I just implemented this to record a video for the new blog post, but I
figured it would also make a good dedicated example. This also allows us
to remove a lot of code from the 2d/3d gizmo examples since it
supersedes this portion of code.
Depends on: https://github.com/bevyengine/bevy/pull/11699
> Follow up to #10588
> Closes#11749 (Supersedes #11756)
Enable Texture slicing for the following UI nodes:
- `ImageBundle`
- `ButtonBundle`
<img width="739" alt="Screenshot 2024-01-29 at 13 57 43"
src="https://github.com/bevyengine/bevy/assets/26703856/37675681-74eb-4689-ab42-024310cf3134">
I also added a collection of `fantazy-ui-borders` from
[Kenney's](www.kenney.nl) assets, with the appropriate license (CC).
If it's a problem I can use the same textures as the `sprite_slice`
example
# Work done
Added the `ImageScaleMode` component to the targetted bundles, most of
the logic is directly reused from `bevy_sprite`.
The only additional internal component is the UI specific
`ComputedSlices`, which does the same thing as its spritee equivalent
but adapted to UI code.
Again the slicing is not compatible with `TextureAtlas`, it's something
I need to tackle more deeply in the future
# Fixes
* [x] I noticed that `TextureSlicer::compute_slices` could infinitely
loop if the border was larger that the image half extents, now an error
is triggered and the texture will fallback to being stretched
* [x] I noticed that when using small textures with very small *tiling*
options we could generate hundred of thousands of slices. Now I set a
minimum size of 1 pixel per slice, which is already ridiculously small,
and a warning will be sent at runtime when slice count goes above 1000
* [x] Sprite slicing with `flip_x` or `flip_y` would give incorrect
results, correct flipping is now supported to both sprites and ui image
nodes thanks to @odecay observation
# GPU Alternative
I create a separate branch attempting to implementing 9 slicing and
tiling directly through the `ui.wgsl` fragment shader. It works but
requires sending more data to the GPU:
- slice border
- tiling factors
And more importantly, the actual quad *scale* which is hard to put in
the shader with the current code, so that would be for a later iteration
# Objective
Bevy could benefit from *irradiance volumes*, also known as *voxel
global illumination* or simply as light probes (though this term is not
preferred, as multiple techniques can be called light probes).
Irradiance volumes are a form of baked global illumination; they work by
sampling the light at the centers of each voxel within a cuboid. At
runtime, the voxels surrounding the fragment center are sampled and
interpolated to produce indirect diffuse illumination.
## Solution
This is divided into two sections. The first is copied and pasted from
the irradiance volume module documentation and describes the technique.
The second part consists of notes on the implementation.
### Overview
An *irradiance volume* is a cuboid voxel region consisting of
regularly-spaced precomputed samples of diffuse indirect light. They're
ideal if you have a dynamic object such as a character that can move
about
static non-moving geometry such as a level in a game, and you want that
dynamic object to be affected by the light bouncing off that static
geometry.
To use irradiance volumes, you need to precompute, or *bake*, the
indirect
light in your scene. Bevy doesn't currently come with a way to do this.
Fortunately, [Blender] provides a [baking tool] as part of the Eevee
renderer, and its irradiance volumes are compatible with those used by
Bevy.
The [`bevy-baked-gi`] project provides a tool, `export-blender-gi`, that
can
extract the baked irradiance volumes from the Blender `.blend` file and
package them up into a `.ktx2` texture for use by the engine. See the
documentation in the `bevy-baked-gi` project for more details as to this
workflow.
Like all light probes in Bevy, irradiance volumes are 1×1×1 cubes that
can
be arbitrarily scaled, rotated, and positioned in a scene with the
[`bevy_transform::components::Transform`] component. The 3D voxel grid
will
be stretched to fill the interior of the cube, and the illumination from
the
irradiance volume will apply to all fragments within that bounding
region.
Bevy's irradiance volumes are based on Valve's [*ambient cubes*] as used
in
*Half-Life 2* ([Mitchell 2006], slide 27). These encode a single color
of
light from the six 3D cardinal directions and blend the sides together
according to the surface normal.
The primary reason for choosing ambient cubes is to match Blender, so
that
its Eevee renderer can be used for baking. However, they also have some
advantages over the common second-order spherical harmonics approach:
ambient cubes don't suffer from ringing artifacts, they are smaller (6
colors for ambient cubes as opposed to 9 for spherical harmonics), and
evaluation is faster. A smaller basis allows for a denser grid of voxels
with the same storage requirements.
If you wish to use a tool other than `export-blender-gi` to produce the
irradiance volumes, you'll need to pack the irradiance volumes in the
following format. The irradiance volume of resolution *(Rx, Ry, Rz)* is
expected to be a 3D texture of dimensions *(Rx, 2Ry, 3Rz)*. The
unnormalized
texture coordinate *(s, t, p)* of the voxel at coordinate *(x, y, z)*
with
side *S* ∈ *{-X, +X, -Y, +Y, -Z, +Z}* is as follows:
```text
s = x
t = y + ⎰ 0 if S ∈ {-X, -Y, -Z}
⎱ Ry if S ∈ {+X, +Y, +Z}
⎧ 0 if S ∈ {-X, +X}
p = z + ⎨ Rz if S ∈ {-Y, +Y}
⎩ 2Rz if S ∈ {-Z, +Z}
```
Visually, in a left-handed coordinate system with Y up, viewed from the
right, the 3D texture looks like a stacked series of voxel grids, one
for
each cube side, in this order:
| **+X** | **+Y** | **+Z** |
| ------ | ------ | ------ |
| **-X** | **-Y** | **-Z** |
A terminology note: Other engines may refer to irradiance volumes as
*voxel
global illumination*, *VXGI*, or simply as *light probes*. Sometimes
*light
probe* refers to what Bevy calls a reflection probe. In Bevy, *light
probe*
is a generic term that encompasses all cuboid bounding regions that
capture
indirect illumination, whether based on voxels or not.
Note that, if binding arrays aren't supported (e.g. on WebGPU or WebGL
2),
then only the closest irradiance volume to the view will be taken into
account during rendering.
[*ambient cubes*]:
https://advances.realtimerendering.com/s2006/Mitchell-ShadingInValvesSourceEngine.pdf
[Mitchell 2006]:
https://advances.realtimerendering.com/s2006/Mitchell-ShadingInValvesSourceEngine.pdf
[Blender]: http://blender.org/
[baking tool]:
https://docs.blender.org/manual/en/latest/render/eevee/render_settings/indirect_lighting.html
[`bevy-baked-gi`]: https://github.com/pcwalton/bevy-baked-gi
### Implementation notes
This patch generalizes light probes so as to reuse as much code as
possible between irradiance volumes and the existing reflection probes.
This approach was chosen because both techniques share numerous
similarities:
1. Both irradiance volumes and reflection probes are cuboid bounding
regions.
2. Both are responsible for providing baked indirect light.
3. Both techniques involve presenting a variable number of textures to
the shader from which indirect light is sampled. (In the current
implementation, this uses binding arrays.)
4. Both irradiance volumes and reflection probes require gathering and
sorting probes by distance on CPU.
5. Both techniques require the GPU to search through a list of bounding
regions.
6. Both will eventually want to have falloff so that we can smoothly
blend as objects enter and exit the probes' influence ranges. (This is
not implemented yet to keep this patch relatively small and reviewable.)
To do this, we generalize most of the methods in the reflection probes
patch #11366 to be generic over a trait, `LightProbeComponent`. This
trait is implemented by both `EnvironmentMapLight` (for reflection
probes) and `IrradianceVolume` (for irradiance volumes). Using a trait
will allow us to add more types of light probes in the future. In
particular, I highly suspect we will want real-time reflection planes
for mirrors in the future, which can be easily slotted into this
framework.
## Changelog
> This section is optional. If this was a trivial fix, or has no
externally-visible impact, you can delete this section.
### Added
* A new `IrradianceVolume` asset type is available for baked voxelized
light probes. You can bake the global illumination using Blender or
another tool of your choice and use it in Bevy to apply indirect
illumination to dynamic objects.
# Objective
Currently the `missing_docs` lint is allowed-by-default and enabled at
crate level when their documentations is complete (see #3492).
This PR proposes to inverse this logic by making `missing_docs`
warn-by-default and mark crates with imcomplete docs allowed.
## Solution
Makes `missing_docs` warn at workspace level and allowed at crate level
when the docs is imcomplete.
# Objective
- Create an example for bounding volumes and intersection tests
## Solution
- Add an example with a few bounding volumes, created from primitives
- Allow the user to cycle trough the different intersection tests
# Objective
Add interactive system debugging capabilities to bevy, providing
step/break/continue style capabilities to running system schedules.
* Original implementation: #8063
- `ignore_stepping()` everywhere was too much complexity
* Schedule-config & Resource discussion: #8168
- Decided on selective adding of Schedules & Resource-based control
## Solution
Created `Stepping` Resource. This resource can be used to enable
stepping on a per-schedule basis. Systems within schedules can be
individually configured to:
* AlwaysRun: Ignore any stepping state and run every frame
* NeverRun: Never run while stepping is enabled
- this allows for disabling of systems while debugging
* Break: If we're running the full frame, stop before this system is run
Stepping provides two modes of execution that reflect traditional
debuggers:
* Step-based: Only execute one system at a time
* Continue/Break: Run all systems, but stop before running a system
marked as Break
### Demo
https://user-images.githubusercontent.com/857742/233630981-99f3bbda-9ca6-4cc4-a00f-171c4946dc47.mov
Breakout has been modified to use Stepping. The game runs normally for a
couple of seconds, then stepping is enabled and the game appears to
pause. A list of Schedules & Systems appears with a cursor at the first
System in the list. The demo then steps forward full frames using the
spacebar until the ball is about to hit a brick. Then we step system by
system as the ball impacts a brick, showing the cursor moving through
the individual systems. Finally the demo switches back to frame stepping
as the ball changes course.
### Limitations
Due to architectural constraints in bevy, there are some cases systems
stepping will not function as a user would expect.
