# Objective
The quality of Bevy's text rendering can vary wildly depending on the
font, font size, pixel alignment and scale factor.
But this situation can be improved dramatically with some small
adjustments.
## Solution
* Text node positions are rounded to the nearest physical pixel before
rendering.
* Each glyph texture has a 1-pixel wide transparent border added along
its edges.
This means font atlases will use more memory because of the extra pixel
of padding for each glyph but it's more than worth it I think (although
glyph size is increased by 2 pixels on both axes, the net increase is 1
pixel as the font texture atlas's padding has been removed).
## Results
Screenshots are from the 'ui' example with a scale factor of 1.5.
Things can get much uglier with the right font and worst scale
factor<sup>tm</sup>.
### before
<img width="300" alt="list-bad-text"
src="https://github.com/bevyengine/bevy/assets/27962798/482b384d-8743-4bae-9a65-468ff1b4c301">
### after
<img width="300" alt="good_list_text"
src="https://github.com/bevyengine/bevy/assets/27962798/34323b0a-f714-47ba-9728-a59804987bc8">
---
## Changelog
* Font texture atlases are no longer padded.
* Each glyph texture has a 1-pixel wide padding added along its edges.
* Text node positions are rounded to the nearest physical pixel before
rendering.
# Objective
Fixes#10436
Alternative to #10465
## Solution
`load_untyped_async` / `load_internal` currently has a bug. In
`load_untyped_async`, we pass None into `load_internal` for the
`UntypedHandle` of the labeled asset path. This results in a call to
`get_or_create_path_handle_untyped` with `loader.asset_type_id()`
This is a new code path that wasn't hit prior to the newly added
`load_untyped` because `load_untyped_async` was a private method only
used in the context of the `load_folder` impl (which doesn't have
labels)
The fix required some refactoring to catch that case and defer handle
retrieval. I have also made `load_untyped_async` public as it is now
"ready for public use" and unlocks new scenarios.
# Objective
Currently, if a large amount of inactive cameras are spawned, they will
immensely slow down performance.
This can be reproduced by adding
```rust
let default_image = images.add(default());
for _ in 0..10000 {
commands.spawn(Camera3dBundle {
camera: Camera {
is_active: false,
target: RenderTarget::Image(default_image.clone()),
..default()
},
..default()
});
}
```
to for example `3d_shapes`.
Using `tracy`, it's clear that preparing view bind groups for all
cameras is still happening.
Also, visibility checks on the extracted views from inactive cameras
also take place.
## Performance gains
The following `tracy` comparisons show the effect of skipping this
unneeded work.
Yellow is Bevy main, red is with the fix.
### Visibility checks
![bevy-visibility-check-savings](https://github.com/bevyengine/bevy/assets/52322338/154a20ce-bd70-487e-a85c-8b993950ea2b)
### Bind group preparation
![bevy-mesh2d-savings](https://github.com/bevyengine/bevy/assets/52322338/a48d8d9a-8c37-4c34-9698-b1b1bf01f070)
## Solution
- Check if the cameras are inactive in the appropriate places, and if so
skip them
## Changelog
### Changed
- Do not extract views from inactive cameras or check visiblity from
their extracted views
Signed-off-by: Torstein Grindvik <torstein.grindvik@muybridge.com>
Co-authored-by: Torstein Grindvik <torstein.grindvik@muybridge.com>
(This is my first PR here, so I've probably missed some things. Please
let me know what else I should do to help you as a reviewer!)
# Objective
Due to https://github.com/rust-lang/rust/issues/117800, the `derive`'d
`PartialEq::eq` on `Entity` isn't as good as it could be. Since that's
used in hashtable lookup, let's improve it.
## Solution
The derived `PartialEq::eq` short-circuits if the generation doesn't
match. However, having a branch there is sub-optimal, especially on
64-bit systems like x64 that could just load the whole `Entity` in one
load anyway.
Due to complications around `poison` in LLVM and the exact details of
what unsafe code is allowed to do with reference in Rust
(https://github.com/rust-lang/unsafe-code-guidelines/issues/346), LLVM
isn't allowed to completely remove the short-circuiting. `&Entity` is
marked `dereferencable(8)` so LLVM knows it's allowed to *load* all 8
bytes -- and does so -- but it has to assume that the `index` might be
undef/poison if the `generation` doesn't match, and thus while it finds
a way to do it without needing a branch, it has to do something slightly
more complicated than optimal to combine the results. (LLVM is allowed
to change non-short-circuiting code to use branches, but not the other
way around.)
