# Objective
Add an option to `many_buttons` that spawns a grid of buttons where each
button is rendered through its own camera.
## Testing
Run with:
```
cargo run --example many_buttons --release -- --many-cameras --buttons 20
```
The default buttons count of `110` is too much for my computer.
# Objective
As discussed in #14275, Bevy is currently too prone to panic, and makes
the easy / beginner-friendly way to do a large number of operations just
to panic on failure.
This is seriously frustrating in library code, but also slows down
development, as many of the `Query::single` panics can actually safely
be an early return (these panics are often due to a small ordering issue
or a change in game state.
More critically, in most "finished" products, panics are unacceptable:
any unexpected failures should be handled elsewhere. That's where the
new
With the advent of good system error handling, we can now remove this.
Note: I was instrumental in a) introducing this idea in the first place
and b) pushing to make the panicking variant the default. The
introduction of both `let else` statements in Rust and the fancy system
error handling work in 0.16 have changed my mind on the right balance
here.
## Solution
1. Make `Query::single` and `Query::single_mut` (and other random
related methods) return a `Result`.
2. Handle all of Bevy's internal usage of these APIs.
3. Deprecate `Query::get_single` and friends, since we've moved their
functionality to the nice names.
4. Add detailed advice on how to best handle these errors.
Generally I like the diff here, although `get_single().unwrap()` in
tests is a bit of a downgrade.
## Testing
I've done a global search for `.single` to track down any missed
deprecated usages.
As to whether or not all the migrations were successful, that's what CI
is for :)
## Future work
~~Rename `Query::get_single` and friends to `Query::single`!~~
~~I've opted not to do this in this PR, and smear it across two releases
in order to ease the migration. Successive deprecations are much easier
to manage than the semantics and types shifting under your feet.~~
Cart has convinced me to change my mind on this; see
https://github.com/bevyengine/bevy/pull/18082#discussion_r1974536085.
## Migration guide
`Query::single`, `Query::single_mut` and their `QueryState` equivalents
now return a `Result`. Generally, you'll want to:
1. Use Bevy 0.16's system error handling to return a `Result` using the
`?` operator.
2. Use a `let else Ok(data)` block to early return if it's an expected
failure.
3. Use `unwrap()` or `Ok` destructuring inside of tests.
The old `Query::get_single` (etc) methods which did this have been
deprecated.
# Objective
Implements and closes#17515
## Solution
Add `uv_transform` to `ColorMaterial`
## Testing
Create a example similar to `repeated_texture` but for `Mesh2d` and
`MeshMaterial2d<ColorMaterial>`
## Showcase

## Migration Guide
Add `uv_transform` field to constructors of `ColorMaterial`
# Objective
- Fixes#17960
## Solution
- Followed the [edition upgrade
guide](https://doc.rust-lang.org/edition-guide/editions/transitioning-an-existing-project-to-a-new-edition.html)
## Testing
- CI
---
## Summary of Changes
### Documentation Indentation
When using lists in documentation, proper indentation is now linted for.
This means subsequent lines within the same list item must start at the
same indentation level as the item.
```rust
/* Valid */
/// - Item 1
/// Run-on sentence.
/// - Item 2
struct Foo;
/* Invalid */
/// - Item 1
/// Run-on sentence.
/// - Item 2
struct Foo;
```
### Implicit `!` to `()` Conversion
`!` (the never return type, returned by `panic!`, etc.) no longer
implicitly converts to `()`. This is particularly painful for systems
with `todo!` or `panic!` statements, as they will no longer be functions
returning `()` (or `Result<()>`), making them invalid systems for
functions like `add_systems`. The ideal fix would be to accept functions
returning `!` (or rather, _not_ returning), but this is blocked on the
[stabilisation of the `!` type
itself](https://doc.rust-lang.org/std/primitive.never.html), which is
not done.
The "simple" fix would be to add an explicit `-> ()` to system
signatures (e.g., `|| { todo!() }` becomes `|| -> () { todo!() }`).
However, this is _also_ banned, as there is an existing lint which (IMO,
incorrectly) marks this as an unnecessary annotation.
So, the "fix" (read: workaround) is to put these kinds of `|| -> ! { ...
}` closuers into variables and give the variable an explicit type (e.g.,
`fn()`).
```rust
// Valid
let system: fn() = || todo!("Not implemented yet!");
app.add_systems(..., system);
// Invalid
app.add_systems(..., || todo!("Not implemented yet!"));
```
### Temporary Variable Lifetimes
The order in which temporary variables are dropped has changed. The
simple fix here is _usually_ to just assign temporaries to a named
variable before use.
### `gen` is a keyword
We can no longer use the name `gen` as it is reserved for a future
generator syntax. This involved replacing uses of the name `gen` with
`r#gen` (the raw-identifier syntax).
### Formatting has changed
Use statements have had the order of imports changed, causing a
substantial +/-3,000 diff when applied. For now, I have opted-out of
this change by amending `rustfmt.toml`
```toml
style_edition = "2021"
```
This preserves the original formatting for now, reducing the size of
this PR. It would be a simple followup to update this to 2024 and run
`cargo fmt`.
### New `use<>` Opt-Out Syntax
Lifetimes are now implicitly included in RPIT types. There was a handful
of instances where it needed to be added to satisfy the borrow checker,
but there may be more cases where it _should_ be added to avoid
breakages in user code.
### `MyUnitStruct { .. }` is an invalid pattern
Previously, you could match against unit structs (and unit enum
variants) with a `{ .. }` destructuring. This is no longer valid.
### Pretty much every use of `ref` and `mut` are gone
Pattern binding has changed to the point where these terms are largely
unused now. They still serve a purpose, but it is far more niche now.
### `iter::repeat(...).take(...)` is bad
New lint recommends using the more explicit `iter::repeat_n(..., ...)`
instead.
## Migration Guide
The lifetimes of functions using return-position impl-trait (RPIT) are
likely _more_ conservative than they had been previously. If you
encounter lifetime issues with such a function, please create an issue
to investigate the addition of `+ use<...>`.
## Notes
- Check the individual commits for a clearer breakdown for what
_actually_ changed.
---------
Co-authored-by: François Mockers <francois.mockers@vleue.com>
This adds an option to animate the materials in the `many_cubes` stress
test. Each material instance `base_color` is varied each frame.
This has been tested in conjunction with the
`--vary-material-data-per-instance` and `--material-texture-count`
options.
If `--vary-material-data-per-instance` is not used it will just update
the single material, otherwise it will update all of them. If
`--material-texture-count` is used the `base_color` is multiplied with
the texture so the effect is still visible.
