# Objective
- Using multiple raster passes to generate the depth pyramid is
extremely slow
- Pulling data from the source image is the largest bottleneck, it's
important to sample in a cache-aware pattern
- Barriers and pipeline drain between the raster passes is the second
largest bottleneck
- Each separate RenderPass on the CPU is _really_ expensive
## Solution
- Port [FidelityFX SPD](https://gpuopen.com/fidelityfx-spd) to WGSL,
replacing meshlet's existing multiple raster passes with a ~~single~~
two compute dispatches. Lack of coherent buffers means we have to do the
the last 64x64 tile from mip 7+ in a separate dispatch to ensure the mip
6 writes were flushed :(
- Workgroup shared memory version only at the moment, as the subgroup
operation is blocked by our upgrade to wgpu 0.20 #13186
- Don't enforce a power-of-2 depth pyramid texture size, simply scaling
by 0.5 is fine
# Objective
- Add motion vector support to the skybox
- This fixes the last remaining "gap" to complete the motion blur
feature
## Solution
- Add a pipeline for the skybox to write motion vectors to the prepass
## Testing
- Used examples to test motion vectors using motion blur
https://github.com/bevyengine/bevy/assets/2632925/74c0778a-7e77-4e68-8111-05791e4bfdd2
---------
Co-authored-by: Patrick Walton <pcwalton@mimiga.net>
# Objective
- Adopted from #13528.
- `rodio` released 0.18! While we are working on migrating away from it
and towards `kira`, it is still good to keep our dependencies
up-to-date.
## Solution
- Update `Cargo.toml` to depend on `rodio` 0.18.
- #13528 was failing because it didn't update `rodio` for
`wasm32-unknown-unknown` too.
## Testing
- The CI should catch any errors here, but you can also run an audio
example if you want like `spatial_audio_2d`.
---
## Changelog
- Updated `rodio` to 0.18.
---------
Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
# Objective
Prerequisite to #13579.
Combine separate `Substates` transition systems to centralize transition
logic and exert more control over it.
## Solution
Originally the transition happened in 2 stages:
- `apply_state_transition` in `ManualTransitions` handled `NextState`,
- closure system in `DependentTransitions` handled parent-related
changes, insertion and deletion of the substate.
Now:
- Both transitions are processed in a single closure system during
`DependentTransitions`.
- Since `Substates` no longer use `ManualTransitions`, it's been renamed
to `RootTransitions`. Only root states use it.
- When `Substates` state comes into existence, it will try to initialize
from `NextState` and fallback to `should_exist` result.
- Remove `apply_state_transition` from public API.
Consequentially, removed the possibility of multiple
`StateTransitionEvent`s when both transition systems fire in a single
frame.
## Changelog
- Renamed `ManualTransitions` to `RootTransitions`.
- `Substates` will initialize their value with `NextState` if available
and fallback to `should_exist` result.
## Migration Guide
- `apply_state_transition` is no longer publicly available, run the
`StateTransition` schedule instead.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
- The current version of the `meshopt` dependency is incorrect, as
`bevy_pbr` uses features introduced in `meshopt` `0.2.1`
- This causes errors like this when only `meshopt` `0.2` is present in
`Cargo.lock`:
```
error[E0432]: unresolved imports
`meshopt::ffi::meshopt_optimizeMeshlet`, `meshopt::simplify_scale`
--> crates\bevy_pbr\src\meshlet\from_mesh.rs:10:27
|
10 | ffi::{meshopt_Bounds, meshopt_optimizeMeshlet},
| ^^^^^^^^^^^^^^^^^^^^^^^
| no `meshopt_optimizeMeshlet` in `ffi`
| help: a similar name exists in the module: `meshopt_optimizeOverdraw`
11 | simplify, simplify_scale, Meshlets, SimplifyOptions,
VertexDataAdapter,
| ^^^^^^^^^^^^^^ no `simplify_scale` in the root
```
## Solution
- Specify the actual minimum version of `meshopt` that `bevy_pbr`
requires
# Objective
Prerequisite to #13579.
Make state transition schedule running simpler.
## Solution
- Remove `should_run_transition` which read the latest event and
fake-fire an event for the startup transitions (e.g. startup
`OnEnter()`).
