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6 commits

Author SHA1 Message Date
re0312
04aedf12fa
optimize batch_and_prepare_render_phase (#11323)
# Objective

- since #9685  ,bevy introduce automatic batching of draw commands, 
- `batch_and_prepare_render_phase` take the responsibility for batching
`phaseItem`,
- `GetBatchData` trait is used for indentify each phaseitem how to
batch. it defines a associated type `Data `used for Query to fetch data
from world.

- however,the impl of `GetBatchData ` in bevy always set ` type
Data=Entity` then we acually get following code
`let entity:Entity =query.get(item.entity())` that cause unnecessary
overhead .

## Solution

- remove associated type `Data ` and `Filter` from `GetBatchData `,
- change the type of the `query_item ` parameter in get_batch_data from`
Self::Data` to `Entity`.
- `batch_and_prepare_render_phase ` no longer takes a query using
`F::Data, F::Filter`
- `get_batch_data `now returns `Option<(Self::BufferData,
Option<Self::CompareData>)>`

---

## Performance
based in main merged with #11290 
Window 11 ,Intel 13400kf, NV 4070Ti

![image](https://github.com/bevyengine/bevy/assets/45868716/f63b9d98-6aee-4057-a2c7-a2162b2db765)
frame time from 3.34ms to 3 ms,  ~ 10%


![image](https://github.com/bevyengine/bevy/assets/45868716/a06eea9c-f79e-4324-8392-8d321560c5ba)
`batch_and_prepare_render_phase` from 800us ~ 400 us  

## Migration Guide
trait `GetBatchData` no longer hold associated type  `Data `and `Filter`
`get_batch_data` `query_item `type from `Self::Data` to `Entity` and
return `Option<(Self::BufferData, Option<Self::CompareData>)>`
`batch_and_prepare_render_phase`  should not have a query
2024-01-20 09:30:44 +00:00
Mantas
5af2f022d8
Rename WorldQueryData & WorldQueryFilter to QueryData & QueryFilter (#10779)
# Rename `WorldQueryData` & `WorldQueryFilter` to `QueryData` &
`QueryFilter`

Fixes #10776 

## Solution

Traits `WorldQueryData` & `WorldQueryFilter` were renamed to `QueryData`
and `QueryFilter`, respectively. Related Trait types were also renamed.

---

## Changelog

- Trait `WorldQueryData` has been renamed to `QueryData`. Derive macro's
`QueryData` attribute `world_query_data` has been renamed to
`query_data`.
- Trait `WorldQueryFilter` has been renamed to `QueryFilter`. Derive
macro's `QueryFilter` attribute `world_query_filter` has been renamed to
`query_filter`.
- Trait's `ExtractComponent` type `Query` has been renamed to `Data`.
- Trait's `GetBatchData` types `Query` & `QueryFilter` has been renamed
to `Data` & `Filter`, respectively.
- Trait's `ExtractInstance` type `Query` has been renamed to `Data`.
- Trait's `ViewNode` type `ViewQuery` has been renamed to `ViewData`.
- Trait's `RenderCommand` types `ViewWorldQuery` & `ItemWorldQuery` has
been renamed to `ViewData` & `ItemData`, respectively.

## Migration Guide

Note: if merged before 0.13 is released, this should instead modify the
migration guide of #10776 with the updated names.