Because this test is focused on the performance of updating material
data and not the performance of bevy's color system it uses its own
function (`fast_hue_to_rgb`) to quickly set the hue. This appeared to be
around 8x faster than using `base_color.set_hue(hue)` in the tight loop.
# Objective
I'm working on some PRs involving our font atlases and it would be nice
to be able to test these scenarios separately to better understand the
performance tradeoffs in different situations.
## Solution
Add a `many-font-sizes` option.
The old behavior is still available by running with `--many-glyphs
--many-font-sizes`.
## Testing
`cargo run --example many_text2d --release`
`cargo run --example many_text2d --release -- --many-glyphs`
`cargo run --example many_text2d --release -- --many-font-sizes`
`cargo run --example many_text2d --release -- --many-glyphs
--many-font-sizes`
# Objective
Add some multi-span text to the `many_buttons` benchmark by splitting up
each button label text into two different coloured text spans.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
- I was getting familiar with the many_components example to test some
recent pr's for executor changes and saw some things to improve.
## Solution
- Use `insert_by_ids` instead of `insert_by_id`. This reduces the number
of archetype moves and improves startup times substantially.
- Add a tracing span to `base_system`. I'm not sure why, but tracing
spans weren't showing for this system. I think it's something to do with
how pipe system works, but need to investigate more. The approach in
this pr is a little better than the default span too, since it allows
adding the number of entities queried to the span which is not possible
with the default system span.
- println the number of archetype component id's that are created. This
is useful since part of the purpose of this stress test is to test how
well the use of FixedBitSet scales in the executor.
## Testing
- Ran the example with `cargo run --example many_components -F
trace_tracy 1000000` and connected with tracy
- Timed the time it took to spawn 1 million entities on main (240 s) vs
this pr (15 s)
---
## Showcase

## Future Work
- Currently systems are created with a random set of components and
entities are created with a random set of components without any
correlation between the randomness. This means that some systems won't
match any entities and some entities could not match any systems. It
might be better to spawn the entities from the pool of components that
match the queries that the systems are using.
Fixes#17535
Bevy's approach to handling "entity mapping" during spawning and cloning
needs some work. The addition of
[Relations](https://github.com/bevyengine/bevy/pull/17398) both
[introduced a new "duplicate entities" bug when spawning scenes in the
scene system](#17535) and made the weaknesses of the current mapping
system exceedingly clear:
1. Entity mapping requires _a ton_ of boilerplate (implement or derive
VisitEntities and VisitEntitesMut, then register / reflect MapEntities).
Knowing the incantation is challenging and if you forget to do it in
part or in whole, spawning subtly breaks.
2. Entity mapping a spawned component in scenes incurs unnecessary
overhead: look up ReflectMapEntities, create a _brand new temporary
instance_ of the component using FromReflect, map the entities in that
instance, and then apply that on top of the actual component using
reflection. We can do much better.
Additionally, while our new [Entity cloning
system](https://github.com/bevyengine/bevy/pull/16132) is already pretty
great, it has some areas we can make better:
* It doesn't expose semantic info about the clone (ex: ignore or "clone
empty"), meaning we can't key off of that in places where it would be
useful, such as scene spawning. Rather than duplicating this info across
contexts, I think it makes more sense to add that info to the clone
system, especially given that we'd like to use cloning code in some of
our spawning scenarios.
* EntityCloner is currently built in a way that prioritizes a single
entity clone
* EntityCloner's recursive cloning is built to be done "inside out" in a
parallel context (queue commands that each have a clone of
EntityCloner). By making EntityCloner the orchestrator of the clone we
can remove internal arcs, improve the clarity of the code, make
EntityCloner mutable again, and simplify the builder code.
* EntityCloner does not currently take into account entity mapping. This
is necessary to do true "bullet proof" cloning, would allow us to unify
the per-component scene spawning and cloning UX, and ultimately would
allow us to use EntityCloner in place of raw reflection for scenes like
`Scene(World)` (which would give us a nice performance boost: fewer
archetype moves, less reflection overhead).
## Solution
### Improved Entity Mapping
First, components now have first-class "entity visiting and mapping"
behavior:
```rust
#[derive(Component, Reflect)]
#[reflect(Component)]
struct Inventory {
size: usize,
#[entities]
items: Vec<Entity>,
}
```
Any field with the `#[entities]` annotation will be viewable and
mappable when cloning and spawning scenes.
Compare that to what was required before!
```rust
#[derive(Component, Reflect, VisitEntities, VisitEntitiesMut)]
#[reflect(Component, MapEntities)]
struct Inventory {
#[visit_entities(ignore)]
size: usize,
items: Vec<Entity>,
}
```
Additionally, for relationships `#[entities]` is implied, meaning this
"just works" in scenes and cloning:
```rust
#[derive(Component, Reflect)]
#[relationship(relationship_target = Children)]
#[reflect(Component)]
struct ChildOf(pub Entity);
```
Note that Component _does not_ implement `VisitEntities` directly.
Instead, it has `Component::visit_entities` and
`Component::visit_entities_mut` methods. This is for a few reasons:
1. We cannot implement `VisitEntities for C: Component` because that
would conflict with our impl of VisitEntities for anything that
implements `IntoIterator<Item=Entity>`. Preserving that impl is more
important from a UX perspective.
2. We should not implement `Component: VisitEntities` VisitEntities in
the Component derive, as that would increase the burden of manual
Component trait implementors.
3. Making VisitEntitiesMut directly callable for components would make
it easy to invalidate invariants defined by a component author. By
putting it in the `Component` impl, we can make it harder to call
naturally / unavailable to autocomplete using `fn
visit_entities_mut(this: &mut Self, ...)`.
`ReflectComponent::apply_or_insert` is now
`ReflectComponent::apply_or_insert_mapped`. By moving mapping inside
this impl, we remove the need to go through the reflection system to do
entity mapping, meaning we no longer need to create a clone of the
target component, map the entities in that component, and patch those
values on top. This will make spawning mapped entities _much_ faster
(The default `Component::visit_entities_mut` impl is an inlined empty
function, so it will incur no overhead for unmapped entities).
### The Bug Fix
To solve #17535, spawning code now skips entities with the new
`ComponentCloneBehavior::Ignore` and
`ComponentCloneBehavior::RelationshipTarget` variants (note
RelationshipTarget is a temporary "workaround" variant that allows
scenes to skip these components. This is a temporary workaround that can
be removed as these cases should _really_ be using EntityCloner logic,
which should be done in a followup PR. When that is done,
`ComponentCloneBehavior::RelationshipTarget` can be merged into the
normal `ComponentCloneBehavior::Custom`).