- Account for startup event, by actually emitting an event when adding
states to `App`.
- Replace `should_run_transition` with `last_transition`, which is a
light wrapper over `EventReader::read().last()`.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Fixes#13606.
Also Fixes#13614.
## Solution
Added the missing trait impls, and made `gizmos.arc_2d()` work with a
counter-clockwise angle.
## Testing
- Updated the render_primitives example, and it works.
# Objective
- Followup to #13548
- It added a list of all possible labels to documentation. This seems
hard to keep up and doesn't stop people from making spelling mistake
## Solution
- Add an enum that can create all the labels possible, and encourage its
use rather than manually typed labels
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Rob Parrett <robparrett@gmail.com>
# Objective
- Fixes#13500
- Images that are `RenderAssetUsages::RENDER_WORLD` don't free their
memory when they are no longer used
## Solution
- Remove their bind group when the handles are unused
This is a revamped equivalent to #9902, though it shares none of the
code. It handles all special cases that I've tested correctly.
The overall technique consists of double-buffering the joint matrix and
morph weights buffers, as most of the previous attempts to solve this
problem did. The process is generally straightforward. Note that, to
avoid regressing the ability of mesh extraction, skin extraction, and
morph target extraction to run in parallel, I had to add a new system to
rendering, `set_mesh_motion_vector_flags`. The comment there explains
the details; it generally runs very quickly.
I've tested this with modified versions of the `animated_fox`,
`morph_targets`, and `many_foxes` examples that add TAA, and the patch
works. To avoid bloating those examples, I didn't add switches for TAA
to them.
Addresses points (1) and (2) of #8423.
## Changelog
### Fixed
* Motion vectors, and therefore TAA, are now supported for meshes with
skins and/or morph targets.
# Objective
Adds capability to clear all components on an entity without de-spawning
said entity.
## Testing
The function calls `remove_by_id` on every component in the entity
archetype - wasn't sure if it's worth going out of our way to create a
test for this considering `remove_by_id` is already unit tested.
---
## Changelog
Added `clear` function to `EntityWorldMut` which removes all components
on an entity.
## Migration Guide
N/A
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
- The default font size is too small to be useful in examples or for
debug text.
- Fixes#13587
## Solution
- Updated the default font size value in `TextStyle` from 12px to 24px.
- Resorted to Text defaults in examples to use the default font size in
most of them.
## Testing
- WIP
---
## Migration Guide
- The default font size has been increased to 24px from 12px. Make sure
you set the font to the appropriate values in places you were using
`Default` text style.
# Objective
Part of https://github.com/bevyengine/bevy/issues/13529
Helps https://github.com/bevyengine/bevy/pull/13533
Splitting up `bevy_transform` makes it easier to selectively include or
exclude parts of it in such a way that it's possible to include only a
small part with a small dependency tree.
## Solution
Make the crate more modular.
---------
Signed-off-by: Torstein Grindvik <torstein.grindvik@muybridge.com>
Co-authored-by: Torstein Grindvik <torstein.grindvik@muybridge.com>
# Objective
Unifies the naming convention between `StateTransitionEvent<S>` and
transition schedules.
## Migration Guide
- `StateTransitionEvent<S>` and `OnTransition<S>` schedule had their
fields renamed to `exited` and `entered` to match schedules.
# Objective
- In #13542 I broke example `color_grading`: the UI is not updated to
reflect changed camera settings
- Fixes#13590.
## Solution
- Update the UI when changing color grading
# Objective
- Allow using image assets that don't have an extensions and whose
format is unknown. This is useful for loading images from arbitrary HTTP
URLs.
## Solution
- This PR adds a new variant to `ImageFormatSetting` called `Guess`. The
loader will use `image::guess_format` to deduce the format based on the
content of the file.
## Testing
- I locally removed the extension of bevy_bird_dark, and ran a modified
version of the `sprite` example:
```rust
//! Displays a single [`Sprite`], created from an image.
use bevy::{
prelude::*,
render::texture::{ImageFormatSetting, ImageLoaderSettings},
};
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_systems(Startup, setup)
.run();
}
fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
commands.spawn(Camera2dBundle::default());
commands.spawn(SpriteBundle {
texture: asset_server
.load_with_settings("branding/bevy_bird_dark", |s: &mut ImageLoaderSettings| {
s.format = ImageFormatSetting::Guess
}),
..default()
});
}
```
## Changelog
### Added
`ImageFormatSetting::Guess` to automatically guess the format of an
image asset from its content.