- Rename `WorldQueryData` & `WorldQueryFilter` trait usages to
`QueryData` & `QueryFilter` and their respective derive macro attributes
`world_query_data` & `world_query_filter` to `query_data` &
`query_filter`.
- Rename the following trait type usages:
  - Trait's `ExtractComponent` type `Query` to `Data`.
  - Trait's `GetBatchData` type `Query` to `Data`.
  - Trait's `ExtractInstance` type `Query` to `Data`.
  - Trait's `ViewNode` type `ViewQuery` to `ViewData`'
- Trait's `RenderCommand` types `ViewWolrdQuery` & `ItemWorldQuery` to
`ViewData` & `ItemData`, respectively.

```rust
// Before
#[derive(WorldQueryData)]
#[world_query_data(derive(Debug))]
struct EmptyQuery {
    empty: (),
}

// After
#[derive(QueryData)]
#[query_data(derive(Debug))]
struct EmptyQuery {
    empty: (),
}

// Before
#[derive(WorldQueryFilter)]
struct CustomQueryFilter<T: Component, P: Component> {
    _c: With<ComponentC>,
    _d: With<ComponentD>,
    _or: Or<(Added<ComponentC>, Changed<ComponentD>, Without<ComponentZ>)>,
    _generic_tuple: (With<T>, With<P>),
}

// After
#[derive(QueryFilter)]
struct CustomQueryFilter<T: Component, P: Component> {
    _c: With<ComponentC>,
    _d: With<ComponentD>,
    _or: Or<(Added<ComponentC>, Changed<ComponentD>, Without<ComponentZ>)>,
    _generic_tuple: (With<T>, With<P>),
}

// Before
impl ExtractComponent for ContrastAdaptiveSharpeningSettings {
    type Query = &'static Self;
    type Filter = With<Camera>;
    type Out = (DenoiseCAS, CASUniform);

    fn extract_component(item: QueryItem<Self::Query>) -> Option<Self::Out> {
        //...
    }
}

// After
impl ExtractComponent for ContrastAdaptiveSharpeningSettings {
    type Data = &'static Self;
    type Filter = With<Camera>;
    type Out = (DenoiseCAS, CASUniform);

    fn extract_component(item: QueryItem<Self::Data>) -> Option<Self::Out> {
        //...
    }
}

// Before
impl GetBatchData for MeshPipeline {
    type Param = SRes<RenderMeshInstances>;
    type Query = Entity;
    type QueryFilter = With<Mesh3d>;
    type CompareData = (MaterialBindGroupId, AssetId<Mesh>);
    type BufferData = MeshUniform;

    fn get_batch_data(
        mesh_instances: &SystemParamItem<Self::Param>,
        entity: &QueryItem<Self::Query>,
    ) -> (Self::BufferData, Option<Self::CompareData>) {
        // ....
    }
}

// After
impl GetBatchData for MeshPipeline {
    type Param = SRes<RenderMeshInstances>;
    type Data = Entity;
    type Filter = With<Mesh3d>;
    type CompareData = (MaterialBindGroupId, AssetId<Mesh>);
    type BufferData = MeshUniform;

    fn get_batch_data(
        mesh_instances: &SystemParamItem<Self::Param>,
        entity: &QueryItem<Self::Data>,
    ) -> (Self::BufferData, Option<Self::CompareData>) {
        // ....
    }
}

// Before
impl<A> ExtractInstance for AssetId<A>
where
    A: Asset,
{
    type Query = Read<Handle<A>>;
    type Filter = ();

    fn extract(item: QueryItem<'_, Self::Query>) -> Option<Self> {
        Some(item.id())
    }
}

// After
impl<A> ExtractInstance for AssetId<A>
where
    A: Asset,
{
    type Data = Read<Handle<A>>;
    type Filter = ();

    fn extract(item: QueryItem<'_, Self::Data>) -> Option<Self> {
        Some(item.id())
    }
}

// Before
impl ViewNode for PostProcessNode {
    type ViewQuery = (
        &'static ViewTarget,
        &'static PostProcessSettings,
    );

    fn run(
        &self,
        _graph: &mut RenderGraphContext,
        render_context: &mut RenderContext,
        (view_target, _post_process_settings): QueryItem<Self::ViewQuery>,
        world: &World,
    ) -> Result<(), NodeRunError> {
        // ...
    }
}

// After
impl ViewNode for PostProcessNode {
    type ViewData = (
        &'static ViewTarget,
        &'static PostProcessSettings,
    );

    fn run(
        &self,
        _graph: &mut RenderGraphContext,
        render_context: &mut RenderContext,
        (view_target, _post_process_settings): QueryItem<Self::ViewData>,
        world: &World,
    ) -> Result<(), NodeRunError> {
        // ...
    }
}

// Before
impl<P: CachedRenderPipelinePhaseItem> RenderCommand<P> for SetItemPipeline {
    type Param = SRes<PipelineCache>;
    type ViewWorldQuery = ();
    type ItemWorldQuery = ();
    #[inline]
    fn render<'w>(
        item: &P,
        _view: (),
        _entity: (),
        pipeline_cache: SystemParamItem<'w, '_, Self::Param>,
        pass: &mut TrackedRenderPass<'w>,
    ) -> RenderCommandResult {
        // ...
    }
}

// After
impl<P: CachedRenderPipelinePhaseItem> RenderCommand<P> for SetItemPipeline {
    type Param = SRes<PipelineCache>;
    type ViewData = ();
    type ItemData = ();
    #[inline]
    fn render<'w>(
        item: &P,
        _view: (),
        _entity: (),
        pipeline_cache: SystemParamItem<'w, '_, Self::Param>,
        pass: &mut TrackedRenderPass<'w>,
    ) -> RenderCommandResult {
        // ...
    }
}
```
2023-12-12 19:45:50 +00:00
Mark Wainwright
f0a8994f55
Split WorldQuery into WorldQueryData and WorldQueryFilter (#9918)
# Objective