### Improved Cloning
* `Option<ComponentCloneHandler>` has been replaced by
`ComponentCloneBehavior`, which encodes additional intent and context
(ex: `Default`, `Ignore`, `Custom`, `RelationshipTarget` (this last one
is temporary)).
* Global per-world entity cloning configuration has been removed. This
felt overly complicated, increased our API surface, and felt too
generic. Each clone context can have different requirements (ex: what a
user wants in a specific system, what a scene spawner wants, etc). I'd
prefer to see how far context-specific EntityCloners get us first.
* EntityCloner's internals have been reworked to remove Arcs and make it
mutable.
* EntityCloner is now directly stored on EntityClonerBuilder,
simplifying the code somewhat
* EntityCloner's "bundle scratch" pattern has been moved into the new
BundleScratch type, improving its usability and making it usable in
other contexts (such as future cross-world cloning code). Currently this
is still private, but with some higher level safe APIs it could be used
externally for making dynamic bundles
* EntityCloner's recursive cloning behavior has been "externalized". It
is now responsible for orchestrating recursive clones, meaning it no
longer needs to be sharable/clone-able across threads / read-only.
* EntityCloner now does entity mapping during clones, like scenes do.
This gives behavior parity and also makes it more generically useful.
* `RelatonshipTarget::RECURSIVE_SPAWN` is now
`RelationshipTarget::LINKED_SPAWN`, and this field is used when cloning
relationship targets to determine if cloning should happen recursively.
The new `LINKED_SPAWN` term was picked to make it more generically
applicable across spawning and cloning scenarios.
## Next Steps
* I think we should adapt EntityCloner to support cross world cloning. I
think this PR helps set the stage for that by making the internals
slightly more generalized. We could have a CrossWorldEntityCloner that
reuses a lot of this infrastructure.
* Once we support cross world cloning, we should use EntityCloner to
spawn `Scene(World)` scenes. This would yield significant performance
benefits (no archetype moves, less reflection overhead).
---------
Co-authored-by: eugineerd <70062110+eugineerd@users.noreply.github.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
- This PR adds a new stress test called `many_materials` to benchmark
the rendering performance of many animated materials.
- Fixes#11588
- This PR continues the work started in the previous PR #11592, which
was closed due to inactivity.
## Solution
- Created a new example (`examples/stress_tests/many_materials.rs`) that
renders a grid of cubes with animated materials.
- The size of the grid can be configured using the `-n` command-line
argument (or `--grid-size`). The default grid size is 10x10.
- The materials animate by cycling through colors in the HSL color
space.
## Testing
- I have tested these changes locally on my Linux machine.
- Reviewers can test the changes by running the example with different
grid sizes and observing the performance (FPS, frame time).
- I have not tested on other platforms (macOS, Windows, wasm), but I
expect it to work as the code uses standard Bevy features.
---
## Showcase
<details>
<summary>Click to view showcase</summary>

</details>
Fixes#17412
## Objective
`Parent` uses the "has a X" naming convention. There is increasing
sentiment that we should use the "is a X" naming convention for
relationships (following #17398). This leaves `Children` as-is because
there is prevailing sentiment that `Children` is clearer than `ParentOf`
in many cases (especially when treating it like a collection).
This renames `Parent` to `ChildOf`.
This is just the implementation PR. To discuss the path forward, do so
in #17412.
## Migration Guide
- The `Parent` component has been renamed to `ChildOf`.
This adds support for one-to-many non-fragmenting relationships (with
planned paths for fragmenting and non-fragmenting many-to-many
relationships). "Non-fragmenting" means that entities with the same
relationship type, but different relationship targets, are not forced
into separate tables (which would cause "table fragmentation").
Functionally, this fills a similar niche as the current Parent/Children
system. The biggest differences are:
1. Relationships have simpler internals and significantly improved
performance and UX. Commands and specialized APIs are no longer
necessary to keep everything in sync. Just spawn entities with the
relationship components you want and everything "just works".
2. Relationships are generalized. Bevy can provide additional built in
relationships, and users can define their own.
**REQUEST TO REVIEWERS**: _please don't leave top level comments and
instead comment on specific lines of code. That way we can take
advantage of threaded discussions. Also dont leave comments simply
pointing out CI failures as I can read those just fine._
## Built on top of what we have
Relationships are implemented on top of the Bevy ECS features we already
have: components, immutability, and hooks. This makes them immediately
compatible with all of our existing (and future) APIs for querying,
spawning, removing, scenes, reflection, etc. The fewer specialized APIs
we need to build, maintain, and teach, the better.
## Why focus on one-to-many non-fragmenting first?
1. This allows us to improve Parent/Children relationships immediately,
in a way that is reasonably uncontroversial. Switching our hierarchy to
fragmenting relationships would have significant performance
implications. ~~Flecs is heavily considering a switch to non-fragmenting
relations after careful considerations of the performance tradeoffs.~~
_(Correction from @SanderMertens: Flecs is implementing non-fragmenting
storage specialized for asset hierarchies, where asset hierarchies are
many instances of small trees that have a well defined structure)_
2. Adding generalized one-to-many relationships is currently a priority
for the [Next Generation Scene / UI
effort](https://github.com/bevyengine/bevy/discussions/14437).
Specifically, we're interested in building reactions and observers on
top.
## The changes
This PR does the following:
1. Adds a generic one-to-many Relationship system
3. Ports the existing Parent/Children system to Relationships, which now
lives in `bevy_ecs::hierarchy`. The old `bevy_hierarchy` crate has been
removed.
4. Adds on_despawn component hooks
5. Relationships can opt-in to "despawn descendants" behavior, meaning
that the entire relationship hierarchy is despawned when
`entity.despawn()` is called. The built in Parent/Children hierarchies
enable this behavior, and `entity.despawn_recursive()` has been removed.
6. `world.spawn` now applies commands after spawning. This ensures that
relationship bookkeeping happens immediately and removes the need to
manually flush. This is in line with the equivalent behaviors recently
added to the other APIs (ex: insert).
7. Removes the ValidParentCheckPlugin (system-driven / poll based) in
favor of a `validate_parent_has_component` hook.
## Using Relationships
The `Relationship` trait looks like this:
```rust
pub trait Relationship: Component + Sized {
type RelationshipSources: RelationshipSources<Relationship = Self>;
fn get(&self) -> Entity;
fn from(entity: Entity) -> Self;
}
```
A relationship is a component that:
1. Is a simple wrapper over a "target" Entity.
2. Has a corresponding `RelationshipSources` component, which is a
simple wrapper over a collection of entities. Every "target entity"
targeted by a "source entity" with a `Relationship` has a
`RelationshipSources` component, which contains every "source entity"
that targets it.