#### Event-driven systems
Stepping does not support systems that are driven by `Event`s as events
are flushed after 1-2 frames. Although game systems are not running
while stepping, ignored systems are still running every frame, so events
will be flushed.
This presents to the user as stepping the event-driven system never
executes the system. It does execute, but the events have already been
flushed.
This can be resolved by changing event handling to use a buffer for
events, and only dropping an event once all readers have read it.
The work-around to allow these systems to properly execute during
stepping is to have them ignore stepping:
`app.add_systems(event_driven_system.ignore_stepping())`. This was done
in the breakout example to ensure sound played even while stepping.
#### Conditional Systems
When a system is stepped, it is given an opportunity to run. If the
conditions of the system say it should not run, it will not.
Similar to Event-driven systems, if a system is conditional, and that
condition is only true for a very small time window, then stepping the
system may not execute the system. This includes depending on any sort
of external clock.
This exhibits to the user as the system not always running when it is
stepped.
A solution to this limitation is to ensure any conditions are consistent
while stepping is enabled. For example, all systems that modify any
state the condition uses should also enable stepping.
#### State-transition Systems
Stepping is configured on the per-`Schedule` level, requiring the user
to have a `ScheduleLabel`.
To support state-transition systems, bevy generates needed schedules
dynamically. Currently it’s very difficult (if not impossible, I haven’t
verified) for the user to get the labels for these schedules.
Without ready access to the dynamically generated schedules, and a
resolution for the `Event` lifetime, **stepping of the state-transition
systems is not supported**
---
## Changelog
- `Schedule::run()` updated to consult `Stepping` Resource to determine
which Systems to run each frame
- Added `Schedule.label` as a `BoxedSystemLabel`, along with supporting
`Schedule::set_label()` and `Schedule::label()` methods
- `Stepping` needed to know which `Schedule` was running, and prior to
this PR, `Schedule` didn't track its own label
- Would have preferred to add `Schedule::with_label()` and remove
`Schedule::new()`, but this PR touches enough already
- Added calls to `Schedule.set_label()` to `App` and `World` as needed
- Added `Stepping` resource
- Added `Stepping::begin_frame()` system to `MainSchedulePlugin`
- Run before `Main::run_main()`
- Notifies any `Stepping` Resource a new render frame is starting
## Migration Guide
- Add a call to `Schedule::set_label()` for any custom `Schedule`
- This is only required if the `Schedule` will be stepped
---------
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
The first part of #10569, split up from #11007.
The goal is to implement meshing support for Bevy's new geometric
primitives, starting with 2D primitives. 3D meshing will be added in a
follow-up, and we can consider removing the old mesh shapes completely.
## Solution
Add a `Meshable` trait that primitives need to implement to support
meshing, as suggested by the
[RFC](https://github.com/bevyengine/rfcs/blob/main/rfcs/12-primitive-shapes.md#meshing).
```rust
/// A trait for shapes that can be turned into a [`Mesh`].
pub trait Meshable {
/// The output of [`Self::mesh`]. This can either be a [`Mesh`]
/// or a builder used for creating a [`Mesh`].
type Output;
/// Creates a [`Mesh`] for a shape.
fn mesh(&self) -> Self::Output;
}
```
This PR implements it for the following primitives:
- `Circle`
- `Ellipse`
- `Rectangle`
- `RegularPolygon`
- `Triangle2d`
The `mesh` method typically returns a builder-like struct such as
`CircleMeshBuilder`. This is needed to support shape-specific
configuration for things like mesh resolution or UV configuration:
```rust
meshes.add(Circle { radius: 0.5 }.mesh().resolution(64));
```
Note that if no configuration is needed, you can even skip calling
`mesh` because `From<MyPrimitive>` is implemented for `Mesh`:
```rust
meshes.add(Circle { radius: 0.5 });
```
I also updated the `2d_shapes` example to use primitives, and tweaked
the colors to have better contrast against the dark background.
Before:
After:
Here you can see the UVs and different facing directions: (taken from
#11007, so excuse the 3D primitives at the bottom left)
---
## Changelog
- Added `bevy_render::mesh::primitives` module
- Added `Meshable` trait and implemented it for:
- `Circle`
- `Ellipse`
- `Rectangle`
- `RegularPolygon`
- `Triangle2d`
- Implemented `Default` and `Copy` for several 2D primitives
- Updated `2d_shapes` example to use primitives
- Tweaked colors in `2d_shapes` example to have better contrast against
the (new-ish) dark background
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
- Sending and receiving events of the same type in the same system is a
reasonably common need, generally due to event filtering.
- However, actually doing so is non-trivial, as the borrow checker
simultaneous hates mutable and immutable access.
## Solution
- Demonstrate two sensible patterns for doing so.
- Update the `ManualEventReader` docs to be more clear and link to this
example.
---------
Co-authored-by: Alice Cecile <alice.i.cecil@gmail.com>
Co-authored-by: Joona Aalto <jondolf.dev@gmail.com>
Co-authored-by: ickk <git@ickk.io>
# Objective
Keep core dependencies up to date.
## Solution
Update the dependencies.
wgpu 0.19 only supports raw-window-handle (rwh) 0.6, so bumping that was
included in this.
The rwh 0.6 version bump is just the simplest way of doing it. There
might be a way we can take advantage of wgpu's new safe surface creation
api, but I'm not familiar enough with bevy's window management to
untangle it and my attempt ended up being a mess of lifetimes and rustc
complaining about missing trait impls (that were implemented). Thanks to
@MiniaczQ for the (much simpler) rwh 0.6 version bump code.
Unblocks https://github.com/bevyengine/bevy/pull/9172 and
https://github.com/bevyengine/bevy/pull/10812
~~This might be blocked on cpal and oboe updating their ndk versions to
0.8, as they both currently target ndk 0.7 which uses rwh 0.5.2~~ Tested
on android, and everything seems to work correctly (audio properly stops
when minimized, and plays when re-focusing the app).
---
## Changelog
- `wgpu` has been updated to 0.19! The long awaited arcanization has
been merged (for more info, see
https://gfx-rs.github.io/2023/11/24/arcanization.html), and Vulkan
should now be working again on Intel GPUs.
- Targeting WebGPU now requires that you add the new `webgpu` feature
(setting the `RUSTFLAGS` environment variable to
`--cfg=web_sys_unstable_apis` is still required). This feature currently
overrides the `webgl2` feature if you have both enabled (the `webgl2`
feature is enabled by default), so it is not recommended to add it as a
default feature to libraries without putting it behind a flag that
allows library users to opt out of it! In the future we plan on
supporting wasm binaries that can target both webgl2 and webgpu now that
wgpu added support for doing so (see
https://github.com/bevyengine/bevy/issues/11505).
- `raw-window-handle` has been updated to version 0.6.
## Migration Guide
- `bevy_render::instance_index::get_instance_index()` has been removed
as the webgl2 workaround is no longer required as it was fixed upstream
in wgpu. The `BASE_INSTANCE_WORKAROUND` shaderdef has also been removed.
- WebGPU now requires the new `webgpu` feature to be enabled. The
`webgpu` feature currently overrides the `webgl2` feature so you no
longer need to disable all default features and re-add them all when
targeting `webgpu`, but binaries built with both the `webgpu` and
`webgl2` features will only target the webgpu backend, and will only
work on browsers that support WebGPU.
- Places where you conditionally compiled things for webgl2 need to be
updated because of this change, eg:
- `#[cfg(any(not(feature = "webgl"), not(target_arch = "wasm32")))]`
becomes `#[cfg(any(not(feature = "webgl") ,not(target_arch = "wasm32"),
feature = "webgpu"))]`
- `#[cfg(all(feature = "webgl", target_arch = "wasm32"))]` becomes
`#[cfg(all(feature = "webgl", target_arch = "wasm32", not(feature =
"webgpu")))]`
- `if cfg!(all(feature = "webgl", target_arch = "wasm32"))` becomes `if
cfg!(all(feature = "webgl", target_arch = "wasm32", not(feature =
"webgpu")))`
- `create_texture_with_data` now also takes a `TextureDataOrder`. You
can probably just set this to `TextureDataOrder::default()`
- `TextureFormat`'s `block_size` has been renamed to `block_copy_size`
- See the `wgpu` changelog for anything I might've missed:
https://github.com/gfx-rs/wgpu/blob/trunk/CHANGELOG.md
---------
Co-authored-by: François <mockersf@gmail.com>
# Objective
- Fixes#11516
## Solution
- Add Animated Material example (colors are hue-cycling smoothly
per-mesh)
Note: this example reproduces the perf issue found in #10610 pretty
consistently, with and without the changes from that PR included. Frame
time is sometimes around 4.3ms, other times around 12-14ms. Its pretty
random per run. I think this clears #10610 for merge.
# Objective
Fixes#11411
## Solution
- Added a simple example how to create and configure custom schedules
that are run by the `Main` schedule.
- Spot checked some of the API docs used, fixed `App::add_schedule` docs
that referred to a function argument that was removed by #9600.
## Open Questions
- While spot checking the docs, I noticed that the `Schedule` label is
stored in a field called `name` instead of `label`. This seems
unintuitive since the term label is used everywhere else. Should we
change that field name? It was introduced in #9600. If so, I do think
this change would be out of scope for this PR that mainly adds the
example.
# Objective
- Since https://github.com/bevyengine/bevy/pull/11366, feature `glsl` of
`naga_oil` is not enabled by default
- It is needed for example `shader_material_glsl`
```
thread 'Compute Task Pool (0)' panicked at crates\bevy_render\src\render_resource\shader.rs:238:35:
GLSL is not supported in this configuration; use the feature `shader_format_glsl`
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
Encountered a panic in system `bevy_render::render_resource::pipeline_cache::PipelineCache::process_pipeline_queue_system`!
thread 'main' panicked at crates\bevy_render\src\pipelined_rendering.rs:145:45:
called `Result::unwrap()` on an `Err` value: RecvError
```
## Solution
- Add feature `shader_format_glsl` as a required feature for example
`shader_material_glsl`
This pull request re-submits #10057, which was backed out for breaking
macOS, iOS, and Android. I've tested this version on macOS and Android
and on the iOS simulator.