Here's a link showing the codegen today:
<https://rust.godbolt.org/z/9WzjxrY7c>
```rust
#[no_mangle]
pub fn demo_eq_ref(a: &Entity, b: &Entity) -> bool {
a == b
}
```
ends up generating the following assembly:
```asm
demo_eq_ref:
movq xmm0, qword ptr [rdi]
movq xmm1, qword ptr [rsi]
pcmpeqd xmm1, xmm0
pshufd xmm0, xmm1, 80
movmskpd eax, xmm0
cmp eax, 3
sete al
ret
```
(It's usually not this bad in real uses after inlining and LTO, but it
makes a strong demo.)
This PR manually implements `PartialEq::eq` *without* short-circuiting,
and because that tells LLVM that neither the generations nor the index
can be poison, it doesn't need to be so careful and can generate the
"just compare the two 64-bit values" code you'd have probably already
expected:
```asm
demo_eq_ref:
mov rax, qword ptr [rsi]
cmp qword ptr [rdi], rax
sete al
ret
```
Since this doesn't change the representation of `Entity`, if it's
instead passed by *value*, then each `Entity` is two `u32` registers,
and the old and the new code do exactly the same thing. (Other
approaches, like changing `Entity` to be `[u32; 2]` or `u64`, affect
this case.)
This should hopefully merge easily with changes like
https://github.com/bevyengine/bevy/pull/9907 that also want to change
`Entity`.
## Benchmarks
I'm not super-confident that I got my machine fully consistent for
benchmarking, but whether I run the old or the new one first I get
reasonably consistent results.
Here's a fairly typical example of the benchmarks I added in this PR:
![image](https://github.com/bevyengine/bevy/assets/18526288/24226308-4616-4082-b0ff-88fc06285ef1)
Building the sets seems to be basically the same. It's usually reported
as noise, but sometimes I see a few percent slower or faster.
But lookup hits in particular -- since a hit checks that the key is
equal -- consistently shows around 10% improvement.
`cargo run --example many_cubes --features bevy/trace_tracy --release --
--benchmark` showed as slightly faster with this change, though if I had
to bet I'd probably say it's more noise than meaningful (but at least
it's not worse either):
![image](https://github.com/bevyengine/bevy/assets/18526288/58bb8c96-9c45-487f-a5ab-544bbfe9fba0)
This is my first PR here -- and my first time running Tracy -- so please
let me know what else I should run, or run things on your own more
reliable machines to double-check.
---
## Changelog
(probably not worth including)
Changed: micro-optimized `Entity::eq` to help LLVM slightly.
## Migration Guide
(I really hope nobody was using this on uninitialized entities where
sufficiently tortured `unsafe` could could technically notice that this
has changed.)
# Objective
After #9002, it seems that "single shot" animations were broken. When
completing, they would reset to their initial value. Which is generally
not what you want.
- Fixes#10480
## Solution
Avoid `%`-ing the animation after the number of completions exceeds the
specified one. Instead, we early-return. This is also true when the
player is playing in reverse.
---
## Changelog
- Avoid resetting animations after `Repeat::Never` animation completion.
# Objective
Fixes an issue where Bevy will look for `.meta` files in the root of the
server instead of `imported_assets/Default` on the web.
## Solution
`self.root_path.join` was seemingly forgotten in the `read_meta`
function on `HttpWasmAssetReader`, though it was included in the `read`
function. This PR simply adds the missing function call.
# Objective
* In Bevy 0.11 asset loaders used `anyhow::Error` for returning errors.
In Bevy 0.12 `AssetLoader` (and `AssetSaver`) have associated `Error`
type. Unfortunately it's type bounds does not allow `anyhow::Error` to
be used despite migration guide claiming otherwise. This makes migration
to 0.12 more challenging. Solve this by changing type bounds for
associated `Error` type.
* Fix#10350
## Solution
Change associated `Error` type bounds to require `Into<Box<dyn
std::error::Error + Send + Sync + 'static>>` to be implemented instead
of `std::error::Error + Send + Sync + 'static`. Both `anyhow::Error` and
errors generated by `thiserror` seems to be fine with such type bound.