Co-authored-by: François Mockers <mockersf@gmail.com>
## Objective
Use the "standard" text size / placement for the new text in these
examples.
Continuation of an effort started here:
https://github.com/bevyengine/bevy/pull/8478
This is definitely not comprehensive. I did the ones that were easy to
find and relatively straightforward updates. I meant to just do
`3d_shapes` and `2d_shapes`, but one thing lead to another.
## Solution
Use `font_size: 20.0`, the default (built-in) font, `Color::WHITE`
(default), and `Val::Px(12.)` from the edges of the screen.
There are a few little drive-by cleanups of defaults not being used,
etc.
## Testing
Ran the changed examples, verified that they still look reasonable.
# Objective
- Fixes https://github.com/bevyengine/bevy/issues/13155
- fixes https://github.com/bevyengine/bevy/issues/13517
- Supercedes https://github.com/bevyengine/bevy/pull/13381
- Requires https://github.com/DioxusLabs/taffy/pull/661
## Solution
- Taffy has been updated to:
- Apply size styles to absolutely positioned children
- Pass the node's `Style` through to the measure function
- Bevy's image measure function has been updated to make use of this
style information
## Notes
- This is currently using a git version of Taffy. If this is tested as
fixing the issue then we can turn that into a Taffy 0.5 release (this
would be the only change between Taffy 0.4 and Taffy 0.5 so upgrading is
not expected to be an issue)
- This implementation may not be completely correct. I would have
preferred to extend Taffy's gentest infrastructure to handle images and
used that to nail down the correct behaviour. But I don't have time for
that atm so we'll have to iterate on this in future. This PR at least
puts that under Bevy's control.
## Testing
- I manually tested the game_menu_example (from
https://github.com/bevyengine/bevy/issues/13155)
- More testing is probably merited
---
## Changelog
No changelog should be required as it fixes a regression on `main` that
was not present in bevy 0.13. The changelog for "Taffy upgrade" may want
to be changed from 0.4 to 0.5 if this change gets merged.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: François Mockers <francois.mockers@vleue.com>
# Objective
In #13343, `WorldQuery::get_state` was constrained from `&World` as the
argument to `&Components`, but `WorldQuery::init_state` hasn't yet been
changed from `&mut World` to match.
Fixes#13358
## Solution
Create a wrapper around `&mut Components` and `&mut Storages` that can
be obtained from `&mut World` with a `component_initializer` method.
This new `ComponentInitializer` re-exposes the API on `&mut Components`
minus the `&mut Storages` parameter where it was present. For the
`&Components` API, it simply derefs to its `components` field.
## Changelog
### Added
The `World::component_initializer` method.
The `ComponentInitializer` struct that re-exposes `Components` API.
### Changed
`WorldQuery::init_state` now takes `&mut ComponentInitializer` instead
of `&mut World`.
## Migration Guide
Instead of passing `&mut World` to `WorldQuery::init_state` directly,
pass in a mutable reference to the struct returned from
`World::component_initializer`.
# Objective
- Fixes#13038
## Solution
- Disable gpu preprocessing when feature
`SAMPLED_TEXTURE_AND_STORAGE_BUFFER_ARRAY_NON_UNIFORM_INDEXING` is not
available
## Testing
- Tested on android device that used to crash
# Objective
- Motion blur does not currently work with skyboxes or anything else
that does not write to depth.
## Solution
- When computing blur, include fragments with no depth, as long as they
are onscreen.
## Testing
- Tested with the examples - the motion_blur example uncovered a bug
with this fix, where offscreen pixels where now being sampled and
causing artifacts.