# Objective
This pull request implements *reflection probes*, which generalize
environment maps to allow for multiple environment maps in the same
scene, each of which has an axis-aligned bounding box. This is a
standard feature of physically-based renderers and was inspired by [the
corresponding feature in Blender's Eevee renderer].
## Solution
This is a minimal implementation of reflection probes that allows
artists to define cuboid bounding regions associated with environment
maps. For every view, on every frame, a system builds up a list of the
nearest 4 reflection probes that are within the view's frustum and
supplies that list to the shader. The PBR fragment shader searches
through the list, finds the first containing reflection probe, and uses
it for indirect lighting, falling back to the view's environment map if
none is found. Both forward and deferred renderers are fully supported.
A reflection probe is an entity with a pair of components, *LightProbe*
and *EnvironmentMapLight* (as well as the standard *SpatialBundle*, to
position it in the world). The *LightProbe* component (along with the
*Transform*) defines the bounding region, while the
*EnvironmentMapLight* component specifies the associated diffuse and
specular cubemaps.
A frequent question is "why two components instead of just one?" The
advantages of this setup are:
1. It's readily extensible to other types of light probes, in particular
*irradiance volumes* (also known as ambient cubes or voxel global
illumination), which use the same approach of bounding cuboids. With a
single component that applies to both reflection probes and irradiance
volumes, we can share the logic that implements falloff and blending
between multiple light probes between both of those features.
2. It reduces duplication between the existing *EnvironmentMapLight* and
these new reflection probes. Systems can treat environment maps attached
to cameras the same way they treat environment maps applied to
reflection probes if they wish.
Internally, we gather up all environment maps in the scene and place
them in a cubemap array. At present, this means that all environment
maps must have the same size, mipmap count, and texture format. A
warning is emitted if this restriction is violated. We could potentially
relax this in the future as part of the automatic mipmap generation
work, which could easily do texture format conversion as part of its
preprocessing.
An easy way to generate reflection probe cubemaps is to bake them in
Blender and use the `export-blender-gi` tool that's part of the
[`bevy-baked-gi`] project. This tool takes a `.blend` file containing
baked cubemaps as input and exports cubemap images, pre-filtered with an
embedded fork of the [glTF IBL Sampler], alongside a corresponding
`.scn.ron` file that the scene spawner can use to recreate the
reflection probes.
Note that this is intentionally a minimal implementation, to aid
reviewability. Known issues are:
* Reflection probes are basically unsupported on WebGL 2, because WebGL
2 has no cubemap arrays. (Strictly speaking, you can have precisely one
reflection probe in the scene if you have no other cubemaps anywhere,
but this isn't very useful.)
* Reflection probes have no falloff, so reflections will abruptly change
when objects move from one bounding region to another.
* As mentioned before, all cubemaps in the world of a given type
(diffuse or specular) must have the same size, format, and mipmap count.
Future work includes:
* Blending between multiple reflection probes.
* A falloff/fade-out region so that reflected objects disappear
gradually instead of vanishing all at once.
* Irradiance volumes for voxel-based global illumination. This should
reuse much of the reflection probe logic, as they're both GI techniques
based on cuboid bounding regions.
* Support for WebGL 2, by breaking batches when reflection probes are
used.
These issues notwithstanding, I think it's best to land this with
roughly the current set of functionality, because this patch is useful
as is and adding everything above would make the pull request
significantly larger and harder to review.
---
## Changelog
### Added
* A new *LightProbe* component is available that specifies a bounding
region that an *EnvironmentMapLight* applies to. The combination of a
*LightProbe* and an *EnvironmentMapLight* offers *reflection probe*
functionality similar to that available in other engines.
[the corresponding feature in Blender's Eevee renderer]:
https://docs.blender.org/manual/en/latest/render/eevee/light_probes/reflection_cubemaps.html
[`bevy-baked-gi`]: https://github.com/pcwalton/bevy-baked-gi
[glTF IBL Sampler]: https://github.com/KhronosGroup/glTF-IBL-Sampler
# Objective
Expand the existing `Query` API to support more dynamic use cases i.e.
scripting.
## Prior Art
- #6390
- #8308
- #10037
## Solution
- Create a `QueryBuilder` with runtime methods to define the set of
component accesses for a built query.
- Create new `WorldQueryData` implementations `FilteredEntityMut` and
`FilteredEntityRef` as variants of `EntityMut` and `EntityRef` that
provide run time checked access to the components included in a given
query.
- Add new methods to `Query` to create "query lens" with a subset of the
access of the initial query.
### Query Builder
The `QueryBuilder` API allows you to define a query at runtime. At it's
most basic use it will simply create a query with the corresponding type
signature:
```rust
let query = QueryBuilder::<Entity, With<A>>::new(&mut world).build();
// is equivalent to
let query = QueryState::<Entity, With<A>>::new(&mut world);
```
Before calling `.build()` you also have the opportunity to add
additional accesses and filters. Here is a simple example where we add
additional filter terms:
```rust
let entity_a = world.spawn((A(0), B(0))).id();
let entity_b = world.spawn((A(0), C(0))).id();
let mut query_a = QueryBuilder::<Entity>::new(&mut world)
.with::<A>()
.without::<C>()
.build();
assert_eq!(entity_a, query_a.single(&world));
```
This alone is useful in that allows you to decide which archetypes your
query will match at runtime. However it is also very limited, consider a
case like the following:
```rust
let query_a = QueryBuilder::<&A>::new(&mut world)
// Add an additional access
.data::<&B>()
.build();
```
This will grant the query an additional read access to component B
however we have no way of accessing the data while iterating as the type
signature still only includes &A. For an even more concrete example of
this consider dynamic components:
```rust
let query_a = QueryBuilder::<Entity>::new(&mut world)
// Adding a filter is easy since it doesn't need be read later
.with_id(component_id_a)
// How do I access the data of this component?
.ref_id(component_id_b)
.build();
```
With this in mind the `QueryBuilder` API seems somewhat incomplete by
itself, we need some way method of accessing the components dynamically.
So here's one:
### Query Transmutation
If the problem is not having the component in the type signature why not
just add it? This PR also adds transmute methods to `QueryBuilder` and
`QueryState`. Here's a simple example:
```rust
world.spawn(A(0));
world.spawn((A(1), B(0)));
let mut query = QueryBuilder::<()>::new(&mut world)
.with::<B>()
.transmute::<&A>()
.build();
query.iter(&world).for_each(|a| assert_eq!(a.0, 1));
```
The `QueryState` and `QueryBuilder` transmute methods look quite similar
but are different in one respect. Transmuting a builder will always
succeed as it will just add the additional accesses needed for the new
terms if they weren't already included. Transmuting a `QueryState` will
panic in the case that the new type signature would give it access it
didn't already have, for example:
```rust
let query = QueryState::<&A, Option<&B>>::new(&mut world);
/// This is fine, the access for Option<&A> is less restrictive than &A
query.transmute::<Option<&A>>(&world);
/// Oh no, this would allow access to &B on entities that might not have it, so it panics
query.transmute::<&B>(&world);
/// This is right out
query.transmute::<&C>(&world);
```
This is quite an appealing API to also have available on `Query` however
it does pose one additional wrinkle: In order to to change the iterator
we need to create a new `QueryState` to back it. `Query` doesn't own
it's own state though, it just borrows it, so we need a place to borrow
it from. This is why `QueryLens` exists, it is a place to store the new
state so it can be borrowed when you call `.query()` leaving you with an
API like this:
```rust
fn function_that_takes_a_query(query: &Query<&A>) {
// ...
}
fn system(query: Query<(&A, &B)>) {
let lens = query.transmute_lens::<&A>();
let q = lens.query();
function_that_takes_a_query(&q);
}
```
Now you may be thinking: Hey, wait a second, you introduced the problem
with dynamic components and then described a solution that only works
for static components! Ok, you got me, I guess we need a bit more:
### Filtered Entity References
Currently the only way you can access dynamic components on entities
through a query is with either `EntityMut` or `EntityRef`, however these
can access all components and so conflict with all other accesses. This
PR introduces `FilteredEntityMut` and `FilteredEntityRef` as
alternatives that have additional runtime checking to prevent accessing
components that you shouldn't. This way you can build a query with a
`QueryBuilder` and actually access the components you asked for:
```rust
let mut query = QueryBuilder::<FilteredEntityRef>::new(&mut world)
.ref_id(component_id_a)
.with(component_id_b)
.build();
let entity_ref = query.single(&world);
// Returns Some(Ptr) as we have that component and are allowed to read it
let a = entity_ref.get_by_id(component_id_a);
// Will return None even though the entity does have the component, as we are not allowed to read it
let b = entity_ref.get_by_id(component_id_b);
```
For the most part these new structs have the exact same methods as their
non-filtered equivalents.
Putting all of this together we can do some truly dynamic ECS queries,
check out the `dynamic` example to see it in action:
```
Commands:
comp, c Create new components
spawn, s Spawn entities
query, q Query for entities
Enter a command with no parameters for usage.
> c A, B, C, Data 4
Component A created with id: 0
Component B created with id: 1
Component C created with id: 2
Component Data created with id: 3
> s A, B, Data 1
Entity spawned with id: 0v0
> s A, C, Data 0
Entity spawned with id: 1v0
> q &Data
0v0: Data: [1, 0, 0, 0]
1v0: Data: [0, 0, 0, 0]
> q B, &mut Data
0v0: Data: [2, 1, 1, 1]
> q B || C, &Data
0v0: Data: [2, 1, 1, 1]
1v0: Data: [0, 0, 0, 0]
```
## Changelog
- Add new `transmute_lens` methods to `Query`.