- Fixes #7680
- This is an updated for https://github.com/bevyengine/bevy/pull/8899
which had the same objective but fell a long way behind the latest
changes


## Solution

The traits `WorldQueryData : WorldQuery` and `WorldQueryFilter :
WorldQuery` have been added and some of the types and functions from
`WorldQuery` has been moved into them.

`ReadOnlyWorldQuery` has been replaced with `ReadOnlyWorldQueryData`. 

`WorldQueryFilter` is safe (as long as `WorldQuery` is implemented
safely).

`WorldQueryData` is unsafe - safely implementing it requires that
`Self::ReadOnly` is a readonly version of `Self` (this used to be a
safety requirement of `WorldQuery`)

The type parameters `Q` and `F` of `Query` must now implement
`WorldQueryData` and `WorldQueryFilter` respectively.

This makes it impossible to accidentally use a filter in the data
position or vice versa which was something that could lead to bugs.
~~Compile failure tests have been added to check this.~~

It was previously sometimes useful to use `Option<With<T>>` in the data
position. Use `Has<T>` instead in these cases.

The `WorldQuery` derive macro has been split into separate derive macros
for `WorldQueryData` and `WorldQueryFilter`.

Previously it was possible to derive both `WorldQuery` for a struct that
had a mixture of data and filter items. This would not work correctly in
some cases but could be a useful pattern in others. *This is no longer
possible.*

---

## Notes

- The changes outside of `bevy_ecs` are all changing type parameters to
the new types, updating the macro use, or replacing `Option<With<T>>`
with `Has<T>`.

- All `WorldQueryData` types always returned `true` for `IS_ARCHETYPAL`
so I moved it to `WorldQueryFilter` and
replaced all calls to it with `true`. That should be the only logic
change outside of the macro generation code.

- `Changed<T>` and `Added<T>` were being generated by a macro that I
have expanded. Happy to revert that if desired.

- The two derive macros share some functions for implementing
`WorldQuery` but the tidiest way I could find to implement them was to
give them a ton of arguments and ask clippy to ignore that.

## Changelog

### Changed
- Split `WorldQuery` into `WorldQueryData` and `WorldQueryFilter` which
now have separate derive macros. It is not possible to derive both for
the same type.
- `Query` now requires that the first type argument implements
`WorldQueryData` and the second implements `WorldQueryFilter`

## Migration Guide

- Update derives

```rust
// old
#[derive(WorldQuery)]
#[world_query(mutable, derive(Debug))]
struct CustomQuery {
    entity: Entity,
    a: &'static mut ComponentA
}

#[derive(WorldQuery)]
struct QueryFilter {
    _c: With<ComponentC>
}

// new 
#[derive(WorldQueryData)]
#[world_query_data(mutable, derive(Debug))]
struct CustomQuery {
    entity: Entity,
    a: &'static mut ComponentA,
}

#[derive(WorldQueryFilter)]
struct QueryFilter {
    _c: With<ComponentC>
}
```
- Replace `Option<With<T>>` with `Has<T>`

```rust
/// old
fn my_system(query: Query<(Entity, Option<With<ComponentA>>)>)
{
  for (entity, has_a_option) in query.iter(){
    let has_a:bool = has_a_option.is_some();
    //todo!()
  }
}

/// new
fn my_system(query: Query<(Entity, Has<ComponentA>)>)
{
  for (entity, has_a) in query.iter(){
    //todo!()
  }
}
```

- Fix queries which had filters in the data position or vice versa.

```rust
// old
fn my_system(query: Query<(Entity, With<ComponentA>)>)
{
  for (entity, _) in query.iter(){
  //todo!()
  }
}

// new
fn my_system(query: Query<Entity, With<ComponentA>>)
{
  for entity in query.iter(){
  //todo!()
  }
}

// old
fn my_system(query: Query<AnyOf<(&ComponentA, With<ComponentB>)>>)
{
  for (entity, _) in query.iter(){
  //todo!()
  }
}

// new
fn my_system(query: Query<Option<&ComponentA>, Or<(With<ComponentA>, With<ComponentB>)>>)
{
  for entity in query.iter(){
  //todo!()
  }
}