---
## Changelog
### Fixed
* Fixed compatibility with `anyhow::Error` in `AssetLoader` and
`AssetSaver` associated `Error` type
# Objective
Fixes#10439
`Timer::percent()` and `Timer::percent_left()` return values in the
range of 0.0 to 1.0, even though their names contain "percent".
These functions should be renamed for clarity.
## Solution
- Rename `Timer::percent()` to `Timer::fraction()`
- Rename `Timer::percent_left()` to `Timer::fraction_remaining()`
---
## Changelog
### Changed
- Renamed `Timer::percent()` to `Timer::fraction()`
- Renamed `Timer::percent_left()` to `Timer::fraction_remaining()`
## Migration Guide
- `Timer::percent()` has been renamed to `Timer::fraction()`
- `Timer::percent_left()` has been renamed to
`Timer::fraction_remaining()`
# Objective
This is similar to #10439.
`Time::<Fixed>::overstep_percentage()` and
`Time::<Fixed>::overstep_percentage_f64()` returns values from 0.0 to
1.0, but their names use the word "percentage". These function names
make it easy to misunderstand that they return values from 0.0 to 100.0.
To avoid confusion, these functions should be renamed to
"`overstep_fraction(_f64)`".
## Solution
Rename them.
---
## Changelog
### Changed
- Renamed `Time::<Fixed>::overstep_percentage()` to
`Time::<Fixed>::overstep_fraction()`
- Renamed `Time::<Fixed>::overstep_percentage_f64()` to
`Time::<Fixed>::overstep_fraction_f64()`
## Migration Guide
- `Time::<Fixed>::overstep_percentage()` has been renamed to
`Time::<Fixed>::overstep_fraction()`
- `Time::<Fixed>::overstep_percentage_f64()` has been renamed to
`Time::<Fixed>::overstep_fraction_f64()`
# Objective
Hot reloading shader imports on windows is currently broken due to
inconsistent `/` and `\` usage ('/` is used in the user facing APIs and
`\` is produced by notify-rs (and likely other OS apis).
Fixes#10500
## Solution
Standardize import paths when loading a `Shader`. The correct long term
fix is to standardize AssetPath on `/`-only, but this is the right scope
of fix for a patch release.
---------
Co-authored-by: François <mockersf@gmail.com>
# Objective
- `CommandQueue::apply` calculates the address of the end of the
internal buffer as a `usize` rather than as a pointer, requiring two
casts of `cursor` to `usize`. Casting pointers to integers is generally
discouraged and may also prevent optimizations. It's also unnecessary
here.
## Solution
- Calculate the end address as a pointer rather than a `usize`.
Small note:
A trivial translation of the old code to use pointers would have
computed `end_addr` as `cursor.add(self.bytes.len())`, which is not
wrong but is an additional `unsafe` operation that also needs to be
properly documented and proven correct. However this operation is
already implemented in the form of the safe `as_mut_ptr_range`, so I
just used that.
# Objective
- The docs on `AssetPath::try_parse` say that it will return an error
when the string is malformed, but it actually just `.unwrap()`s the
result.
## Solution
- Use `?` instead of unwrapping the result.
# Objective
Calling `RenderDevice::poll` requires an instance of `wgpu::Maintain`,
but the type was not reexported by bevy. Working around it requires
adding a dependency on `wgpu`, since bevy does not reexport the `wgpu`
crate as a whole anywhere.
## Solution
Reexport `wgpu::Maintain` in `render_resource`, where the other wgpu
types are reexported.
# Objective
There is an if statement checking if a node is present in a graph
moments after it explicitly being added.
Unless the edge function has super weird side effects and the tests
don't pass, this is unnecessary.
## Solution
Removed it
# Objective
- Allow registration of one-shot systems when those systems have already
been `Box`ed.
- Needed for `bevy_eventlisteners` which allows adding event listeners
with callbacks in normal systems. The current one shot system
implementation requires systems be registered from an exclusive system,
and that those systems be passed in as types that implement
`IntoSystem`. However, the eventlistener callback crate allows users to
define their callbacks in normal systems, by boxing the system and
deferring initialization to an exclusive system.
## Solution
- Separate the registration of the system from the boxing of the system.
This is non-breaking, and adds a new method.
---
## Changelog
- Added `World::register_boxed_system` to allow registration of
already-boxed one shot systems.