- Add new types `QueryBuilder`, `FilteredEntityMut`, `FilteredEntityRef`
and `QueryLens`
- `update_archetype_component_access` has been removed, archetype
component accesses are now determined by the accesses set in
`update_component_access`
- Added method `set_access` to `WorldQuery`, this is called before
`update_component_access` for queries that have a restricted set of
accesses, such as those built by `QueryBuilder` or `QueryLens`. This is
primarily used by the `FilteredEntity*` variants and has an empty trait
implementation.
- Added method `get_state` to `WorldQuery` as a fallible version of
`init_state` when you don't have `&mut World` access.
## Future Work
Improve performance of `FilteredEntityMut` and `FilteredEntityRef`,
currently they have to determine the accesses a query has in a given
archetype during iteration which is far from ideal, especially since we
already did the work when matching the archetype in the first place. To
avoid making more internal API changes I have left it out of this PR.
---------
Co-authored-by: Mike Hsu <mike.hsu@gmail.com>
# Objective
Add support for presenting each UI tree on a specific window and
viewport, while making as few breaking changes as possible.
This PR is meant to resolve the following issues at once, since they're
all related.
- Fixes#5622
- Fixes#5570
- Fixes#5621
Adopted #5892 , but started over since the current codebase diverged
significantly from the original PR branch. Also, I made a decision to
propagate component to children instead of recursively iterating over
nodes in search for the root.
## Solution
Add a new optional component that can be inserted to UI root nodes and
propagate to children to specify which camera it should render onto.
This is then used to get the render target and the viewport for that UI
tree. Since this component is optional, the default behavior should be
to render onto the single camera (if only one exist) and warn of
ambiguity if multiple cameras exist. This reduces the complexity for
users with just one camera, while giving control in contexts where it
matters.
## Changelog
- Adds `TargetCamera(Entity)` component to specify which camera should a
node tree be rendered into. If only one camera exists, this component is
optional.
- Adds an example of rendering UI to a texture and using it as a
material in a 3D world.
- Fixes recalculation of physical viewport size when target scale factor
changes. This can happen when the window is moved between displays with
different DPI.
- Changes examples to demonstrate assigning UI to different viewports
and windows and make interactions in an offset viewport testable.
- Removes `UiCameraConfig`. UI visibility now can be controlled via
combination of explicit `TargetCamera` and `Visibility` on the root
nodes.
---------
Co-authored-by: davier <bricedavier@gmail.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Alice Cecile <alice.i.cecil@gmail.com>
> Replaces #5213
# Objective
Implement sprite tiling and [9 slice
scaling](https://en.wikipedia.org/wiki/9-slice_scaling) for
`bevy_sprite`.
Allowing slice scaling and texture tiling.
Basic scaling vs 9 slice scaling:
Slicing example:
<img width="481" alt="Screenshot 2022-07-05 at 15 05 49"
src="https://user-images.githubusercontent.com/26703856/177336112-9e961af0-c0af-4197-aec9-430c1170a79d.png">
Tiling example:
<img width="1329" alt="Screenshot 2023-11-16 at 13 53 32"
src="https://github.com/bevyengine/bevy/assets/26703856/14db39b7-d9e0-4bc3-ba0e-b1f2db39ae8f">
# Solution
- `SpriteBundlue` now has a `scale_mode` component storing a
`SpriteScaleMode` enum with three variants:
- `Stretched` (default)
- `Tiled` to have sprites tile horizontally and/or vertically
- `Sliced` allowing 9 slicing the texture and optionally tile some
sections with a `Textureslicer`.
- `bevy_sprite` has two extra systems to compute a
`ComputedTextureSlices` if necessary,:
- One system react to changes on `Sprite`, `Handle<Image>` or
`SpriteScaleMode`
- The other listens to `AssetEvent<Image>` to compute slices on sprites
when the texture is ready or changed
- I updated the `bevy_sprite` extraction stage to extract potentially
multiple textures instead of one, depending on the presence of
`ComputedTextureSlices`
- I added two examples showcasing the slicing and tiling feature.
The addition of `ComputedTextureSlices` as a cache is to avoid querying
the image data, to retrieve its dimensions, every frame in a extract or
prepare stage. Also it reacts to changes so we can have stuff like this
(tiling example):
https://github.com/bevyengine/bevy/assets/26703856/a349a9f3-33c3-471f-8ef4-a0e5dfce3b01
# Related
- [ ] Once #5103 or #10099 is merged I can enable tiling and slicing for
texture sheets as ui
# To discuss
There is an other option, to consider slice/tiling as part of the asset,
using the new asset preprocessing but I have no clue on how to do it.
Also, instead of retrieving the Image dimensions, we could use the same
system as the sprite sheet and have the user give the image dimensions
directly (grid). But I think it's less user friendly
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: ickshonpe <david.curthoys@googlemail.com>
Co-authored-by: Alice Cecile <alice.i.cecil@gmail.com>
# Objective
This PR is heavily inspired by
https://github.com/bevyengine/bevy/pull/7682
It aims to solve the same problem: allowing the user to extend the
tracing subscriber with extra layers.
(in my case, I'd like to use `use
metrics_tracing_context::{MetricsLayer, TracingContextLayer};`)
## Solution
I'm proposing a different api where the user has the opportunity to take
the existing `subscriber` and apply any transformations on it.
---
## Changelog
- Added a `update_subscriber` option on the `LogPlugin` that lets the
user modify the `subscriber` (for example to extend it with more tracing
`Layers`
## Migration Guide
> This section is optional. If there are no breaking changes, you can
delete this section.
- Added a new field `update_subscriber` in the `LogPlugin`
---------
Co-authored-by: Charles Bournhonesque <cbournhonesque@snapchat.com>
# Objective
Issue #10243: rendering multiple triangles in the same place results in
flickering.
## Solution
Considered these alternatives:
- `depth_bias` may not work, because of high number of entities, so
creating a material per entity is practically not possible
- rendering at slightly different positions does not work, because when
camera is far, float rounding causes the same issues (edit: assuming we
have to use the same `depth_bias`)
- considered implementing deterministic operation like
`query.par_iter().flat_map(...).collect()` to be used in
`check_visibility` system (which would solve the issue since query is
deterministic), and could not figure out how to make it as cheap as
current approach with thread-local collectors (#11249)
So adding an option to sort entities after `check_visibility` system
run.
Should not be too bad, because after visibility check, only a handful
entities remain.
This is probably not the only source of non-determinism in Bevy, but
this is one I could find so far. At least it fixes the repro example.
## Changelog
- `DeterministicRenderingConfig` option to enable deterministic
rendering
## Test
<img width="1392" alt="image"
src="https://github.com/bevyengine/bevy/assets/28969/c735bce1-3a71-44cd-8677-c19f6c0ee6bd">
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Re this comment:
https://github.com/bevyengine/bevy/pull/11141#issuecomment-1872455313
Since https://github.com/bevyengine/bevy/pull/9822, Bevy automatically
inserts `apply_deferred` between systems with dependencies where needed,
so manually inserted `apply_deferred` doesn't to anything useful, and in
current state this example does more harm than good.
## Solution
The example can be modified with removal of automatic `apply_deferred`
insertion, but that would immediately upgrade this example from beginner
level, to upper intermediate. Most users don't need to disable automatic
sync point insertion, and remaining few who do probably already know how
it works.
CC @hymm
# Objective
This pull request implements *reflection probes*, which generalize
environment maps to allow for multiple environment maps in the same
scene, each of which has an axis-aligned bounding box. This is a
standard feature of physically-based renderers and was inspired by [the
corresponding feature in Blender's Eevee renderer].
## Solution
This is a minimal implementation of reflection probes that allows
artists to define cuboid bounding regions associated with environment
maps. For every view, on every frame, a system builds up a list of the
nearest 4 reflection probes that are within the view's frustum and
supplies that list to the shader. The PBR fragment shader searches
through the list, finds the first containing reflection probe, and uses
it for indirect lighting, falling back to the view's environment map if
none is found. Both forward and deferred renderers are fully supported.
A reflection probe is an entity with a pair of components, *LightProbe*
and *EnvironmentMapLight* (as well as the standard *SpatialBundle*, to
position it in the world). The *LightProbe* component (along with the
*Transform*) defines the bounding region, while the
*EnvironmentMapLight* component specifies the associated diffuse and
specular cubemaps.
A frequent question is "why two components instead of just one?" The
advantages of this setup are:
1. It's readily extensible to other types of light probes, in particular
*irradiance volumes* (also known as ambient cubes or voxel global
illumination), which use the same approach of bounding cuboids. With a
single component that applies to both reflection probes and irradiance
volumes, we can share the logic that implements falloff and blending
between multiple light probes between both of those features.
2. It reduces duplication between the existing *EnvironmentMapLight* and
these new reflection probes. Systems can treat environment maps attached
to cameras the same way they treat environment maps applied to
reflection probes if they wish.
Internally, we gather up all environment maps in the scene and place
them in a cubemap array. At present, this means that all environment
maps must have the same size, mipmap count, and texture format. A
warning is emitted if this restriction is violated. We could potentially
relax this in the future as part of the automatic mipmap generation
work, which could easily do texture format conversion as part of its
preprocessing.
An easy way to generate reflection probe cubemaps is to bake them in
Blender and use the `export-blender-gi` tool that's part of the
[`bevy-baked-gi`] project. This tool takes a `.blend` file containing
baked cubemaps as input and exports cubemap images, pre-filtered with an
embedded fork of the [glTF IBL Sampler], alongside a corresponding
`.scn.ron` file that the scene spawner can use to recreate the
reflection probes.
Note that this is intentionally a minimal implementation, to aid
reviewability. Known issues are:
* Reflection probes are basically unsupported on WebGL 2, because WebGL
2 has no cubemap arrays. (Strictly speaking, you can have precisely one
reflection probe in the scene if you have no other cubemaps anywhere,
but this isn't very useful.)
* Reflection probes have no falloff, so reflections will abruptly change
when objects move from one bounding region to another.
* As mentioned before, all cubemaps in the world of a given type
(diffuse or specular) must have the same size, format, and mipmap count.
Future work includes:
* Blending between multiple reflection probes.
* A falloff/fade-out region so that reflected objects disappear
gradually instead of vanishing all at once.
