuilder::spawn`) now accept a bundle as input - All instances of `spawn_bundle` have been deprecated in favor of the new `spawn` api - World and Commands now have `spawn_empty()`, which is equivalent to the old `spawn()` behavior. ## Migration Guide ```rust // Old (0.8): commands .spawn() .insert_bundle((A, B, C)); // New (0.9) commands.spawn((A, B, C)); // Old (0.8): commands.spawn_bundle((A, B, C)); // New (0.9) commands.spawn((A, B, C)); // Old (0.8): let entity = commands.spawn().id(); // New (0.9) let entity = commands.spawn_empty().id(); // Old (0.8) let entity = world.spawn().id(); // New (0.9) let entity = world.spawn_empty(); ```
2022-09-23 19:55:54 +00:00
Rotator,
))
2020-07-10 04:18:35 +00:00
.with_children(|parent| {
// child cube
Migrate meshes and materials to required components (#15524) # Objective A big step in the migration to required components: meshes and materials! ## Solution As per the [selected proposal](https://hackmd.io/@bevy/required_components/%2Fj9-PnF-2QKK0on1KQ29UWQ): - Deprecate `MaterialMesh2dBundle`, `MaterialMeshBundle`, and `PbrBundle`. - Add `Mesh2d` and `Mesh3d` components, which wrap a `Handle<Mesh>`. - Add `MeshMaterial2d<M: Material2d>` and `MeshMaterial3d<M: Material>`, which wrap a `Handle<M>`. - Meshes *without* a mesh material should be rendered with a default material. The existence of a material is determined by `HasMaterial2d`/`HasMaterial3d`, which is required by `MeshMaterial2d`/`MeshMaterial3d`. This gets around problems with the generics. Previously: ```rust commands.spawn(MaterialMesh2dBundle { mesh: meshes.add(Circle::new(100.0)).into(), material: materials.add(Color::srgb(7.5, 0.0, 7.5)), transform: Transform::from_translation(Vec3::new(-200., 0., 0.)), ..default() }); ``` Now: ```rust commands.spawn(( Mesh2d(meshes.add(Circle::new(100.0))), MeshMaterial2d(materials.add(Color::srgb(7.5, 0.0, 7.5))), Transform::from_translation(Vec3::new(-200., 0., 0.)), )); ``` If the mesh material is missing, previously nothing was rendered. Now, it renders a white default `ColorMaterial` in 2D and a `StandardMaterial` in 3D (this can be overridden). Below, only every other entity has a material: ![Näyttökuva 2024-09-29 181746](https://github.com/user-attachments/assets/5c8be029-d2fe-4b8c-ae89-17a72ff82c9a) ![Näyttökuva 2024-09-29 181918](https://github.com/user-attachments/assets/58adbc55-5a1e-4c7d-a2c7-ed456227b909) Why white? This is still open for discussion, but I think white makes sense for a *default* material, while *invalid* asset handles pointing to nothing should have something like a pink material to indicate that something is broken (I don't handle that in this PR yet). This is kind of a mix of Godot and Unity: Godot just renders a white material for non-existent materials, while Unity renders nothing when no materials exist, but renders pink for invalid materials. I can also change the default material to pink if that is preferable though. ## Testing I ran some 2D and 3D examples to test if anything changed visually. I have not tested all examples or features yet however. If anyone wants to test more extensively, it would be appreciated! ## Implementation Notes - The relationship between `bevy_render` and `bevy_pbr` is weird here. `bevy_render` needs `Mesh3d` for its own systems, but `bevy_pbr` has all of the material logic, and `bevy_render` doesn't depend on it. I feel like the two crates should be refactored in some way, but I think that's out of scope for this PR. - I didn't migrate meshlets to required components yet. That can probably be done in a follow-up, as this is already a huge PR. - It is becoming increasingly clear to me that we really, *really* want to disallow raw asset handles as components. They caused me a *ton* of headache here already, and it took me a long time to find every place that queried for them or inserted them directly on entities, since there were no compiler errors for it. If we don't remove the `Component` derive, I expect raw asset handles to be a *huge* footgun for users as we transition to wrapper components, especially as handles as components have been the norm so far. I personally consider this to be a blocker for 0.15: we need to migrate to wrapper components for asset handles everywhere, and remove the `Component` derive. Also see https://github.com/bevyengine/bevy/issues/14124. --- ## Migration Guide Asset handles for meshes and mesh materials must now be wrapped in the `Mesh2d` and `MeshMaterial2d` or `Mesh3d` and `MeshMaterial3d` components for 2D and 3D respectively. Raw handles as components no longer render meshes. Additionally, `MaterialMesh2dBundle`, `MaterialMeshBundle`, and `PbrBundle` have been deprecated. Instead, use the mesh and material components directly. Previously: ```rust commands.spawn(MaterialMesh2dBundle { mesh: meshes.add(Circle::new(100.0)).into(), material: materials.add(Color::srgb(7.5, 0.0, 7.5)), transform: Transform::from_translation(Vec3::new(-200., 0., 0.)), ..default() }); ``` Now: ```rust commands.spawn(( Mesh2d(meshes.add(Circle::new(100.0))), MeshMaterial2d(materials.add(Color::srgb(7.5, 0.0, 7.5))), Transform::from_translation(Vec3::new(-200., 0., 0.)), )); ``` If the mesh material is missing, a white default material is now used. Previously, nothing was rendered if the material was missing. The `WithMesh2d` and `WithMesh3d` query filter type aliases have also been removed. Simply use `With<Mesh2d>` or `With<Mesh3d>`. --------- Co-authored-by: Tim Blackbird <justthecooldude@gmail.com> Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2024-10-01 21:33:17 +00:00
parent.spawn((
Mesh3d(cube_handle),
MeshMaterial3d(cube_material_handle),
Transform::from_xyz(0.0, 0.0, 3.0),
));
2020-04-07 20:25:01 +00:00
});
// light
commands.spawn((PointLight::default(), Transform::from_xyz(4.0, 5.0, -4.0)));
// camera
commands.spawn((
Camera3d::default(),
Transform::from_xyz(5.0, 10.0, 10.0).looking_at(Vec3::ZERO, Vec3::Y),
));
2020-01-11 09:59:39 +00:00
}