# Objective
- wgpu 0.20 made workgroup vars stop being zero-init by default. this
broke some applications (cough foresight cough) and now we workaround
it. wgpu exposes a compilation option that zero initializes workgroup
memory by default, but bevy does not expose it.
## Solution
- expose the compilation option wgpu gives us
## Testing
- ran examples: 3d_scene, compute_shader_game_of_life, gpu_readback,
lines, specialized_mesh_pipeline. they all work
- confirmed fix for our own problems
---
</details>
## Migration Guide
- add `zero_initialize_workgroup_memory: false,` to
`ComputePipelineDescriptor` or `RenderPipelineDescriptor` structs to
preserve 0.14 functionality, add `zero_initialize_workgroup_memory:
true,` to restore bevy 0.13 functionality.
# 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
In `queue_shadows`, the `UiBoxShadows` option is unwrapped incorrectly
which results in the number of shadow samples being set to
`u32::default()` instead of `UiBoxShadows::default()` if the camera
entity doesn't have the component.
## Solution
Just use `unwrap_or_default` directly without `map`.
# Objective
#15320 is a particularly painful breaking change, and the new
`RenderEntity` in particular is very noisy, with a lot of `let entity =
entity.id()` spam.
## Solution
Implement `WorldQuery`, `QueryData` and `ReadOnlyQueryData` for
`RenderEntity` and `WorldEntity`.
These work the same as the `Entity` impls from a user-facing
perspective: they simply return an owned (copied) `Entity` identifier.
This dramatically reduces noise and eases migration.
Under the hood, these impls defer to the implementations for `&T` for
everything other than the "call .id() for the user" bit, as they involve
read-only access to component data. Doing it this way (as opposed to
implementing a custom fetch, as tried in the first commit) dramatically
reduces the maintenance risk of complex unsafe code outside of
`bevy_ecs`.
To make this easier (and encourage users to do this themselves!), I've
made `ReadFetch` and `WriteFetch` slightly more public: they're no
longer `doc(hidden)`. This is a good change, since trying to vendor the
logic is much worse than just deferring to the existing tested impls.
## Testing
I've run a handful of rendering examples (breakout, alien_cake_addict,
auto_exposure, fog_volumes, box_shadow) and nothing broke.
## Follow-up
We should lint for the uses of `&RenderEntity` and `&MainEntity` in
queries: this is just less nice for no reason.
---------
Co-authored-by: Trashtalk217 <trashtalk217@gmail.com>
# Objective
In the Render World, there are a number of collections that are derived
from Main World entities and are used to drive rendering. The most
notable are:
- `VisibleEntities`, which is generated in the `check_visibility` system
and contains visible entities for a view.
- `ExtractedInstances`, which maps entity ids to asset ids.
In the old model, these collections were trivially kept in sync -- any
extracted phase item could look itself up because the render entity id
was guaranteed to always match the corresponding main world id.
After #15320, this became much more complicated, and was leading to a
number of subtle bugs in the Render World. The main rendering systems,
i.e. `queue_material_meshes` and `queue_material2d_meshes`, follow a
similar pattern:
```rust
for visible_entity in visible_entities.iter::<With<Mesh2d>>() {
let Some(mesh_instance) = render_mesh_instances.get_mut(visible_entity) else {
continue;
};
// Look some more stuff up and specialize the pipeline...
let bin_key = Opaque2dBinKey {
pipeline: pipeline_id,
draw_function: draw_opaque_2d,
asset_id: mesh_instance.mesh_asset_id.into(),
material_bind_group_id: material_2d.get_bind_group_id().0,
};
opaque_phase.add(
bin_key,
*visible_entity,
BinnedRenderPhaseType::mesh(mesh_instance.automatic_batching),
);
}
```
In this case, `visible_entities` and `render_mesh_instances` are both
collections that are created and keyed by Main World entity ids, and so
this lookup happens to work by coincidence. However, there is a major
unintentional bug here: namely, because `visible_entities` is a
collection of Main World ids, the phase item being queued is created
with a Main World id rather than its correct Render World id.
This happens to not break mesh rendering because the render commands
used for drawing meshes do not access the `ItemQuery` parameter, but
demonstrates the confusion that is now possible: our UI phase items are
correctly being queued with Render World ids while our meshes aren't.
Additionally, this makes it very easy and error prone to use the wrong
entity id to look up things like assets. For example, if instead we
ignored visibility checks and queued our meshes via a query, we'd have
to be extra careful to use `&MainEntity` instead of the natural
`Entity`.