* Irradiance volumes for voxel-based global illumination. This should
reuse much of the reflection probe logic, as they're both GI techniques
based on cuboid bounding regions.
* Support for WebGL 2, by breaking batches when reflection probes are
used.
These issues notwithstanding, I think it's best to land this with
roughly the current set of functionality, because this patch is useful
as is and adding everything above would make the pull request
significantly larger and harder to review.
---
## Changelog
### Added
* A new *LightProbe* component is available that specifies a bounding
region that an *EnvironmentMapLight* applies to. The combination of a
*LightProbe* and an *EnvironmentMapLight* offers *reflection probe*
functionality similar to that available in other engines.
[the corresponding feature in Blender's Eevee renderer]:
https://docs.blender.org/manual/en/latest/render/eevee/light_probes/reflection_cubemaps.html
[`bevy-baked-gi`]: https://github.com/pcwalton/bevy-baked-gi
[glTF IBL Sampler]: https://github.com/KhronosGroup/glTF-IBL-Sampler
# Objective
Lightmaps, textures that store baked global illumination, have been a
mainstay of real-time graphics for decades. Bevy currently has no
support for them, so this pull request implements them.
## Solution
The new `Lightmap` component can be attached to any entity that contains
a `Handle<Mesh>` and a `StandardMaterial`. When present, it will be
applied in the PBR shader. Because multiple lightmaps are frequently
packed into atlases, each lightmap may have its own UV boundaries within
its texture. An `exposure` field is also provided, to control the
brightness of the lightmap.
Note that this PR doesn't provide any way to bake the lightmaps. That
can be done with [The Lightmapper] or another solution, such as Unity's
Bakery.
---
## Changelog
### Added
* A new component, `Lightmap`, is available, for baked global
illumination. If your mesh has a second UV channel (UV1), and you attach
this component to the entity with that mesh, Bevy will apply the texture
referenced in the lightmap.
[The Lightmapper]: https://github.com/Naxela/The_Lightmapper
---------
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
Provide an example of how to achieve pixel-perfect "grid snapping" in 2D
via rendering to a texture. This is a common use case in retro pixel art
game development.
## Solution
Render sprites to a canvas via a Camera, then use another (scaled up)
Camera to render the resulting canvas to the screen. This example is
based on the `3d/render_to_texture.rs` example. Furthermore, this
example demonstrates mixing retro-style graphics with high-resolution
graphics, as well as pixel-snapped rendering of a
`MaterialMesh2dBundle`.
# Objective
Related to #10612.
Enable the
[`clippy::manual_let_else`](https://rust-lang.github.io/rust-clippy/master/#manual_let_else)
lint as a warning. The `let else` form seems more idiomatic to me than a
`match`/`if else` that either match a pattern or diverge, and from the
clippy doc, the lint doesn't seem to have any possible false positive.
## Solution
Add the lint as warning in `Cargo.toml`, refactor places where the lint
triggers.
# Objective
Partially addresses #10612
After moving the initial docs_markdown warning, this is a PR that moves
the rest of the CI clippy lint definitions to the cargo.toml.
## Solution
- the `tools/ci/src/main.rs` clippy lints removed and just the warning
flag remains.
- the warnings moved to the root cargo workspace toml.
# Objective
Updates [`futures-lite`](https://github.com/smol-rs/futures-lite) in
bevy_tasks to the next major version (1 -> 2).
Also removes the duplication of `futures-lite`, as `async-fs` requires v
2, so there are currently 2 copies of futures-lite in the dependency
tree.
Futures-lite has received [a number of
updates](https://github.com/smol-rs/futures-lite/blob/master/CHANGELOG.md)
since bevy's current version `1.4`.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Mike <mike.hsu@gmail.com>
# Objective
Enables warning on `clippy::undocumented_unsafe_blocks` across the
workspace rather than only in `bevy_ecs`, `bevy_transform` and
`bevy_utils`. This adds a little awkwardness in a few areas of code that
have trivial safety or explain safety for multiple unsafe blocks with
one comment however automatically prevents these comments from being
missed.
## Solution
This adds `undocumented_unsafe_blocks = "warn"` to the workspace
`Cargo.toml` and fixes / adds a few missed safety comments. I also added
`#[allow(clippy::undocumented_unsafe_blocks)]` where the safety is
explained somewhere above.
There are a couple of safety comments I added I'm not 100% sure about in
`bevy_animation` and `bevy_render/src/view` and I'm not sure about the
use of `#[allow(clippy::undocumented_unsafe_blocks)]` compared to adding
comments like `// SAFETY: See above`.
# Objective
Partially Addresses #10612
fix: add clippy::doc_markdown linting to cargo workspace
Rather than do all the warnings in `tools/ci/src/main.rs` in one-shot,
just wanted to have an initial pr adding the first one to get the form
correct as some may trigger build errors and require changes to get
merged more easily.
## Solution
- adding the doc_markdown and removing it from the ci check as it'll now
be a build error during normal compilation.
---------
Co-authored-by: François <mockersf@gmail.com>
# Objective
- Fix adding `#![allow(clippy::type_complexity)]` everywhere. like #9796
## Solution
- Use the new [lints] table that will land in 1.74
(https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#lints)
- inherit lint to the workspace, crates and examples.
```
[lints]
workspace = true
```
## Changelog
- Bump rust version to 1.74
- Enable lints table for the workspace
```toml
[workspace.lints.clippy]
type_complexity = "allow"
```
- Allow type complexity for all crates and examples
```toml
[lints]
workspace = true
```
---------
Co-authored-by: Martín Maita <47983254+mnmaita@users.noreply.github.com>
# Objective
- Fixes#10518
## Solution
I've added a method to `LoadContext`, `load_direct_with_reader`, which
mirrors the behaviour of `load_direct` with a single key difference: it
is provided with the `Reader` by the caller, rather than getting it from
the contained `AssetServer`. This allows for an `AssetLoader` to process
its `Reader` stream, and then directly hand the results off to the
`LoadContext` to handle further loading. The outer `AssetLoader` can
control how the `Reader` is interpreted by providing a relevant
`AssetPath`.
For example, a Gzip decompression loader could process the asset
`images/my_image.png.gz` by decompressing the bytes, then handing the
decompressed result to the `LoadContext` with the new path
`images/my_image.png.gz/my_image.png`. This intuitively reflects the
nature of contained assets, whilst avoiding unintended behaviour, since
the generated path cannot be a real file path (a file and folder of the
same name cannot coexist in most file-systems).
```rust
#[derive(Asset, TypePath)]
pub struct GzAsset {
pub uncompressed: ErasedLoadedAsset,
}
#[derive(Default)]
pub struct GzAssetLoader;
impl AssetLoader for GzAssetLoader {
type Asset = GzAsset;
type Settings = ();
type Error = GzAssetLoaderError;
fn load<'a>(
&'a self,
reader: &'a mut Reader,
_settings: &'a (),
load_context: &'a mut LoadContext,
) -> BoxedFuture<'a, Result<Self::Asset, Self::Error>> {
Box::pin(async move {
let compressed_path = load_context.path();
let file_name = compressed_path
.file_name()
.ok_or(GzAssetLoaderError::IndeterminateFilePath)?
.to_string_lossy();
let uncompressed_file_name = file_name
.strip_suffix(".gz")
.ok_or(GzAssetLoaderError::IndeterminateFilePath)?;
let contained_path = compressed_path.join(uncompressed_file_name);
let mut bytes_compressed = Vec::new();
reader.read_to_end(&mut bytes_compressed).await?;
let mut decoder = GzDecoder::new(bytes_compressed.as_slice());
let mut bytes_uncompressed = Vec::new();
decoder.read_to_end(&mut bytes_uncompressed)?;
// Now that we have decompressed the asset, let's pass it back to the
// context to continue loading
let mut reader = VecReader::new(bytes_uncompressed);
let uncompressed = load_context
.load_direct_with_reader(&mut reader, contained_path)
.await?;
Ok(GzAsset { uncompressed })
})
}
fn extensions(&self) -> &[&str] {
&["gz"]
}
}
```
Because this example is so prudent, I've included an
`asset_decompression` example which implements this exact behaviour:
```rust
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.init_asset::<GzAsset>()
.init_asset_loader::<GzAssetLoader>()
.add_systems(Startup, setup)
.add_systems(Update, decompress::<Image>)
.run();
}
fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
commands.spawn(Camera2dBundle::default());
commands.spawn((
Compressed::<Image> {
compressed: asset_server.load("data/compressed_image.png.gz"),
..default()
},
Sprite::default(),
TransformBundle::default(),
VisibilityBundle::default(),
));
}
fn decompress<A: Asset>(
mut commands: Commands,
asset_server: Res<AssetServer>,
mut compressed_assets: ResMut<Assets<GzAsset>>,
query: Query<(Entity, &Compressed<A>)>,
) {
for (entity, Compressed { compressed, .. }) in query.iter() {
let Some(GzAsset { uncompressed }) = compressed_assets.remove(compressed) else {
continue;
};
let uncompressed = uncompressed.take::<A>().unwrap();
commands
.entity(entity)
.remove::<Compressed<A>>()
.insert(asset_server.add(uncompressed));
}
}
```
A key limitation to this design is how to type the internally loaded
asset, since the example `GzAssetLoader` is unaware of the internal
asset type `A`. As such, in this example I store the contained asset as
an `ErasedLoadedAsset`, and leave it up to the consumer of the `GzAsset`
to handle typing the final result, which is the purpose of the
`decompress` system. This limitation can be worked around by providing
type information to the `GzAssetLoader`, such as `GzAssetLoader<Image,
ImageAssetLoader>`, but this would require registering the asset loader
for every possible decompression target.
Aside from this limitation, nested asset containerisation works as an
end user would expect; if the user registers a `TarAssetLoader`, and a
`GzAssetLoader`, then they can load assets with compound
containerisation, such as `images.tar.gz`.
---
## Changelog
- Added `LoadContext::load_direct_with_reader`
- Added `asset_decompression` example
## Notes
- While I believe my implementation of a Gzip asset loader is
reasonable, I haven't included it as a public feature of `bevy_asset` to
keep the scope of this PR as focussed as possible.