- Attached example showing the skybox being sampled in the blur (note
the feathering on edges):
https://github.com/bevyengine/bevy/assets/2632925/fc14b0c1-2394-46a5-a2b9-a859efcd23ef
# Objective
- since #13523, UI is broken in WebGPU
```
Compilation log for [Invalid ShaderModule (unlabeled)]:
1 error(s) generated while compiling the shader:
:108:27 error: 'textureSample' must only be called from uniform control flow
let texture_color_1 = textureSample(sprite_texture, sprite_sampler, in_2.uv);
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
:151:19 note: called by 'draw_background' from 'fragment'
let _e5 = draw_background(in);
^^^^^^^^^^^^^^^^^^^
:147:5 note: control flow depends on possibly non-uniform value
if _e3 {
^^
:146:23 note: parameter 'in' of 'fragment' may be non-uniform
let _e3 = enabled(in.flags, BORDER);
```
## Solution
- call `textureSample` from outside the if. both branches are using the
same parameters
# Objective
- In particularly dark scenes, auto-exposure would lead to an unexpected
darkening of the view.
- Fixes#13446.
## Solution
The average luminance should default to something else than 0.0 instead,
when there are no samples. We set it to `settings.min_log_lum`.
## Testing
I was able to reproduce the problem on the `auto_exposure` example by
setting the point light intensity to 2000 and looking into the
right-hand corner. There was a sudden darkening.
Now, the discontinuity is gone.
---------
Co-authored-by: Alice Cecile <alice.i.cecil@gmail.com>
Co-authored-by: Bram Buurlage <brambuurlage@gmail.com>
# Objective
- The Gltf loader has a ton of features to load parts of an asset that
are essentially undocumented.
## Solution
- Add some docs to explain some of those features
- The docs is definitely inspired by the bevy cheatbook page on the
subject but it goes in a lot less details
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: François Mockers <francois.mockers@vleue.com>
Currently, either an `EntityRef` or `EntityMut` is required in order to
reflect a component on an entity. This can, however, be generalized to
`FilteredEntityRef` and `FilteredEntityMut`, which are versions of
`EntityRef` and `EntityMut` that restrict the components that can be
accessed. This is useful because dynamic queries yield
`FilteredEntityRef` and `FilteredEntityMut` rows when iterated over.
This commit changes `ReflectComponent::contains()`,
`ReflectComponent::reflect()`, and `ReflectComponent::reflect_mut()` to
take an `Into<FilteredEntityRef>` (in the case of `contains()` and
`reflect()`) and `Into<FilteredEntityMut>` (in the case of
`reflect_mut()`). Fortunately, `EntityRef` and `EntityMut` already
implement the corresponding trait, so nothing else has to be done to the
public API. Note that in order to implement
`ReflectComponent::reflect_mut()` properly, an additional method
`FilteredEntityMut::into_mut()` was required, to match the one on
`EntityMut`.
I ran into this when attempting to implement `QUERY` in the Bevy Remote
Protocol when trying to iterate over rows of dynamic queries and fetch
the associated components without unsafe code. There were other
potential ways to work around this problem, but they required either
reimplementing the query logic myself instead of using regular Bevy
queries or storing entity IDs and then issuing another query to fetch
the associated `EntityRef`. Both of these seemed worse than just
improving the `reflect()` function.
## Migration Guide
* `ReflectComponent::contains`, `ReflectComponent::reflect`, and
`ReflectComponent::reflect_mut` now take `FilteredEntityRef` (in the
case of `contains()` and `reflect()`) and `FilteredEntityMut` (in the
case of `reflect_mut()`) parameters. `FilteredEntityRef` and
`FilteredEntityMut` have very similar APIs to `EntityRef` and
`EntityMut` respectively, but optionally restrict the components that
can be accessed.
# Objective
- `FilteredEntity{Ref,Mut}` various `get` methods never checked that the
given component was present on the entity, only the access allowed
reading/writing them, which is always the case when it is constructed
from a `EntityRef`/`EntityMut`/`EntityWorldMut` (and I guess can also
happen with queries containing `Option<T>` that get transmuted).
- In those cases the various `get` methods were calling
`debug_checked_unwrap` on `None`s, which is UB when debug assertions are
not enabled;
- The goal is thus to fix this soundness issue.
## Solution
- Don't call `debug_checked_unwrap` on those `None` and instead
`flatten` them.
## Testing
- This PR includes regression tests for each combination of
`FilteredEntityRef`/`FilteredEntityMut` and component
present/not-present. The two tests for the not-present cases fail on
`main` but success with this PR changes.
# Objective
- Prevent the case where a hook/observer is triggered but the source
entity/component no longer exists
## Solution
- Re-order command application such that all hooks/observers that are
notified will run before any have a chance to invalidate the result.