```

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2023-11-28 03:56:07 +00:00
Marco Buono
44928e0df4
StandardMaterial Light Transmission (#8015)
# 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`
2023-10-31 20:59:02 +00:00
Robert Swain
b6ead2be95
Use EntityHashMap<Entity, T> for render world entity storage for better performance (#9903)
# Objective

- Improve rendering performance, particularly by avoiding the large
system commands costs of using the ECS in the way that the render world
does.

## Solution

- Define `EntityHasher` that calculates a hash from the
`Entity.to_bits()` by `i | (i.wrapping_mul(0x517cc1b727220a95) << 32)`.
`0x517cc1b727220a95` is something like `u64::MAX / N` for N that gives a
value close to π and that works well for hashing. Thanks for @SkiFire13
for the suggestion and to @nicopap for alternative suggestions and
discussion. This approach comes from `rustc-hash` (a.k.a. `FxHasher`)
with some tweaks for the case of hashing an `Entity`. `FxHasher` and
`SeaHasher` were also tested but were significantly slower.
- Define `EntityHashMap` type that uses the `EntityHashser`
- Use `EntityHashMap<Entity, T>` for render world entity storage,
including:
- `RenderMaterialInstances` - contains the `AssetId<M>` of the material
associated with the entity. Also for 2D.
- `RenderMeshInstances` - contains mesh transforms, flags and properties
about mesh entities. Also for 2D.
- `SkinIndices` and `MorphIndices` - contains the skin and morph index
for an entity, respectively
  - `ExtractedSprites`
  - `ExtractedUiNodes`

## Benchmarks

All benchmarks have been conducted on an M1 Max connected to AC power.
The tests are run for 1500 frames. The 1000th frame is captured for
comparison to check for visual regressions. There were none.

### 2D Meshes

`bevymark --benchmark --waves 160 --per-wave 1000 --mode mesh2d`

#### `--ordered-z`

This test spawns the 2D meshes with z incrementing back to front, which
is the ideal arrangement allocation order as it matches the sorted
render order which means lookups have a high cache hit rate.

<img width="1112" alt="Screenshot 2023-09-27 at 07 50 45"
src="https://github.com/bevyengine/bevy/assets/302146/e140bc98-7091-4a3b-8ae1-ab75d16d2ccb">

-39.1% median frame time.

#### Random

This test spawns the 2D meshes with random z. This not only makes the
batching and transparent 2D pass lookups get a lot of cache misses, it
also currently means that the meshes are almost certain to not be
batchable.

<img width="1108" alt="Screenshot 2023-09-27 at 07 51 28"
src="https://github.com/bevyengine/bevy/assets/302146/29c2e813-645a-43ce-982a-55df4bf7d8c4">

-7.2% median frame time.

### 3D Meshes

`many_cubes --benchmark`

<img width="1112" alt="Screenshot 2023-09-27 at 07 51 57"
src="https://github.com/bevyengine/bevy/assets/302146/1a729673-3254-4e2a-9072-55e27c69f0fc">

-7.7% median frame time.

### Sprites

**NOTE: On `main` sprites are using `SparseSet<Entity, T>`!**

`bevymark --benchmark --waves 160 --per-wave 1000 --mode sprite`

#### `--ordered-z`

This test spawns the sprites with z incrementing back to front, which is
the ideal arrangement allocation order as it matches the sorted render
order which means lookups have a high cache hit rate.

<img width="1116" alt="Screenshot 2023-09-27 at 07 52 31"
src="https://github.com/bevyengine/bevy/assets/302146/bc8eab90-e375-4d31-b5cd-f55f6f59ab67">

+13.0% median frame time.

#### Random

This test spawns the sprites with random z. This makes the batching and
transparent 2D pass lookups get a lot of cache misses.

<img width="1109" alt="Screenshot 2023-09-27 at 07 53 01"
src="https://github.com/bevyengine/bevy/assets/302146/22073f5d-99a7-49b0-9584-d3ac3eac3033">

+0.6% median frame time.