# Objective
Had an issue where I had `VisibilityBundle` inside a bundle that
implements `Clone`, but since `VisibilityBundle` doesn't implement
`Clone` that wasn't possible. This PR fixes that.
## Solution
Implement `Clone` for `VisibilityBundle` by deriving it. And also
`SpatialBundle` too because why not.
---
## Changelog
- Added implementation for `Clone` on `VisibilityBundle` and
`SpatialBundle`.
# Objective
Fix a shader error that happens when using pbr morph targets.
## Solution
Fix the function name in the `prepass.wgsl` shader, which is incorrectly
prefixed with `morph::` (added in
61bad4eb57 (diff-97e4500f0a36bc6206d7b1490c8dd1a69459ee39dc6822eb9b2f7b160865f49fR42)).
This section of the shader is only enabled when using morph targets, so
it seems like there are no tests / examples using it?
# Objective
- Entities with both a `BackgroundColor` and a
`Handle<CustomUiMaterial>` are extracted by both pipelines and results
in entities being overwritten in the render world
- Fixes#10431
## Solution
- Ignore entities with `BackgroundColor` when extracting ui material
entities, and document that limit
# Objective
- There is a specialized hasher for entities:
[`EntityHashMap`](https://docs.rs/bevy/latest/bevy/utils/type.EntityHashMap.html)
- [`EntityMapper`] currently uses a normal `HashMap<Entity, Entity>`
- Fixes#10391
## Solution
- Replace the normal `HashMap` with the more performant `EntityHashMap`
## Questions
- This does change public API. Should a system be implemented to help
migrate code?
- Perhaps an `impl From<HashMap<K, V, S>> for EntityHashMap<K, V>`
- I updated to docs for each function that I changed, but I may have
missed something
---
## Changelog
- Changed `EntityMapper` to use `EntityHashMap` instead of normal
`HashMap`
## Migration Guide
If you are using the following types, update their listed methods to use
the new `EntityHashMap`. `EntityHashMap` has the same methods as the
normal `HashMap`, so you just need to replace the name.
### `EntityMapper`
- `get_map`
- `get_mut_map`
- `new`
- `world_scope`
### `ReflectMapEntities`
- `map_all_entities`
- `map_entities`
- `write_to_world`
### `InstanceInfo`
- `entity_map`
- This is a property, not a method.
---
This is my first time contributing in a while, and I'm not familiar with
the usage of `EntityMapper`. I changed the type definition and fixed all
errors, but there may have been things I've missed. Please keep an eye
out for me!
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
- Fixes#10209
- Assets should work in single threaded
## Solution
- In single threaded mode, don't use `async_fs` but fallback on
`std::fs` with a thin layer to mimic the async API
- file `file_asset.rs` is the async imps from `mod.rs`
- file `sync_file_asset.rs` is the same with `async_fs` APIs replaced by
`std::fs`
- which module is used depends on the `multi-threaded` feature
---------
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
Fixes a small typo in `bevy_window/src/window.rs`
## Solution
Change `Should be used instead 'scale_factor' when set.` to `Should be
used instead of 'scale_factor' when set.`
# Objective
- Adopt #10239 to get it in time for the release
- Fix accessibility on macOS and linux
## Solution
- call `on_event` from AcccessKit adapter on winit events
---------
Co-authored-by: Nolan Darilek <nolan@thewordnerd.info>
Co-authored-by: Alice Cecile <alice.i.cecil@gmail.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
- Changes the default clear color to match the code block color on
Bevy's website.
## Solution
- Changed the clear color, updated text in examples to ensure adequate
contrast. Inconsistent usage of white text color set to use the default
color instead, which is already white.
- Additionally, updated the `3d_scene` example to make it look a bit
better, and use bevy's branding colors.
![image](https://github.com/bevyengine/bevy/assets/2632925/540a22c0-826c-4c33-89aa-34905e3e313a)
# Objective
Fixes https://github.com/bevyengine/bevy/issues/9077 (see this issue for
motivations)
## Solution
Implement 1 and 2 of the "How to fix it" section of
https://github.com/bevyengine/bevy/issues/9077
`update_directional_light_cascades` is split into
`clear_directional_light_cascades` and a generic
`build_directional_light_cascades`, to clear once and potentially insert
many times.
---
## Changelog
`DirectionalLight`'s computation is now generic over `CameraProjection`
and can work with custom camera projections.