## Solution
Make all collections that are derived from Main World data use
`MainEntity` as their key, to ensure type safety and avoid accidentally
looking up data with the wrong entity id:
```rust
pub type MainEntityHashMap<V> = hashbrown::HashMap<MainEntity, V, EntityHash>;
```
Additionally, we make all `PhaseItem` be able to provide both their Main
and Render World ids, to allow render phase implementors maximum
flexibility as to what id should be used to look up data.
You can think of this like tracking at the type level whether something
in the Render World should use it's "primary key", i.e. entity id, or
needs to use a foreign key, i.e. `MainEntity`.
## Testing
##### TODO:
This will require extensive testing to make sure things didn't break!
Additionally, some extraction logic has become more complicated and
needs to be checked for regressions.
## Migration Guide
With the advent of the retained render world, collections that contain
references to `Entity` that are extracted into the render world have
been changed to contain `MainEntity` in order to prevent errors where a
render world entity id is used to look up an item by accident. Custom
rendering code may need to be changed to query for `&MainEntity` in
order to look up the correct item from such a collection. Additionally,
users who implement their own extraction logic for collections of main
world entity should strongly consider extracting into a different
collection that uses `MainEntity` as a key.
Additionally, render phases now require specifying both the `Entity` and
`MainEntity` for a given `PhaseItem`. Custom render phases should ensure
`MainEntity` is available when queuing a phase item.
# Objective
Fixes#15560
Fixes (most of) #15570
Currently a lot of examples (and presumably some user code) depend on
toggling certain render features by adding/removing a single component
to an entity, e.g. `SpotLight` to toggle a light. Because of the
retained render world this no longer works: Extract will add any new
components, but when it is removed the entity persists unchanged in the
render world.
## Solution
Add `SyncComponentPlugin<C: Component>` that registers
`SyncToRenderWorld` as a required component for `C`, and adds a
component hook that will clear all components from the render world
entity when `C` is removed. We add this plugin to
`ExtractComponentPlugin` which fixes most instances of the problem. For
custom extraction logic we can manually add `SyncComponentPlugin` for
that component.
We also rename `WorldSyncPlugin` to `SyncWorldPlugin` so we start a
naming convention like all the `Extract` plugins.
In this PR I also fixed a bunch of breakage related to the retained
render world, stemming from old code that assumed that `Entity` would be
the same in both worlds.
I found that using the `RenderEntity` wrapper instead of `Entity` in
data structures when referring to render world entities makes intent
much clearer, so I propose we make this an official pattern.
## Testing
Run examples like
```
cargo run --features pbr_multi_layer_material_textures --example clearcoat
cargo run --example volumetric_fog
```
and see that they work, and that toggles work correctly. But really we
should test every single example, as we might not even have caught all
the breakage yet.
---
## Migration Guide
The retained render world notes should be updated to explain this edge
case and `SyncComponentPlugin`
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Trashtalk217 <trashtalk217@gmail.com>
# Objective
UI box shadow support
Adds a new component `BoxShadow`:
```rust
pub struct BoxShadow {
/// The shadow's color
pub color: Color,
/// Horizontal offset
pub x_offset: Val,
/// Vertical offset
pub y_offset: Val,
/// Horizontal difference in size from the occluding uninode
pub spread_radius: Val,
/// Blurriness of the shadow
pub blur_radius: Val,
}
```
To use `BoxShadow`, add the component to any Bevy UI node and a shadow
will be drawn beneath that node.
Also adds a resource `BoxShadowSamples` that can be used to adjust the
shadow quality.
#### Notes
* I'm not super happy with the field names. Maybe we need a `struct Size
{ width: Val, height: Val }` type or something.
* The shader isn't very optimised but I don't see that it's too
important for now as the number of shadows being rendered is not going
to be massive most of the time. I think it's more important to get the
API and geometry correct with this PR.
* I didn't implement an inset property, it's not essential and can
easily be added in a follow up.
* Shadows are only rendered for uinodes, not for images or text.
* Batching isn't supported, it would need out-of-the-scope-of-this-pr
changes to the way the UI handles z-ordering for it to be effective.
# Showcase
```cargo run --example box_shadow -- --samples 4```
<img width="391" alt="br" src="https://github.com/user-attachments/assets/4e8add96-dc93-46e0-9e35-d995eb0943ad">
```cargo run --example box_shadow -- --samples 10```
<img width="391" alt="s10"
src="https://github.com/user-attachments/assets/ecb384c9-4012-4cd6-9dea-5180904bf28e">