For example, the `Parent` component (as it currently exists in Bevy) is
the `Relationship` component and the entity containing the Parent is the
"source entity". The entity _inside_ the `Parent(Entity)` component is
the "target entity". And that target entity has a `Children` component
(which implements `RelationshipSources`).
In practice, the Parent/Children relationship looks like this:
```rust
#[derive(Relationship)]
#[relationship(relationship_sources = Children)]
pub struct Parent(pub Entity);
#[derive(RelationshipSources)]
#[relationship_sources(relationship = Parent)]
pub struct Children(Vec<Entity>);
```
The Relationship and RelationshipSources derives automatically implement
Component with the relevant configuration (namely, the hooks necessary
to keep everything in sync).
The most direct way to add relationships is to spawn entities with
relationship components:
```rust
let a = world.spawn_empty().id();
let b = world.spawn(Parent(a)).id();
assert_eq!(world.entity(a).get::<Children>().unwrap(), &[b]);
```
There are also convenience APIs for spawning more than one entity with
the same relationship:
```rust
world.spawn_empty().with_related::<Children>(|s| {
s.spawn_empty();
s.spawn_empty();
})
```
The existing `with_children` API is now a simpler wrapper over
`with_related`. This makes this change largely non-breaking for existing
spawn patterns.
```rust
world.spawn_empty().with_children(|s| {
s.spawn_empty();
s.spawn_empty();
})
```
There are also other relationship APIs, such as `add_related` and
`despawn_related`.
## Automatic recursive despawn via the new on_despawn hook
`RelationshipSources` can opt-in to "despawn descendants" behavior,
which will despawn all related entities in the relationship hierarchy:
```rust
#[derive(RelationshipSources)]
#[relationship_sources(relationship = Parent, despawn_descendants)]
pub struct Children(Vec<Entity>);
```
This means that `entity.despawn_recursive()` is no longer required.
Instead, just use `entity.despawn()` and the relevant related entities
will also be despawned.
To despawn an entity _without_ despawning its parent/child descendants,
you should remove the `Children` component first, which will also remove
the related `Parent` components:
```rust
entity
.remove::<Children>()
.despawn()
```
This builds on the on_despawn hook introduced in this PR, which is fired
when an entity is despawned (before other hooks).
## Relationships are the source of truth
`Relationship` is the _single_ source of truth component.
`RelationshipSources` is merely a reflection of what all the
`Relationship` components say. By embracing this, we are able to
significantly improve the performance of the system as a whole. We can
rely on component lifecycles to protect us against duplicates, rather
than needing to scan at runtime to ensure entities don't already exist
(which results in quadratic runtime). A single source of truth gives us
constant-time inserts. This does mean that we cannot directly spawn
populated `Children` components (or directly add or remove entities from
those components). I personally think this is a worthwhile tradeoff,
both because it makes the performance much better _and_ because it means
theres exactly one way to do things (which is a philosophy we try to
employ for Bevy APIs).
As an aside: treating both sides of the relationship as "equivalent
source of truth relations" does enable building simple and flexible
many-to-many relationships. But this introduces an _inherent_ need to
scan (or hash) to protect against duplicates.
[`evergreen_relations`](https://github.com/EvergreenNest/evergreen_relations)
has a very nice implementation of the "symmetrical many-to-many"
approach. Unfortunately I think the performance issues inherent to that
approach make it a poor choice for Bevy's default relationship system.
## Followup Work
* Discuss renaming `Parent` to `ChildOf`. I refrained from doing that in
this PR to keep the diff reasonable, but I'm personally biased toward
this change (and using that naming pattern generally for relationships).
* [Improved spawning
ergonomics](https://github.com/bevyengine/bevy/discussions/16920)
* Consider adding relationship observers/triggers for "relationship
targets" whenever a source is added or removed. This would replace the
current "hierarchy events" system, which is unused upstream but may have
existing users downstream. I think triggers are the better fit for this
than a buffered event queue, and would prefer not to add that back.
* Fragmenting relations: My current idea hinges on the introduction of
"value components" (aka: components whose type _and_ value determines
their ComponentId, via something like Hashing / PartialEq). By labeling
a Relationship component such as `ChildOf(Entity)` as a "value
component", `ChildOf(e1)` and `ChildOf(e2)` would be considered
"different components". This makes the transition between fragmenting
and non-fragmenting a single flag, and everything else continues to work
as expected.
* Many-to-many support
* Non-fragmenting: We can expand Relationship to be a list of entities
instead of a single entity. I have largely already written the code for
this.
* Fragmenting: With the "value component" impl mentioned above, we get
many-to-many support "for free", as it would allow inserting multiple
copies of a Relationship component with different target entities.
Fixes#3742 (If this PR is merged, I think we should open more targeted
followup issues for the work above, with a fresh tracking issue free of
the large amount of less-directed historical context)
Fixes#17301Fixes#12235Fixes#15299Fixes#15308
## Migration Guide
* Replace `ChildBuilder` with `ChildSpawnerCommands`.
* Replace calls to `.set_parent(parent_id)` with
`.insert(Parent(parent_id))`.
* Replace calls to `.replace_children()` with `.remove::<Children>()`
followed by `.add_children()`. Note that you'll need to manually despawn
any children that are not carried over.
* Replace calls to `.despawn_recursive()` with `.despawn()`.
* Replace calls to `.despawn_descendants()` with
`.despawn_related::<Children>()`.
* If you have any calls to `.despawn()` which depend on the children
being preserved, you'll need to remove the `Children` component first.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Fixes https://github.com/bevyengine/bevy/issues/17111
## Solution
Move `#![warn(clippy::allow_attributes,
clippy::allow_attributes_without_reason)]` to the workspace `Cargo.toml`
## Testing
Lots of CI testing, and local testing too.
---------
Co-authored-by: Benjamin Brienen <benjamin.brienen@outlook.com>
# Objective
I have an application where I'd like to measure average frame rate over
the entire life of the application, and it would be handy if I could
just configure this on the existing `FrameTimeDiagnosticsPlugin`.
Probably fixes#10948?
## Solution
Add `max_history_length` to `FrameTimeDiagnosticsPlugin`, and because
`smoothing_factor` seems to be based on history length, add that too.
## Discussion
I'm not totally sure that `DEFAULT_MAX_HISTORY_LENGTH` is a great
default for `FrameTimeDiagnosticsPlugin` (or any diagnostic?). That's
1/3 of a second at typical game frame rates. Moreover, the default print
interval for `LogDiagnosticsPlugin` is 1 second. So when the two are
combined, you are printing the average over the last third of the
duration between now and the previous print, which seems a bit wonky.