- I have included `flate2` as a `dev-dependency` for the example; it is
not included in the main dependency graph.
# Objective
- Examples with required features fail to build
- If you're fixing a specific issue, say "Fixes #X".
## Solution
- Pass them along when building examples for wasm showcase
- Also mark example `hot_asset_reloading` as not wasm compatible as it
isn't even with the right features enabled
# Objective
- 2d materials have subtle differences with 3d materials that aren't
obvious to beginners
## Solution
- Add an example that shows how to make a 2d material
Preparing next release
This PR has been auto-generated
---------
Co-authored-by: Bevy Auto Releaser <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: François <mockersf@gmail.com>
# Objective
<img width="1920" alt="Screenshot 2023-04-26 at 01 07 34"
src="https://user-images.githubusercontent.com/418473/234467578-0f34187b-5863-4ea1-88e9-7a6bb8ce8da3.png">
This PR adds both diffuse and specular light transmission capabilities
to the `StandardMaterial`, with support for screen space refractions.
This enables realistically representing a wide range of real-world
materials, such as:
- Glass; (Including frosted glass)
- Transparent and translucent plastics;
- Various liquids and gels;
- Gemstones;
- Marble;
- Wax;
- Paper;
- Leaves;
- Porcelain.
Unlike existing support for transparency, light transmission does not
rely on fixed function alpha blending, and therefore works with both
`AlphaMode::Opaque` and `AlphaMode::Mask` materials.
## Solution
- Introduces a number of transmission related fields in the
`StandardMaterial`;
- For specular transmission:
- Adds logic to take a view main texture snapshot after the opaque
phase; (in order to perform screen space refractions)
- Introduces a new `Transmissive3d` phase to the renderer, to which all
meshes with `transmission > 0.0` materials are sent.
- Calculates a light exit point (of the approximate mesh volume) using
`ior` and `thickness` properties
- Samples the snapshot texture with an adaptive number of taps across a
`roughness`-controlled radius enabling “blurry” refractions
- For diffuse transmission:
- Approximates transmitted diffuse light by using a second, flipped +
displaced, diffuse-only Lambertian lobe for each light source.
## To Do
- [x] Figure out where `fresnel_mix()` is taking place, if at all, and
where `dielectric_specular` is being calculated, if at all, and update
them to use the `ior` value (Not a blocker, just a nice-to-have for more
correct BSDF)
- To the _best of my knowledge, this is now taking place, after
964340cdd. The fresnel mix is actually "split" into two parts in our
implementation, one `(1 - fresnel(...))` in the transmission, and
`fresnel()` in the light implementations. A surface with more
reflectance now will produce slightly dimmer transmission towards the
grazing angle, as more of the light gets reflected.
- [x] Add `transmission_texture`
- [x] Add `diffuse_transmission_texture`
- [x] Add `thickness_texture`
- [x] Add `attenuation_distance` and `attenuation_color`
- [x] Connect values to glTF loader
- [x] `transmission` and `transmission_texture`
- [x] `thickness` and `thickness_texture`
- [x] `ior`
- [ ] `diffuse_transmission` and `diffuse_transmission_texture` (needs
upstream support in `gltf` crate, not a blocker)
- [x] Add support for multiple screen space refraction “steps”
- [x] Conditionally create no transmission snapshot texture at all if
`steps == 0`
- [x] Conditionally enable/disable screen space refraction transmission
snapshots
- [x] Read from depth pre-pass to prevent refracting pixels in front of
the light exit point
- [x] Use `interleaved_gradient_noise()` function for sampling blur in a
way that benefits from TAA
- [x] Drill down a TAA `#define`, tweak some aspects of the effect
conditionally based on it
- [x] Remove const array that's crashing under HLSL (unless a new `naga`
release with https://github.com/gfx-rs/naga/pull/2496 comes out before
we merge this)
- [ ] Look into alternatives to the `switch` hack for dynamically
indexing the const array (might not be needed, compilers seem to be
decent at expanding it)
- [ ] Add pipeline keys for gating transmission (do we really want/need
this?)
- [x] Tweak some material field/function names?
## A Note on Texture Packing
_This was originally added as a comment to the
`specular_transmission_texture`, `thickness_texture` and
`diffuse_transmission_texture` documentation, I removed it since it was
more confusing than helpful, and will likely be made redundant/will need
to be updated once we have a better infrastructure for preprocessing
assets_
Due to how channels are mapped, you can more efficiently use a single
shared texture image
for configuring the following:
- R - `specular_transmission_texture`
- G - `thickness_texture`
- B - _unused_
- A - `diffuse_transmission_texture`
The `KHR_materials_diffuse_transmission` glTF extension also defines a
`diffuseTransmissionColorTexture`,
that _we don't currently support_. One might choose to pack the
intensity and color textures together,
using RGB for the color and A for the intensity, in which case this
packing advice doesn't really apply.
---
## Changelog
- Added a new `Transmissive3d` render phase for rendering specular
transmissive materials with screen space refractions
- Added rendering support for transmitted environment map light on the
`StandardMaterial` as a fallback for screen space refractions
- Added `diffuse_transmission`, `specular_transmission`, `thickness`,
`ior`, `attenuation_distance` and `attenuation_color` to the
`StandardMaterial`
- Added `diffuse_transmission_texture`, `specular_transmission_texture`,
`thickness_texture` to the `StandardMaterial`, gated behind a new
`pbr_transmission_textures` cargo feature (off by default, for maximum
hardware compatibility)
- Added `Camera3d::screen_space_specular_transmission_steps` for
controlling the number of “layers of transparency” rendered for
transmissive objects
- Added a `TransmittedShadowReceiver` component for enabling shadows in
(diffusely) transmitted light. (disabled by default, as it requires
carefully setting up the `thickness` to avoid self-shadow artifacts)
- Added support for the `KHR_materials_transmission`,
`KHR_materials_ior` and `KHR_materials_volume` glTF extensions
- Renamed items related to temporal jitter for greater consistency
## Migration Guide
- `SsaoPipelineKey::temporal_noise` has been renamed to
`SsaoPipelineKey::temporal_jitter`
- The `TAA` shader def (controlled by the presence of the
`TemporalAntiAliasSettings` component in the camera) has been replaced
with the `TEMPORAL_JITTER` shader def (controlled by the presence of the
`TemporalJitter` component in the camera)
- `MeshPipelineKey::TAA` has been replaced by
`MeshPipelineKey::TEMPORAL_JITTER`
- The `TEMPORAL_NOISE` shader def has been consolidated with
`TEMPORAL_JITTER`
# Objective
- Fixes#10133
## Solution
- Add a new example that focuses on using `Virtual` time
## Changelog
### Added
- new `virtual_time` example
### Changed
- moved `time` & `timers` examples to the new `examples/time` folder
# Objective
Make it obvious why stuff renders pink when rendering stuff with bevy
with `default_features = false` and bevy's default tonemapper
(TonyMcMapFace, it requires a LUT which requires the `tonemapping_luts`,
`ktx2`, and `zstd` features).
Not sure if this should be considered as fixing these issues, but in my
previous PR (https://github.com/bevyengine/bevy/pull/9073, and old
discussions on discord that I only somewhat remember) it seemed like we
didn't want to make ktx2 and zstd required features for
bevy_core_pipeline.
Related https://github.com/bevyengine/bevy/issues/9179
Related https://github.com/bevyengine/bevy/issues/9098
## Solution
This logs an error when a LUT based tonemapper is used without the
`tonemapping_luts` feature enabled, and cleans up the default features a
bit (`tonemapping_luts` now includes the `ktx2` and `zstd` features,
since it panics without them).
Another solution would be to fall back to a non-lut based tonemapper,
but I don't like this solution as then it's not explicitly clear to
users why eg. a library example renders differently than a normal bevy
app (if the library forgot the `tonemapping_luts` feature).
I did remove the `ktx2` and `zstd` features from the list of default
features in Cargo.toml, as I don't believe anything else currently in
bevy relies on them (or at least searching through every hit for `ktx2`
and `zstd` didn't show anything except loading an environment map in
some examples), and they still show up in the `cargo_features` doc as
default features.
---
## Changelog
- The `tonemapping_luts` feature now includes both the `ktx2` and `zstd`
features to avoid a panic when the `tonemapping_luts` feature was enable
without both the `ktx2` and `zstd` feature enabled.
# Objective
- Reduce noise to allow users to see previous asset changes and other
logs like from asset reloading
- The example file is named differently than the example
## Solution
- Only print the asset content if there are asset events
- Rename the example file to `asset_processing`
# Objective
- I want to use the `debug_glam_assert` feature with bevy.
## Solution
- Re-export the feature flag
---
## Changelog
- Re-export `debug_glam_assert` feature flag from glam.
# Objective
Users shouldn't need to change their source code between "development
workflows" and "releasing". Currently, Bevy Asset V2 has two "processed"
asset modes `Processed` (assumes assets are already processed) and
`ProcessedDev` (starts an asset processor and processes assets). This
means that the mode must be changed _in code_ when switching from "app
dev" to "release". Very suboptimal.
We have already removed "runtime opt-in" for hot-reloading. Enabling the
`file_watcher` feature _automatically_ enables file watching in code.
This means deploying a game (without hot reloading enabled) just means
calling `cargo build --release` instead of `cargo run --features
bevy/file_watcher`.
We should adopt this pattern for asset processing.
## Solution
This adds the `asset_processor` feature, which will start the
`AssetProcessor` when an `AssetPlugin` runs in `AssetMode::Processed`.
The "asset processing workflow" is now:
1. Enable `AssetMode::Processed` on `AssetPlugin`
2. When developing, run with the `asset_processor` and `file_watcher`
features
3. When releasing, build without these features.
The `AssetMode::ProcessedDev` mode has been removed.
# Objective
- Fixes#9382
## Solution
- Added a few extra notes in regards to WebGPU experimental state and
the need of enabling unstable APIs through certain attribute flags in
`cargo_features.md` and the examples `README.md` files.