## Testing
Updated relevant tests in `bevy_ecs`, all other tests pass.
---------
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
Co-authored-by: Mike Hsu <mike.hsu@gmail.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Fixes#13118
If you use `Sprite` or `Mesh2d` and create `Camera` with
* hdr=false
* any tonemapper
You would get
```
wgpu error: Validation Error
Caused by:
In Device::create_render_pipeline
note: label = `sprite_pipeline`
Error matching ShaderStages(FRAGMENT) shader requirements against the pipeline
Shader global ResourceBinding { group: 0, binding: 19 } is not available in the pipeline layout
Binding is missing from the pipeline layout
```
Because of missing tonemapping LUT bindings
## Solution
Add missing bindings for tonemapping LUT's to `SpritePipeline` &
`Mesh2dPipeline`
## Testing
I checked that
* `tonemapping`
* `color_grading`
* `sprite_animations`
* `2d_shapes`
* `meshlet`
* `deferred_rendering`
examples are still working
2d cases I checked with this code:
```
use bevy::{
color::palettes::css::PURPLE, core_pipeline::tonemapping::Tonemapping, prelude::*,
sprite::MaterialMesh2dBundle,
};
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_systems(Startup, setup)
.add_systems(Update, toggle_tonemapping_method)
.run();
}
fn setup(
mut commands: Commands,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<ColorMaterial>>,
asset_server: Res<AssetServer>,
) {
commands.spawn(Camera2dBundle {
camera: Camera {
hdr: false,
..default()
},
tonemapping: Tonemapping::BlenderFilmic,
..default()
});
commands.spawn(MaterialMesh2dBundle {
mesh: meshes.add(Rectangle::default()).into(),
transform: Transform::default().with_scale(Vec3::splat(128.)),
material: materials.add(Color::from(PURPLE)),
..default()
});
commands.spawn(SpriteBundle {
texture: asset_server.load("asd.png"),
..default()
});
}
fn toggle_tonemapping_method(
keys: Res<ButtonInput<KeyCode>>,
mut tonemapping: Query<&mut Tonemapping>,
) {
let mut method = tonemapping.single_mut();
if keys.just_pressed(KeyCode::Digit1) {
*method = Tonemapping::None;
} else if keys.just_pressed(KeyCode::Digit2) {
*method = Tonemapping::Reinhard;
} else if keys.just_pressed(KeyCode::Digit3) {
*method = Tonemapping::ReinhardLuminance;
} else if keys.just_pressed(KeyCode::Digit4) {
*method = Tonemapping::AcesFitted;
} else if keys.just_pressed(KeyCode::Digit5) {
*method = Tonemapping::AgX;
} else if keys.just_pressed(KeyCode::Digit6) {
*method = Tonemapping::SomewhatBoringDisplayTransform;
} else if keys.just_pressed(KeyCode::Digit7) {
*method = Tonemapping::TonyMcMapface;
} else if keys.just_pressed(KeyCode::Digit8) {
*method = Tonemapping::BlenderFilmic;
}
}
```
---
## Changelog
Fix the bug which led to the crash when user uses any tonemapper without
hdr for rendering sprites and 2d meshes.
# Objective
- Fixes#13521
## Solution
Set `ambient_intensity` to 0.0 in volumetric_fog example.
I chose setting it explicitly over changing the default in order to make
it clear that this needs to be set depending on whether you have an
`EnvironmentMapLight`. See documentation for `ambient_intensity` and
related members.
## Testing
- Run the volumetric_fog example and notice how the light shown in
#13521 is not there anymore, as expected.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
- Small improvements on the `color_grading` example
## Solution
- Simplify button creation by creating them in the default state, the
selected one is automatically selected
- Don't update the UI if not needed
- Also invert the border of the selected button
- Simplify text update
# Objective
- #13418 broke volumetric fog
```
wgpu error: Validation Error
Caused by:
In a RenderPass
note: encoder = `<CommandBuffer-(2, 4, Metal)>`
In a set_bind_group command
note: bind group = `mesh_view_bind_group`
Bind group 0 expects 5 dynamic offsets. However 4 dynamic offsets were provided.