(related: #11429)
I'm pretty sure this default value discussed and the current value
wasn't totally arbitrary though.
Maybe it would be nice for `Diagnostic` to have a
`with_max_history_length_and_also_calculate_a_good_default_smoothing_factor`
method? And then make an explicit smoothing factor in
`FrameTimeDiagnosticsPlugin` optional?
Or add a `new(max_history_length: usize)` method to
`FrameTimeDiagnosticsPlugin` that sets a reasonable default
`smoothing_factor`? edit: This one seems like a no-brainer, doing it.
## Alternatives
It's really easy to roll your own `FrameTimeDiagnosticsPlugin`, but that
might not be super interoperable with, for example, third party FPS
overlays. Still, might be the right call.
## Testing
`cargo run --example many_sprites` (modified to use a custom
`max_history_length`)
## Migration Guide
`FrameTimeDiagnosticsPlugin` now contains two fields. Use
`FrameTimeDiagnosticsPlugin::default()` to match Bevy's previous
behavior or, for example, `FrameTimeDiagnosticsPlugin::new(60)` to
configure it.
# Objective
Fixes#16783
## Solution
Works around a `cosmic-text` bug or limitation by triggering a re-layout
with the calculated width from the first layout run. See linked issue.
Credit to @ickshonpe for the clever solution.
## Performance
This has a significant performance impact only on unbounded text that
are not `JustifyText::Left`, which is still a bit of a bummer because
text2d performance in 0.15.1 is already not great. But this seems better
than alignment not working.
||many_text2d nfc re|many_text2d nfc re center|
|-|-|-|
|unbounded-layout-no-fix|3.06|3.10|
|unbounded-layout-fix|3.05 ⬜ -0.2%|2.71 🟥 -12.5%|
## Testing
I added a centered text to the `text2d` example.
`cargo run --example text2d`
We should look at other text examples and stress tests. I haven't tested
as thoroughly as I would like, so help testing that this doesn't break
something in UI would be appreciated.
# Objective
Many instances of `clippy::too_many_arguments` linting happen to be on
systems - functions which we don't call manually, and thus there's not
much reason to worry about the argument count.
## Solution
Allow `clippy::too_many_arguments` globally, and remove all lint
attributes related to it.
# Objective
Make this `stress_test` more consistent with others.
## Solution
Add `LogDiagnosticsPlugin`
## Testing
`cargo run --example many_gizmos`, observe frame rate now being logged.
# Objective
- Contributes to #11478
- Contributes to #16877
## Solution
- Removed everything except `Instant` from `bevy_utils::time`
## Testing
- CI
---
## Migration Guide
If you relied on any of the following from `bevy_utils::time`:
- `Duration`
- `TryFromFloatSecsError`
Import these directly from `core::time` regardless of platform target
(WASM, mobile, etc.)
If you relied on any of the following from `bevy_utils::time`:
- `SystemTime`
- `SystemTimeError`
Instead import these directly from either `std::time` or `web_time` as
appropriate for your target platform.
## Notes
`Duration` and `TryFromFloatSecsError` are both re-exports from
`core::time` regardless of whether they are used from `web_time` or
`std::time`, so there is no value gained from re-exporting them from
`bevy_utils::time` as well. As for `SystemTime` and `SystemTimeError`,
no Bevy internal crates or examples rely on these types. Since Bevy
doesn't have a `Time<Wall>` resource for interacting with wall-time (and
likely shouldn't need one), I think removing these from `bevy_utils`
entirely and waiting for a use-case to justify inclusion is a reasonable
path forward.
# Objective
Fixes#17098
It seems that it's not totally obvious how to fix this, but that
reverting might be part of the solution anyway.
Let's get the repo back into a working state.
## Solution
Revert the [recent
optimization](https://github.com/bevyengine/bevy/pull/17078) that broke
"many-to-one main->render world entities" for 2d.
## Testing
`cargo run --example text2d`
`cargo run --example sprite_slice`
# Objective
- Fix sprite rendering performance regression since retained render
world changes
- The retained render world changes moved `ExtractedSprites` from using
the highly-optimised `EntityHasher` with an `Entity` to using
`FixedHasher` with `(Entity, MainEntity)`. This was enough to regress
framerate in bevymark by 25%.
## Solution
- Move the render world entity into a member of `ExtractedSprite` and
change `ExtractedSprites` to use `MainEntityHashMap` for its storage
- Disable sprite picking in bevymark
## Testing
M4 Max. `bevymark --waves 100 --per-wave 1000 --benchmark`. main in
yellow vs PR in red:
<img width="590" alt="Screenshot 2025-01-01 at 16 36 22"
src="https://github.com/user-attachments/assets/1e4ed6ec-3811-4abf-8b30-336153737f89"
/>
20.2% median frame time reduction.
<img width="594" alt="Screenshot 2025-01-01 at 16 38 37"
src="https://github.com/user-attachments/assets/157c2022-cda6-4cf2-bc63-d0bc40528cf0"
/>
49.7% median extract_sprites execution time reduction.
Comparing 0.14.2 yellow vs PR red:
<img width="593" alt="Screenshot 2025-01-01 at 16 40 06"
src="https://github.com/user-attachments/assets/abd59b6f-290a-4eb6-8835-ed110af995f3"
/>
~6.1% median frame time reduction.
---
## Migration Guide
- `ExtractedSprites` is now using `MainEntityHashMap` for storage, which
is keyed on `MainEntity`.
- The render world entity corresponding to an `ExtractedSprite` is now
stored in the `render_entity` member of it.
# Objective
Add commandline options to `many_glyphs` to disable the `Text2d` or `UI`
text for more targeted benching.
## Solution
* Use `Argh` to manage the commandline options for `many_glyphs`.
* Added `no-ui` and `no-text2d` commandline options.
# Objective
Make it easier to test for `Text2d` performance regressions.
Related to #16972
## Solution
Add a new `stress_test`, based on `many_sprites` and other existing
stress tests.
The `many-glyphs` option is inspired by
https://github.com/bevyengine/bevy/issues/16901#issuecomment-2558572382.
## Testing
```bash
cargo run --release --example many_text2d -- --help
cargo run --release --example many_text2d
cargo run --release --example many_text2d -- --many_glyphs
```
etc
# Objective
Add a benchmark that captures performance with a removed UI layout where
the root node is set to `Display::None`.
# Solution
Added a `display-none` commandline argument to the `many_buttons`
example. When used `display-none` sets the `display` field of the root
node to `Display::None`.