# Objective
allow extending `Material`s (including the built in `StandardMaterial`)
with custom vertex/fragment shaders and additional data, to easily get
pbr lighting with custom modifications, or otherwise extend a base
material.
# Solution
- added `ExtendedMaterial<B: Material, E: MaterialExtension>` which
contains a base material and a user-defined extension.
- added example `extended_material` showing how to use it
- modified AsBindGroup to have "unprepared" functions that return raw
resources / layout entries so that the extended material can combine
them
note: doesn't currently work with array resources, as i can't figure out
how to make the OwnedBindingResource::get_binding() work, as wgpu
requires a `&'a[&'a TextureView]` and i have a `Vec<TextureView>`.
# Migration Guide
manual implementations of `AsBindGroup` will need to be adjusted, the
changes are pretty straightforward and can be seen in the diff for e.g.
the `texture_binding_array` example.
---------
Co-authored-by: Robert Swain <robert.swain@gmail.com>
# Objective
Current `FixedTime` and `Time` have several problems. This pull aims to
fix many of them at once.
- If there is a longer pause between app updates, time will jump forward
a lot at once and fixed time will iterate on `FixedUpdate` for a large
number of steps. If the pause is merely seconds, then this will just
mean jerkiness and possible unexpected behaviour in gameplay. If the
pause is hours/days as with OS suspend, the game will appear to freeze
until it has caught up with real time.
- If calculating a fixed step takes longer than specified fixed step
period, the game will enter a death spiral where rendering each frame
takes longer and longer due to more and more fixed step updates being
run per frame and the game appears to freeze.
- There is no way to see current fixed step elapsed time inside fixed
steps. In order to track this, the game designer needs to add a custom
system inside `FixedUpdate` that calculates elapsed or step count in a
resource.
- Access to delta time inside fixed step is `FixedStep::period` rather
than `Time::delta`. This, coupled with the issue that `Time::elapsed`
isn't available at all for fixed steps, makes it that time requiring
systems are either implemented to be run in `FixedUpdate` or `Update`,
but rarely work in both.
- Fixes#8800
- Fixes#8543
- Fixes#7439
- Fixes#5692
## Solution
- Create a generic `Time<T>` clock that has no processing logic but
which can be instantiated for multiple usages. This is also exposed for
users to add custom clocks.
- Create three standard clocks, `Time<Real>`, `Time<Virtual>` and
`Time<Fixed>`, all of which contain their individual logic.
- Create one "default" clock, which is just `Time` (or `Time<()>`),
which will be overwritten from `Time<Virtual>` on each update, and
`Time<Fixed>` inside `FixedUpdate` schedule. This way systems that do
not care specifically which time they track can work both in `Update`
and `FixedUpdate` without changes and the behaviour is intuitive.
- Add `max_delta` to virtual time update, which limits how much can be
added to virtual time by a single update. This fixes both the behaviour
after a long freeze, and also the death spiral by limiting how many
fixed timestep iterations there can be per update. Possible future work
could be adding `max_accumulator` to add a sort of "leaky bucket" time
processing to possibly smooth out jumps in time while keeping frame rate
stable.
- Many minor tweaks and clarifications to the time functions and their
documentation.
## Changelog
- `Time::raw_delta()`, `Time::raw_elapsed()` and related methods are
moved to `Time<Real>::delta()` and `Time<Real>::elapsed()` and now match
`Time` API
- `FixedTime` is now `Time<Fixed>` and matches `Time` API.
- `Time<Fixed>` default timestep is now 64 Hz, or 15625 microseconds.
- `Time` inside `FixedUpdate` now reflects fixed timestep time, making
systems portable between `Update ` and `FixedUpdate`.
- `Time::pause()`, `Time::set_relative_speed()` and related methods must
now be called as `Time<Virtual>::pause()` etc.
- There is a new `max_delta` setting in `Time<Virtual>` that limits how
much the clock can jump by a single update. The default value is 0.25
seconds.
- Removed `on_fixed_timer()` condition as `on_timer()` does the right
thing inside `FixedUpdate` now.
## Migration Guide
- Change all `Res<Time>` instances that access `raw_delta()`,
`raw_elapsed()` and related methods to `Res<Time<Real>>` and `delta()`,
`elapsed()`, etc.
- Change access to `period` from `Res<FixedTime>` to `Res<Time<Fixed>>`
and use `delta()`.
- The default timestep has been changed from 60 Hz to 64 Hz. If you wish
to restore the old behaviour, use
`app.insert_resource(Time::<Fixed>::from_hz(60.0))`.
- Change `app.insert_resource(FixedTime::new(duration))` to
`app.insert_resource(Time::<Fixed>::from_duration(duration))`
- Change `app.insert_resource(FixedTime::new_from_secs(secs))` to
`app.insert_resource(Time::<Fixed>::from_seconds(secs))`
- Change `system.on_fixed_timer(duration)` to
`system.on_timer(duration)`. Timers in systems placed in `FixedUpdate`
schedule automatically use the fixed time clock.
- Change `ResMut<Time>` calls to `pause()`, `is_paused()`,
`set_relative_speed()` and related methods to `ResMut<Time<Virtual>>`
calls. The API is the same, with the exception that `relative_speed()`
will return the actual last ste relative speed, while
`effective_relative_speed()` returns 0.0 if the time is paused and
corresponds to the speed that was set when the update for the current
frame started.
## Todo
- [x] Update pull name and description
- [x] Top level documentation on usage
- [x] Fix examples
- [x] Decide on default `max_delta` value
- [x] Decide naming of the three clocks: is `Real`, `Virtual`, `Fixed`
good?
- [x] Decide if the three clock inner structures should be in prelude
- [x] Decide on best way to configure values at startup: is manually
inserting a new clock instance okay, or should there be config struct
separately?
- [x] Fix links in docs
- [x] Decide what should be public and what not
- [x] Decide how `wrap_period` should be handled when it is changed
- [x] ~~Add toggles to disable setting the clock as default?~~ No,
separate pull if needed.
- [x] Add tests
- [x] Reformat, ensure adheres to conventions etc.
- [x] Build documentation and see that it looks correct
## Contributors
Huge thanks to @alice-i-cecile and @maniwani while building this pull.
It was a shared effort!
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Cameron <51241057+maniwani@users.noreply.github.com>
Co-authored-by: Jerome Humbert <djeedai@gmail.com>
This adds support for **Multiple Asset Sources**. You can now register a
named `AssetSource`, which you can load assets from like you normally
would:
```rust
let shader: Handle<Shader> = asset_server.load("custom_source://path/to/shader.wgsl");
```
Notice that `AssetPath` now supports `some_source://` syntax. This can
now be accessed through the `asset_path.source()` accessor.
Asset source names _are not required_. If one is not specified, the
default asset source will be used:
```rust
let shader: Handle<Shader> = asset_server.load("path/to/shader.wgsl");
```
The behavior of the default asset source has not changed. Ex: the
`assets` folder is still the default.
As referenced in #9714
## Why?
**Multiple Asset Sources** enables a number of often-asked-for
scenarios:
* **Loading some assets from other locations on disk**: you could create
a `config` asset source that reads from the OS-default config folder
(not implemented in this PR)
* **Loading some assets from a remote server**: you could register a new
`remote` asset source that reads some assets from a remote http server
(not implemented in this PR)
* **Improved "Binary Embedded" Assets**: we can use this system for
"embedded-in-binary assets", which allows us to replace the old
`load_internal_asset!` approach, which couldn't support asset
processing, didn't support hot-reloading _well_, and didn't make
embedded assets accessible to the `AssetServer` (implemented in this pr)
## Adding New Asset Sources
An `AssetSource` is "just" a collection of `AssetReader`, `AssetWriter`,
and `AssetWatcher` entries. You can configure new asset sources like
this:
```rust
app.register_asset_source(
"other",
AssetSource::build()
.with_reader(|| Box::new(FileAssetReader::new("other")))
)
)
```
Note that `AssetSource` construction _must_ be repeatable, which is why
a closure is accepted.
`AssetSourceBuilder` supports `with_reader`, `with_writer`,
`with_watcher`, `with_processed_reader`, `with_processed_writer`, and
`with_processed_watcher`.
Note that the "asset source" system replaces the old "asset providers"
system.
## Processing Multiple Sources
The `AssetProcessor` now supports multiple asset sources! Processed
assets can refer to assets in other sources and everything "just works".
Each `AssetSource` defines an unprocessed and processed `AssetReader` /
`AssetWriter`.
Currently this is all or nothing for a given `AssetSource`. A given
source is either processed or it is not. Later we might want to add
support for "lazy asset processing", where an `AssetSource` (such as a
remote server) can be configured to only process assets that are
directly referenced by local assets (in order to save local disk space
and avoid doing extra work).
## A new `AssetSource`: `embedded`
One of the big features motivating **Multiple Asset Sources** was
improving our "embedded-in-binary" asset loading. To prove out the
**Multiple Asset Sources** implementation, I chose to build a new
`embedded` `AssetSource`, which replaces the old `load_interal_asset!`
system.
The old `load_internal_asset!` approach had a number of issues:
* The `AssetServer` was not aware of (or capable of loading) internal
assets.
* Because internal assets weren't visible to the `AssetServer`, they
could not be processed (or used by assets that are processed). This
would prevent things "preprocessing shaders that depend on built in Bevy
shaders", which is something we desperately need to start doing.
* Each "internal asset" needed a UUID to be defined in-code to reference
it. This was very manual and toilsome.
The new `embedded` `AssetSource` enables the following pattern:
```rust
// Called in `crates/bevy_pbr/src/render/mesh.rs`
embedded_asset!(app, "mesh.wgsl");
// later in the app
let shader: Handle<Shader> = asset_server.load("embedded://bevy_pbr/render/mesh.wgsl");
```
Notice that this always treats the crate name as the "root path", and it
trims out the `src` path for brevity. This is generally predictable, but
if you need to debug you can use the new `embedded_path!` macro to get a
`PathBuf` that matches the one used by `embedded_asset`.