## Migration Guide
If you have a component `MyCustomProjection` that implements
`CameraProjection`:
- You need to implement a new required associated method,
`get_frustum_corners`, returning an array of the corners of a subset of
the frustum with given `z_near` and `z_far`, in local camera space.
- You can now add the
`build_directional_light_cascades::<MyCustomProjection>` system in
`SimulationLightSystems::UpdateDirectionalLightCascades` after
`clear_directional_light_cascades` for your projection to work with
directional lights.
---------
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
Bevy's default bias values for directional and spot lights currently
cause significant artifacts. We should fix that so shadows look good by
default!
This is a less controversial/invasive alternative to #10188, which might
enable us to keep the default bias value low, but also has its own sets
of concerns and caveats that make it a risky choice for Bevy 0.12.
## Solution
Bump the default normal bias from `0.6` to `1.8`. There is precedent for
values in this general area as Godot has a default normal bias of `2.0`.
### Before
![image](https://github.com/superdump/bevy/assets/2694663/a5828011-33fc-4427-90ed-f093d7389053)
### After
![image](https://github.com/bevyengine/bevy/assets/2694663/0f2b16b0-c116-41ab-9886-1ace9e00efd6)
## Migration Guide
The default `shadow_normal_bias` value for `DirectionalLight` and
`SpotLight` has changed to accommodate artifacts introduced with the new
shadow PCF changes. It is unlikely (especially given the new PCF shadow
behaviors with these values), but you might need to manually tweak this
value if your scene requires a lower bias and it relied on the previous
default value.
# Objective
Reimplement #8793 on top of the recent rendering changes.
## Solution
The batch creation logic is quite convoluted, but I tested it on enough
examples to convince myself that it works.
The initial value of `batch_image_handle` is changed from
`HandleId::Id(Uuid::nil(), u64::MAX)` to `DEFAULT_IMAGE_HANDLE.id()`,
which allowed me to make the if-block simpler I think.
The default image from `DEFAULT_IMAGE_HANDLE` is always inserted into
`UiImageBindGroups` even if it's not used. I tried to add a check so
that it would be only inserted when there is only one batch using the
default image but this crashed.
---
## Changelog
`prepare_uinodes`
* Changed the initial value of `batch_image_handle` to
`DEFAULT_IMAGE_HANDLE.id()`.
* The default image is added to the UI image bind groups before
assembling the batches.
* A new `UiBatch` isn't created when the next `ExtractedUiNode`s image
is set to `DEFAULT_IMAGE_HANDLE` (unless it is the first item in the UI
phase items list).
# Objective
fix crash / misbehaviour when `DeferredPrepass` is used without
`DepthPrepass`.
- Deferred lighting requires the depth prepass texture to be present, so
that the depth texture is available for binding. without it the deferred
lighting pass will use 0 for depth of all meshes.
- When `DeferredPrepass` is used without other prepass markers, and with
any materials that use `OpaqueRenderMode::Forward`, those entities will
try to queue to the `Opaque3dPrepass` render phase, which doesn't exist,
causing a crash.
## Solution
- check if the prepass phases exist before queueing
- generate prepass textures if `Opaque3dDeferred` is present
- add a note to the DeferredPrepass marker to note that DepthPrepass is
also required by the default deferred lighting pass
- also changed some `With<T>.is_some()`s to `Has<T>`s
# Objective
I was working with forward rendering prepass fragment shaders and ran
into an issue of not being able to access vertex colors in the prepass.
I was able to access vertex colors in regular fragment shaders as well
as in deferred shaders.
## Solution
It seems like this `if` was nested unintentionally as moving it outside
of the `deferred` block works.
---
## Changelog
Enable vertex colors in forward rendering prepass fragment shaders
# Objective
Alternative to #7310
## Solution
Implemented the suggestion from
https://github.com/bevyengine/bevy/pull/7310#discussion_r1083356655
I am guessing that these were originally split as an optimization, but I
am not sure since I believe the original author of the code is the one
speculating about combining them up there.
## Benchmarks
I ran three benchmarks to compare main, this PR, and the approach from
#7310
([updated](https://github.com/rparrett/bevy/commits/rebased-parallel-check-visibility)
to the same commit on main).
This seems to perform slightly better than main in scenarios where most
entities have AABBs, and a bit worse when they don't (`many_lights`).
That seems to make sense to me.