# Testing
```
cargo run --example many_buttons -- --display-none
```
Which displays nothing, as desired.
This patch replaces the undocumented `NoGpuCulling` component with a new
component, `NoIndirectDrawing`, effectively turning indirect drawing on
by default. Indirect mode is needed for the recently-landed multidraw
feature (#16427). Since multidraw is such a win for performance, when
that feature is supported the small performance tax that indirect mode
incurs is virtually always worth paying.
To ensure that custom drawing code such as that in the
`custom_shader_instancing` example continues to function, this commit
additionally makes GPU culling take the `NoFrustumCulling` component
into account.
This PR is an alternative to #16670 that doesn't break the
`custom_shader_instancing` example. **PR #16755 should land first in
order to avoid breaking deferred rendering, as multidraw currently
breaks it**.
## Migration Guide
* Indirect drawing (GPU culling) is now enabled by default, so the
`GpuCulling` component is no longer available. To disable indirect mode,
which may be useful with custom render nodes, add the new
`NoIndirectDrawing` component to your camera.
# Objective
We currently have no benchmarks for large worlds with many entities,
components and systems.
Having a benchmark for a world with many components is especially useful
for the performance improvements needed for relations. This is also a
response to this [comment from
cart](https://github.com/bevyengine/bevy/pull/14385#issuecomment-2311292546).
> I'd like both a small bevy_ecs-scoped executor benchmark that
generates thousands of components used by hundreds of systems.
## Solution
I use dynamic components and components to construct a benchmark with
2000 components, 4000 systems, and 10000 entities.
## Some notes
- ~I use a lot of random entities, which creates unpredictable
performance, I should use a seeded PRNG.~
- Not entirely sure if everything is ran concurrently currently. And
there are many conflicts, meaning there's probably a lot of
first-come-first-serve going on. Not entirely sure if these benchmarks
are very reproducible.
- Maybe add some more safety comments
- Also component_reads_and_writes() is about to be deprecated #16339,
but there's no other way to currently do what I'm trying to do.
---------
Co-authored-by: Chris Russell <8494645+chescock@users.noreply.github.com>
Co-authored-by: BD103 <59022059+BD103@users.noreply.github.com>
# Objective
To capture the performance impact of removing and adding UI nodes add a
`respawn` commandline argument to the `many_buttons` stress test example
that despawns the existing UI layout and then spawns a new layout to
replace it every frame.
## Testing
To run the example with the new changes use:
```cargo run --example many_buttons --release -- --respawn```
# Objective
_If I understand it correctly_, we were checking mesh visibility, as
well as re-rendering point and spot light shadow maps for each view.
This makes it so that M views and N lights produce M x N complexity.
This PR aims to fix that, as well as introduce a stress test for this
specific scenario.
## Solution
- Keep track of what lights have already had mesh visibility calculated
and do not calculate it again;
- Reuse shadow depth textures and attachments across all views, and only
render shadow maps for the _first_ time a light is encountered on a
view;
- Directional lights remain unaltered, since their shadow map cascades
are view-dependent;
- Add a new `many_cameras_lights` stress test example to verify the
solution
## Showcase
110% speed up on the stress test
83% reduction of memory usage in stress test
### Before (5.35 FPS on stress test)
<img width="1392" alt="Screenshot 2024-09-11 at 12 25 57"
src="https://github.com/user-attachments/assets/136b0785-e9a4-44df-9a22-f99cc465e126">
### After (11.34 FPS on stress test)
<img width="1392" alt="Screenshot 2024-09-11 at 12 24 35"
src="https://github.com/user-attachments/assets/b8dd858f-5e19-467f-8344-2b46ca039630">
## Testing
- Did you test these changes? If so, how?
- On my game project where I have two cameras, and many shadow casting
lights I managed to get pretty much double the FPS.
- Also included a stress test, see the comparison above
- Are there any parts that need more testing?
- Yes, I would like help verifying that this fix is indeed correct, and
that we were really re-rendering the shadow maps by mistake and it's
indeed okay to not do that
- How can other people (reviewers) test your changes? Is there anything
specific they need to know?
- Run the `many_cameras_lights` example
- On the `main` branch, cherry pick the commit with the example (`git
cherry-pick --no-commit 1ed4ace01`) and run it
- If relevant, what platforms did you test these changes on, and are
there any important ones you can't test?
- macOS
---------
Co-authored-by: François Mockers <francois.mockers@vleue.com>
# Objective
Continue improving the user experience of our UI Node API in the
direction specified by [Bevy's Next Generation Scene / UI
System](https://github.com/bevyengine/bevy/discussions/14437)
## Solution
As specified in the document above, merge `Style` fields into `Node`,
and move "computed Node fields" into `ComputedNode` (I chose this name
over something like `ComputedNodeLayout` because it currently contains
more than just layout info. If we want to break this up / rename these
concepts, lets do that in a separate PR). `Style` has been removed.
This accomplishes a number of goals:
## Ergonomics wins
Specifying both `Node` and `Style` is now no longer required for
non-default styles
Before:
```rust
commands.spawn((
Node::default(),
Style {
width: Val::Px(100.),
..default()
},
));
```
After:
```rust
commands.spawn(Node {
width: Val::Px(100.),
..default()
});
```
## Conceptual clarity
`Style` was never a comprehensive "style sheet". It only defined "core"
style properties that all `Nodes` shared. Any "styled property" that
couldn't fit that mold had to be in a separate component. A "real" style
system would style properties _across_ components (`Node`, `Button`,
etc). We have plans to build a true style system (see the doc linked
above).
By moving the `Style` fields to `Node`, we fully embrace `Node` as the
driving concept and remove the "style system" confusion.
## Next Steps
* Consider identifying and splitting out "style properties that aren't
core to Node". This should not happen for Bevy 0.15.
---
## Migration Guide
Move any fields set on `Style` into `Node` and replace all `Style`
component usage with `Node`.
Before:
```rust
commands.spawn((
Node::default(),
Style {
width: Val::Px(100.),
..default()
},
));
```
After:
```rust
commands.spawn(Node {
width: Val::Px(100.),
..default()
});
```
For any usage of the "computed node properties" that used to live on
`Node`, use `ComputedNode` instead:
Before:
```rust
fn system(nodes: Query<&Node>) {
for node in &nodes {
let computed_size = node.size();
}
}
```
After:
```rust
fn system(computed_nodes: Query<&ComputedNode>) {
for computed_node in &computed_nodes {
let computed_size = computed_node.size();
}
}
```
# Objective
Fixes#15791.