You can also reference embedded assets in arbitrary assets, such as WGSL
shaders:
```rust
#import "embedded://bevy_pbr/render/mesh.wgsl"
```
This also makes `embedded` assets go through the "normal" asset
lifecycle. They are only loaded when they are actually used!
We are also discussing implicitly converting asset paths to/from shader
modules, so in the future (not in this PR) you might be able to load it
like this:
```rust
#import bevy_pbr::render::mesh::Vertex
```
Compare that to the old system!
```rust
pub const MESH_SHADER_HANDLE: Handle<Shader> = Handle::weak_from_u128(3252377289100772450);
load_internal_asset!(app, MESH_SHADER_HANDLE, "mesh.wgsl", Shader::from_wgsl);
// The mesh asset is the _only_ accessible via MESH_SHADER_HANDLE and _cannot_ be loaded via the AssetServer.
```
## Hot Reloading `embedded`
You can enable `embedded` hot reloading by enabling the
`embedded_watcher` cargo feature:
```
cargo run --features=embedded_watcher
```
## Improved Hot Reloading Workflow
First: the `filesystem_watcher` cargo feature has been renamed to
`file_watcher` for brevity (and to match the `FileAssetReader` naming
convention).
More importantly, hot asset reloading is no longer configured in-code by
default. If you enable any asset watcher feature (such as `file_watcher`
or `rust_source_watcher`), asset watching will be automatically enabled.
This removes the need to _also_ enable hot reloading in your app code.
That means you can replace this:
```rust
app.add_plugins(DefaultPlugins.set(AssetPlugin::default().watch_for_changes()))
```
with this:
```rust
app.add_plugins(DefaultPlugins)
```
If you want to hot reload assets in your app during development, just
run your app like this:
```
cargo run --features=file_watcher
```
This means you can use the same code for development and deployment! To
deploy an app, just don't include the watcher feature
```
cargo build --release
```
My intent is to move to this approach for pretty much all dev workflows.
In a future PR I would like to replace `AssetMode::ProcessedDev` with a
`runtime-processor` cargo feature. We could then group all common "dev"
cargo features under a single `dev` feature:
```sh
# this would enable file_watcher, embedded_watcher, runtime-processor, and more
cargo run --features=dev
```
## AssetMode
`AssetPlugin::Unprocessed`, `AssetPlugin::Processed`, and
`AssetPlugin::ProcessedDev` have been replaced with an `AssetMode` field
on `AssetPlugin`.
```rust
// before
app.add_plugins(DefaultPlugins.set(AssetPlugin::Processed { /* fields here */ })
// after
app.add_plugins(DefaultPlugins.set(AssetPlugin { mode: AssetMode::Processed, ..default() })
```
This aligns `AssetPlugin` with our other struct-like plugins. The old
"source" and "destination" `AssetProvider` fields in the enum variants
have been replaced by the "asset source" system. You no longer need to
configure the AssetPlugin to "point" to custom asset providers.
## AssetServerMode
To improve the implementation of **Multiple Asset Sources**,
`AssetServer` was made aware of whether or not it is using "processed"
or "unprocessed" assets. You can check that like this:
```rust
if asset_server.mode() == AssetServerMode::Processed {
/* do something */
}
```
Note that this refactor should also prepare the way for building "one to
many processed output files", as it makes the server aware of whether it
is loading from processed or unprocessed sources. Meaning we can store
and read processed and unprocessed assets differently!
## AssetPath can now refer to folders
The "file only" restriction has been removed from `AssetPath`. The
`AssetServer::load_folder` API now accepts an `AssetPath` instead of a
`Path`, meaning you can load folders from other asset sources!
## Improved AssetPath Parsing
AssetPath parsing was reworked to support sources, improve error
messages, and to enable parsing with a single pass over the string.
`AssetPath::new` was replaced by `AssetPath::parse` and
`AssetPath::try_parse`.
## AssetWatcher broken out from AssetReader
`AssetReader` is no longer responsible for constructing `AssetWatcher`.
This has been moved to `AssetSourceBuilder`.
## Duplicate Event Debouncing
Asset V2 already debounced duplicate filesystem events, but this was
_input_ events. Multiple input event types can produce the same _output_
`AssetSourceEvent`. Now that we have `embedded_watcher`, which does
expensive file io on events, it made sense to debounce output events
too, so I added that! This will also benefit the AssetProcessor by
preventing integrity checks for duplicate events (and helps keep the
noise down in trace logs).
## Next Steps
* **Port Built-in Shaders**: Currently the primary (and essentially
only) user of `load_interal_asset` in Bevy's source code is "built-in
shaders". I chose not to do that in this PR for a few reasons:
1. We need to add the ability to pass shader defs in to shaders via meta
files. Some shaders (such as MESH_VIEW_TYPES) need to pass shader def
values in that are defined in code.
2. We need to revisit the current shader module naming system. I think
we _probably_ want to imply modules from source structure (at least by
default). Ideally in a way that can losslessly convert asset paths
to/from shader modules (to enable the asset system to resolve modules
using the asset server).
3. I want to keep this change set minimal / get this merged first.
* **Deprecate `load_internal_asset`**: we can't do that until we do (1)
and (2)
* **Relative Asset Paths**: This PR significantly increases the need for
relative asset paths (which was already pretty high). Currently when
loading dependencies, it is assumed to be an absolute path, which means
if in an `AssetLoader` you call `context.load("some/path/image.png")` it
will assume that is the "default" asset source, _even if the current
asset is in a different asset source_. This will cause breakage for
AssetLoaders that are not designed to add the current source to whatever
paths are being used. AssetLoaders should generally not need to be aware
of the name of their current asset source, or need to think about the
"current asset source" generally. We should build apis that support
relative asset paths and then encourage using relative paths as much as
possible (both via api design and docs). Relative paths are also
important because they will allow developers to move folders around
(even across providers) without reprocessing, provided there is no path
breakage.
# Objective
- Add a [Deferred
Renderer](https://en.wikipedia.org/wiki/Deferred_shading) to Bevy.
- This allows subsequent passes to access per pixel material information
before/during shading.
- Accessing this per pixel material information is needed for some
features, like GI. It also makes other features (ex. Decals) simpler to
implement and/or improves their capability. There are multiple
approaches to accomplishing this. The deferred shading approach works
well given the limitations of WebGPU and WebGL2.
Motivation: [I'm working on a GI solution for
Bevy](https://youtu.be/eH1AkL-mwhI)
# Solution
- The deferred renderer is implemented with a prepass and a deferred
lighting pass.
- The prepass renders opaque objects into the Gbuffer attachment
(`Rgba32Uint`). The PBR shader generates a `PbrInput` in mostly the same
way as the forward implementation and then [packs it into the
Gbuffer](ec1465559f/crates/bevy_pbr/src/render/pbr.wgsl (L168)).
- The deferred lighting pass unpacks the `PbrInput` and [feeds it into
the pbr()
function](ec1465559f/crates/bevy_pbr/src/deferred/deferred_lighting.wgsl (L65)),
then outputs the shaded color data.
- There is now a resource
[DefaultOpaqueRendererMethod](ec1465559f/crates/bevy_pbr/src/material.rs (L599))
that can be used to set the default render method for opaque materials.
If materials return `None` from
[opaque_render_method()](ec1465559f/crates/bevy_pbr/src/material.rs (L131))
the `DefaultOpaqueRendererMethod` will be used. Otherwise, custom
materials can also explicitly choose to only support Deferred or Forward
by returning the respective
[OpaqueRendererMethod](ec1465559f/crates/bevy_pbr/src/material.rs (L603))
- Deferred materials can be used seamlessly along with both opaque and
transparent forward rendered materials in the same scene. The [deferred
rendering
example](https://github.com/DGriffin91/bevy/blob/deferred/examples/3d/deferred_rendering.rs)
does this.
- The deferred renderer does not support MSAA. If any deferred materials
are used, MSAA must be disabled. Both TAA and FXAA are supported.
- Deferred rendering supports WebGL2/WebGPU.
## Custom deferred materials
- Custom materials can support both deferred and forward at the same
time. The
[StandardMaterial](ec1465559f/crates/bevy_pbr/src/render/pbr.wgsl (L166))
does this. So does [this
example](https://github.com/DGriffin91/bevy_glowy_orb_tutorial/blob/deferred/assets/shaders/glowy.wgsl#L56).
- Custom deferred materials that require PBR lighting can create a
`PbrInput`, write it to the deferred GBuffer and let it be rendered by
the `PBRDeferredLightingPlugin`.
- Custom deferred materials that require custom lighting have two
options:
1. Use the base_color channel of the `PbrInput` combined with the
`STANDARD_MATERIAL_FLAGS_UNLIT_BIT` flag.
[Example.](https://github.com/DGriffin91/bevy_glowy_orb_tutorial/blob/deferred/assets/shaders/glowy.wgsl#L56)
(If the unlit bit is set, the base_color is stored as RGB9E5 for extra
precision)
2. A Custom Deferred Lighting pass can be created, either overriding the
default, or running in addition. The a depth buffer is used to limit
rendering to only the required fragments for each deferred lighting
pass. Materials can set their respective depth id via the
[deferred_lighting_pass_id](b79182d2a3/crates/bevy_pbr/src/prepass/prepass_io.wgsl (L95))
attachment. The custom deferred lighting pass plugin can then set [its
corresponding
depth](ec1465559f/crates/bevy_pbr/src/deferred/deferred_lighting.wgsl (L37)).
Then with the lighting pass using
[CompareFunction::Equal](ec1465559f/crates/bevy_pbr/src/deferred/mod.rs (L335)),
only the fragments with a depth that equal the corresponding depth
written in the material will be rendered.
Custom deferred lighting plugins can also be created to render the
StandardMaterial. The default deferred lighting plugin can be bypassed
with `DefaultPlugins.set(PBRDeferredLightingPlugin { bypass: true })`
---------
Co-authored-by: nickrart <nickolas.g.russell@gmail.com>