Either way, the difference is ~-20 microseconds in the more common
scenarios or ~+100 microseconds in the less common scenario. I would
speculate that this might perform **very slightly** worse in
single-threaded scenarios.
Benches were run in release mode for 2000 frames while capturing a trace
with tracy.
| bench | commit | check_visibility_system mean μs |
| -- | -- | -- |
| many_cubes | main | 929.5 |
| many_cubes | this | 914.0 |
| many_cubes | 7310 | 1003.5 |
| | |
| many_foxes | main | 191.6 |
| many_foxes | this | 173.2 |
| many_foxes | 7310 | 167.9 |
| | |
| many_lights | main | 619.3 |
| many_lights | this | 703.7 |
| many_lights | 7310 | 842.5 |
## Notes
Technically this behaves slightly differently -- prior to this PR, view
visibility was determined even for entities without `GlobalTransform`. I
don't think this has any practical impact though.
IMO, I don't think we need to do this. But I opened a PR because it
seemed like the handiest way to share the code / benchmarks.
## TODO
I have done some rudimentary testing with the examples above, but I can
do some screenshot diffing if it seems like we want to do this.
# Objective
- Revert #10296
## Solution
- Avoid implementing `Display` without a justification
- `Display` implementation is a guarantee without a direct use, takes
additional time to compile and require work to maintain
- `Debug`, `Reflect` or `Serialize` should cover all needs
# Objective
The `BuildWorldChildren` API was missing several methods that exist in
`BuildChildren`.
## Solution
Added the methods (and tests) for consistency.
# Objective
If we add the stack index to `Node` then we don't need to walk the
`UiStack` repeatedly during extraction.
## Solution
Add a field `stack_index` to `Node`.
Update it in `ui_stack_system`.
Iterate queries directly in the UI's extraction systems.
### Benchmarks
```
cargo run --profile stress-test --features trace_tracy --example many_buttons -- --no-text --no-borders
```
frames (yellow this PR, red main):
<img width="447" alt="frames-per-second"
src="https://github.com/bevyengine/bevy/assets/27962798/385c0ccf-c257-42a2-b736-117542d56eff">
`ui_stack_system`:
<img width="585" alt="ui-stack-system"
src="https://github.com/bevyengine/bevy/assets/27962798/2916cc44-2887-4c3b-a144-13250d84f7d5">
extract schedule:
<img width="469" alt="extract-schedule"
src="https://github.com/bevyengine/bevy/assets/27962798/858d4ab4-d99f-48e8-b153-1c92f51e0743">
---
## Changelog
* Added the field `stack_index` to `Node`.
* `ui_stack_system` updates `Node::stack_index` after a new `UiStack` is
generated.
* The UI's extraction functions iterate a query directly rather than
walking the `UiStack` and doing lookups.
# 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
- We need to check multiple times if a color is fully transparent, e.g.
for performance optimizations.
- Make code more readable.
- Reduce code duplication, to simplify making changes if needed (e.g. if
we need to take floating point weirdness into account later on).
## Solution
- Introduce a new `Color::is_fully_transparent` helper function to
determine if the alpha of a color is 0.
- Use the helper function in our UI rendering code.
---
## Changelog
- Added `Color::is_fully_transparent` helper function.
---------
Co-authored-by: François <mockersf@gmail.com>
# Objective
Right now, we flip the `world_normal` in response to `double_sided &&
!is_front`, however when calculating `N` from tangents and the normal
map, we don't flip the normal read from the normal map, which produces
extremely weird results.
## Solution
- Pass `double_sided` and `is_front` flags to the
`apply_normal_mapping()` function and use them to conditionally flip
`Nt`
## Comparison
Note: These are from a custom scene running with the `transmission`
branch, (#8015) I noticed lighting got pretty weird for the back side of
translucent `double_sided` materials whenever I added a normal map.
### Before
<img width="1392" alt="Screenshot 2023-10-31 at 01 26 06"
src="https://github.com/bevyengine/bevy/assets/418473/d5f8c9c3-aca1-4c2f-854d-f0d0fd2fb19a">
### After
<img width="1392" alt="Screenshot 2023-10-31 at 01 25 42"
src="https://github.com/bevyengine/bevy/assets/418473/fa0e1aa2-19ad-4c27-bb08-37299d97971c">
---
## Changelog
- Fixed a bug where `StandardMaterial::double_sided` would interact
incorrectly with normal maps, producing broken results.