As raised in #11022, scaling orthographic cameras is confusing! In Bevy
0.14, there were multiple completely redundant ways to do this, and no
clear guidance on which to use.
As a result, #15075 removed the `scale` field from
`OrthographicProjection` completely, solving the redundancy issue.
However, this resulted in an unintuitive API and a painful migration, as
discussed in #15791. Users simply want to change a single parameter to
zoom, rather than deal with the irrelevant details of how the camera is
being scaled.
## Solution
This PR reverts #15075, and takes an alternate, more nuanced approach to
the redundancy problem. `ScalingMode::WindowSize` was by far the biggest
offender. This was the default variant, and stored a float that was
*fully* redundant to setting `scale`.
All of the other variants contained meaningful semantic information and
had an intuitive scale. I could have made these unitless, storing an
aspect ratio, but this would have been a worse API and resulted in a
pointlessly painful migration.
In the course of this work I've also:
- improved the documentation to explain that you should just set `scale`
to zoom cameras
- swapped to named fields for all of the variants in `ScalingMode` for
more clarity about the parameter meanings
- substantially improved the `projection_zoom` example
- removed the footgunny `Mul` and `Div` impls for `ScalingMode`,
especially since these no longer have the intended effect on
`ScalingMode::WindowSize`.
- removed a rounding step because this is now redundant 🎉
## Testing
I've tested these changes as part of my work in the `projection_zoom`
example, and things seem to work fine.
## Migration Guide
`ScalingMode` has been refactored for clarity, especially on how to zoom
orthographic cameras and their projections:
- `ScalingMode::WindowSize` no longer stores a float, and acts as if its
value was 1. Divide your camera's scale by any previous value to achieve
identical results.
- `ScalingMode::FixedVertical` and `FixedHorizontal` now use named
fields.
---------
Co-authored-by: MiniaczQ <xnetroidpl@gmail.com>
Fixes#15834
## Migration Guide
The APIs of `Time`, `Timer` and `Stopwatch` have been cleaned up for
consistency with each other and the standard library's `Duration` type.
The following methods have been renamed:
- `Stowatch::paused` -> `Stopwatch::is_paused`
- `Time::elapsed_seconds` -> `Time::elasped_secs` (including `_f64` and
`_wrapped` variants)
# Objective
Cleanup naming and docs, add missing migration guide after #15591
All text root nodes now use `Text` (UI) / `Text2d`.
All text readers/writers use `Text<Type>Reader`/`Text<Type>Writer`
convention.
---
## Migration Guide
Doubles as #15591 migration guide.
Text bundles (`TextBundle` and `Text2dBundle`) were removed in favor of
`Text` and `Text2d`.
Shared configuration fields were replaced with `TextLayout`, `TextFont`
and `TextColor` components.
Just `TextBundle`'s additional field turned into `TextNodeFlags`
component,
while `Text2dBundle`'s additional fields turned into `TextBounds` and
`Anchor` components.
Text sections were removed in favor of hierarchy-based approach.
For root text entities with `Text` or `Text2d` components, child
entities with `TextSpan` will act as additional text sections.
To still access text spans by index, use the new `TextUiReader`,
`Text2dReader` and `TextUiWriter`, `Text2dWriter` system parameters.
# Objective
- closes#15866
## Solution
- Simply migrate where possible.
## Testing
- Expect that CI will do most of the work. Examples is another way of
testing this, as most of the work is in that area.
---
## Notes
For now, this PR doesn't migrate `QueryState::single` and friends as for
now, this look like another issue. So for example, QueryBuilders that
used single or `World::query` that used single wasn't migrated. If there
is a easy way to migrate those, please let me know.
Most of the uses of `Query::single` were removed, the only other uses
that I found was related to tests of said methods, so will probably be
removed when we remove `Query::single`.
# Objective
- Required components replace bundles, but `SpatialBundle` is yet to be
deprecated
## Solution
- Deprecate `SpatialBundle`
- Insert `Transform` and `Visibility` instead in examples using it
- In `spawn` or `insert` inserting a default `Transform` or `Visibility`
with component already requiring either, remove those components from
the tuple
## Testing
- Did you test these changes? If so, how?
Yes, I ran the examples I changed and tests
- Are there any parts that need more testing?
The `gamepad_viewer` and and `custom_shader_instancing` examples don't
work as intended due to entirely unrelated code, didn't check main.
- How can other people (reviewers) test your changes? Is there anything
specific they need to know?
Run examples, or just check that all spawned values are identical
- If relevant, what platforms did you test these changes on, and are
there any important ones you can't test?
Linux, wayland trough x11 (cause that's the default feature)
---
## Migration Guide
`SpatialBundle` is now deprecated, insert `Transform` and `Visibility`
instead which will automatically insert all other components that were
in the bundle. If you do not specify these values and any other
components in your `spawn`/`insert` call already requires either of
these components you can leave that one out.
before:
```rust
commands.spawn(SpatialBundle::default());
```
after:
```rust
commands.spawn((Transform::default(), Visibility::default());
```
# Objective
Currently text is recomputed unnecessarily on any changes to its color,
which is extremely expensive.
## Solution
Split up `TextStyle` into two separate components `TextFont` and
`TextColor`.
## Testing
I added this system to `many_buttons`:
```rust
fn set_text_colors_changed(mut colors: Query<&mut TextColor>) {
for mut text_color in colors.iter_mut() {
text_color.set_changed();
}
}
```
reports ~4fps on main, ~50fps with this PR.
## Migration Guide
`TextStyle` has been renamed to `TextFont` and its `color` field has
been moved to a separate component named `TextColor` which newtypes
`Color`.
**Ready for review. Examples migration progress: 100%.**
# Objective
- Implement https://github.com/bevyengine/bevy/discussions/15014
## Solution
This implements [cart's
proposal](https://github.com/bevyengine/bevy/discussions/15014#discussioncomment-10574459)
faithfully except for one change. I separated `TextSpan` from
`TextSpan2d` because `TextSpan` needs to require the `GhostNode`
component, which is a `bevy_ui` component only usable by UI.
Extra changes:
- Added `EntityCommands::commands_mut` that returns a mutable reference.
This is a blocker for extension methods that return something other than
`self`. Note that `sickle_ui`'s `UiBuilder::commands` returns a mutable
reference for this reason.
## Testing
- [x] Text examples all work.
---
## Showcase
TODO: showcase-worthy
## Migration Guide
TODO: very breaking
### Accessing text spans by index
Text sections are now text sections on different entities in a
hierarchy, Use the new `TextReader` and `TextWriter` system parameters
to access spans by index.