```
## Solution
- add ssr offset to volumetric fog bind group
# Objective
Fix#13530 (just realized creating an issue was unnecessary since it's a
super simple fix)
## Solution
Add a cfg feature attribute
## Testing
Compiles fine now
# Objective
Fixes#13535.
## Solution
I implemented `Reflect` for close to all math types now, except for some
types that it would cause issues (like some boxed types).
## Testing
- Everything seems to still build, will await CI though.
---
## Changelog
- Made close to all math types implement `Reflect`.
# Objective
- Fixes#13503
- Fix other various bugs I noticed while debugging above issue.
## Solution
- Change the antialiasing(AA) method. It was using fwidth which is the
derivative between pixels, but there were a lot of artifacts being added
from this. So just use the sdf value. This aa method probably isn't as
smooth looking, but better than having artifacts. Below is a
visualization of the fwidth.
- Use the internal sdf for drawing the background instead of the
external sdf and extract the border for these type of nodes. This fixed
2 bugs, one with the background coloring the AA pixels on the edge of
rounded borders. And also allows for the border to use a transparent
color.
- Don't extract borders if all the widths are zero.
## Testing
- played a bunch with the example in the linked issue.
This PR:
Main:
- ran the `borders` and `rounded_borders` examples
---
## Changelog
- Fixed various antialiasing issues to do with rounded ui borders.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Andreas Weibye <13300393+Weibye@users.noreply.github.com>
# Objective
- Show + Visually Test that 3D primitive sampling works
- Make an example that looks nice.
## Solution
- Added a `sampling_primitives` examples which shows all the 3D
primitives being sampled, with a firefly aesthetic.
## Testing
- `cargo run --example sampling_primitives`
- Haven't tested WASM.
## Changelog
### Added
- Added a new example, `sampling_primitives`, to showcase all the 3D
sampleable primitives.
## Additional notes:
This example borrowed a bunch of code from the other sampling example,
by @mweatherley.
In future updates this example should be updated with new 3D primitives
as they become sampleable.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Joona Aalto <jondolf.dev@gmail.com>
# Objective
Fixes#13456
## Solution
Moved `bevy_math`'s `Reflect` impls from `bevy_reflect` to `bevy_math`.
### Quick note
I accidentally used the same commit message while resolving a merge
conflict (first time I had to resolve a conflict). Sorry about that.
# Objective
Fixes#13427.
## Solution
I changed the traits, and updated all usages.
## Testing
The `render_primitives` example still works perfectly.
---
## Changelog
- Made `gizmos.primitive_2d()` and `gizmos.primitive_3d()` take the
primitives by ref.
## Migration Guide
- Any usages of `gizmos.primitive_2d()` and/or `gizmos.primitive_3d()`
need to be updated to pass the primitive in by reference.
# Objective
We introduced a bunch of neat random sampling stuff in this release; we
should do a good job of showing people how to use it, and writing
examples is part of this.
## Solution
A new Math example, `random_sampling`, shows off the `ShapeSample` API
functionality. For the moment, it renders a cube and allows the user to
sample points from its interior or boundary in sets of either 1 or 100:
<img width="1440" alt="Screenshot 2024-05-25 at 1 16 08 PM"
src="https://github.com/bevyengine/bevy/assets/2975848/9cb6f53f-c89a-42c2-8907-b11d294c402a">
On the level of code, these are reflected by two ways of using
`ShapeSample`:
```rust
// Get a single random Vec3:
let sample: Vec3 = match *mode {
Mode::Interior => shape.0.sample_interior(rng),
Mode::Boundary => shape.0.sample_boundary(rng),
};
```
```rust
// Get 100 random Vec3s:
let samples: Vec<Vec3> = match *mode {
Mode::Interior => {
let dist = shape.0.interior_dist();
dist.sample_iter(&mut rng).take(100).collect()
}
Mode::Boundary => {
let dist = shape.0.boundary_dist();
dist.sample_iter(&mut rng).take(100).collect()
}
};
```
## Testing
Run the example!
## Discussion
Maybe in the future it would be nice to show off all of the different
shapes that we have implemented `ShapeSample` for, but I wanted to start
just by demonstrating the functionality. Here, I chose a cube because
it's simple and because it looks good rendered transparently with
backface culling disabled.