Before:
```rust
fn refresh_text(mut query: Query<&mut Text, With<TimeText>>, time: Res<Time>) {
let text = query.single_mut();
text.sections[1].value = format_time(time.elapsed());
}
```
After:
```rust
fn refresh_text(
query: Query<Entity, With<TimeText>>,
mut writer: UiTextWriter,
time: Res<Time>
) {
let entity = query.single();
*writer.text(entity, 1) = format_time(time.elapsed());
}
```
### Iterating text spans
Text spans are now entities in a hierarchy, so the new `UiTextReader`
and `UiTextWriter` system parameters provide ways to iterate that
hierarchy. The `UiTextReader::iter` method will give you a normal
iterator over spans, and `UiTextWriter::for_each` lets you visit each of
the spans.
---------
Co-authored-by: ickshonpe <david.curthoys@googlemail.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
Continue migration of bevy APIs to required components, following
guidance of https://hackmd.io/@bevy/required_components/
## Solution
- Make `Sprite` require `Transform` and `Visibility` and
`SyncToRenderWorld`
- move image and texture atlas handles into `Sprite`
- deprecate `SpriteBundle`
- remove engine uses of `SpriteBundle`
## Testing
ran cargo tests on bevy_sprite and tested several sprite examples.
---
## Migration Guide
Replace all uses of `SpriteBundle` with `Sprite`. There are several new
convenience constructors: `Sprite::from_image`,
`Sprite::from_atlas_image`, `Sprite::from_color`.
WARNING: use of `Handle<Image>` and `TextureAtlas` as components on
sprite entities will NO LONGER WORK. Use the fields on `Sprite` instead.
I would have removed the `Component` impls from `TextureAtlas` and
`Handle<Image>` except it is still used within ui. We should fix this
moving forward with the migration.
# Objective
- Closes#15717
## Solution
- Wrap the handle in a new wrapper component: `AnimationGraphHandle`.
## Testing
Searched for all instances of `AnimationGraph` in the examples and
updated and tested those
## Migration Guide
`Handle<AnimationGraph>` is no longer a component. Instead, use the
`AnimationGraphHandle` component which contains a
`Handle<AnimationGraph>`.
# Objective
After merging retained rendering world #15320, we now have a good way of
creating a link between worlds (*HIYAA intensifies*). This means that
`get_or_spawn` is no longer necessary for that function. Entity should
be opaque as the warning above `get_or_spawn` says. This is also part of
#15459.
I'm deprecating `get_or_spawn_batch` in a different PR in order to keep
the PR small in size.
## Solution
Deprecate `get_or_spawn` and replace it with `get_entity` in most
contexts. If it's possible to query `&RenderEntity`, then the entity is
synced and `render_entity.id()` is initialized in the render world.
## Migration Guide
If you are given an `Entity` and you want to do something with it, use
`Commands.entity(...)` or `World.entity(...)`. If instead you want to
spawn something use `Commands.spawn(...)` or `World.spawn(...)`. If you
are not sure if an entity exists, you can always use `get_entity` and
match on the `Option<...>` that is returned.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Yet another PR for migrating stuff to required components. This time,
cameras!
## Solution
As per the [selected
proposal](https://hackmd.io/tsYID4CGRiWxzsgawzxG_g#Combined-Proposal-1-Selected),
deprecate `Camera2dBundle` and `Camera3dBundle` in favor of `Camera2d`
and `Camera3d`.
Adding a `Camera` without `Camera2d` or `Camera3d` now logs a warning,
as suggested by Cart [on
Discord](https://discord.com/channels/691052431525675048/1264881140007702558/1291506402832945273).
I would personally like cameras to work a bit differently and be split
into a few more components, to avoid some footguns and confusing
semantics, but that is more controversial, and shouldn't block this core
migration.
## Testing
I ran a few 2D and 3D examples, and tried cameras with and without
render graphs.
---
## Migration Guide
`Camera2dBundle` and `Camera3dBundle` have been deprecated in favor of
`Camera2d` and `Camera3d`. Inserting them will now also insert the other
components required by them automatically.
As discussed in #15521
- Partial revert of #14897, reverting the change to the methods to
consume `self`
- The `insert_if` method is kept
The migration guide of #14897 should be removed
Closes#15521
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
A step in the migration to required components: scenes!
## Solution
As per the [selected
proposal](https://hackmd.io/@bevy/required_components/%2FPJtNGVMMQhyM0zIvCJSkbA):
- Deprecate `SceneBundle` and `DynamicSceneBundle`.
- Add `SceneRoot` and `DynamicSceneRoot` components, which wrap a
`Handle<Scene>` and `Handle<DynamicScene>` respectively.
## Migration Guide
Asset handles for scenes and dynamic scenes must now be wrapped in the
`SceneRoot` and `DynamicSceneRoot` components. Raw handles as components
no longer spawn scenes.
Additionally, `SceneBundle` and `DynamicSceneBundle` have been
deprecated. Instead, use the scene components directly.
Previously:
```rust
let model_scene = asset_server.load(GltfAssetLabel::Scene(0).from_asset("model.gltf"));
commands.spawn(SceneBundle {
scene: model_scene,
transform: Transform::from_xyz(-4.0, 0.0, -3.0),
..default()
});
```
Now:
```rust
let model_scene = asset_server.load(GltfAssetLabel::Scene(0).from_asset("model.gltf"));
commands.spawn((
SceneRoot(model_scene),
Transform::from_xyz(-4.0, 0.0, -3.0),
));
```
# Objective
- Improve code quality in preparation for
https://github.com/bevyengine/bevy/discussions/15014
## Solution
- Rename BreakLineOn to LineBreak.
## Migration Guide
`BreakLineOn` was renamed to `LineBreak`, and paramters named
`linebreak_behavior` were renamed to `linebreak`.
# 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:


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>
# Objective
Another step in the migration to required components: lights!
Note that this does not include `EnvironmentMapLight` or reflection
probes yet, because their API hasn't been fully chosen yet.
## Solution
As per the [selected
proposals](https://hackmd.io/@bevy/required_components/%2FLLnzwz9XTxiD7i2jiUXkJg):
- Deprecate `PointLightBundle` in favor of the `PointLight` component
- Deprecate `SpotLightBundle` in favor of the `PointLight` component
- Deprecate `DirectionalLightBundle` in favor of the `DirectionalLight`
component
## Testing
I ran some examples with lights.
---
## Migration Guide
`PointLightBundle`, `SpotLightBundle`, and `DirectionalLightBundle` have
been deprecated. Use the `PointLight`, `SpotLight`, and
`DirectionalLight` components instead. Adding them will now insert the
other components required by them automatically.