### UI

**NOTE: On `main` UI is using `SparseSet<Entity, T>`!**

`many_buttons`

<img width="1111" alt="Screenshot 2023-09-27 at 07 53 26"
src="https://github.com/bevyengine/bevy/assets/302146/66afd56d-cbe4-49e7-8b64-2f28f6043d85">

+15.1% median frame time.

## Alternatives

- Cart originally suggested trying out `SparseSet<Entity, T>` and indeed
that is slightly faster under ideal conditions. However,
`PassHashMap<Entity, T>` has better worst case performance when data is
randomly distributed, rather than in sorted render order, and does not
have the worst case memory usage that `SparseSet`'s dense `Vec<usize>`
that maps from the `Entity` index to sparse index into `Vec<T>`. This
dense `Vec` has to be as large as the largest Entity index used with the
`SparseSet`.
- I also tested `PassHashMap<u32, T>`, intending to use `Entity.index()`
as the key, but this proved to sometimes be slower and mostly no
different.
- The only outstanding approach that has not been implemented and tested
is to _not_ clear the render world of its entities each frame. That has
its own problems, though they could perhaps be solved.
- Performance-wise, if the entities and their component data were not
cleared, then they would incur table moves on spawn, and should not
thereafter, rather just their component data would be overwritten.
Ideally we would have a neat way of either updating data in-place via
`&mut T` queries, or inserting components if not present. This would
likely be quite cumbersome to have to remember to do everywhere, but
perhaps it only needs to be done in the more performance-sensitive
systems.
- The main problem to solve however is that we want to both maintain a
mapping between main world entities and render world entities, be able
to run the render app and world in parallel with the main app and world
for pipelined rendering, and at the same time be able to spawn entities
in the render world in such a way that those Entity ids do not collide
with those spawned in the main world. This is potentially quite
solvable, but could well be a lot of ECS work to do it in a way that
makes sense.

---

## Changelog

- Changed: Component data for entities to be drawn are no longer stored
on entities in the render world. Instead, data is stored in a
`EntityHashMap<Entity, T>` in various resources. This brings significant
performance benefits due to the way the render app clears entities every
frame. Resources of most interest are `RenderMeshInstances` and
`RenderMaterialInstances`, and their 2D counterparts.

## Migration Guide

Previously the render app extracted mesh entities and their component
data from the main world and stored them as entities and components in
the render world. Now they are extracted into essentially
`EntityHashMap<Entity, T>` where `T` are structs containing an
appropriate group of data. This means that while extract set systems
will continue to run extract queries against the main world they will
store their data in hash maps. Also, systems in later sets will either
need to look up entities in the available resources such as
`RenderMeshInstances`, or maintain their own `EntityHashMap<Entity, T>`
for their own data.

Before:
```rust
fn queue_custom(
    material_meshes: Query<(Entity, &MeshTransforms, &Handle<Mesh>), With<InstanceMaterialData>>,
) {
    ...
    for (entity, mesh_transforms, mesh_handle) in &material_meshes {
        ...
    }
}
```

After:
```rust
fn queue_custom(
    render_mesh_instances: Res<RenderMeshInstances>,
    instance_entities: Query<Entity, With<InstanceMaterialData>>,
) {
    ...
    for entity in &instance_entities {
        let Some(mesh_instance) = render_mesh_instances.get(&entity) else { continue; };
        // The mesh handle in `AssetId<Mesh>` form, and the `MeshTransforms` can now
        // be found in `mesh_instance` which is a `RenderMeshInstance`
        ...
    }
}
```

---------

Co-authored-by: robtfm <50659922+robtfm@users.noreply.github.com>
2023-09-27 08:28:28 +00:00
Robert Swain
5c884c5a15
Automatic batching/instancing of draw commands (#9685)
# Objective

- Implement the foundations of automatic batching/instancing of draw
commands as the next step from #89
- NOTE: More performance improvements will come when more data is
managed and bound in ways that do not require rebinding such as mesh,
material, and texture data.

## Solution

- The core idea for batching of draw commands is to check whether any of
the information that has to be passed when encoding a draw command
changes between two things that are being drawn according to the sorted
render phase order. These should be things like the pipeline, bind
groups and their dynamic offsets, index/vertex buffers, and so on.
  - The following assumptions have been made:
- Only entities with prepared assets (pipelines, materials, meshes) are
queued to phases
- View bindings are constant across a phase for a given draw function as
phases are per-view
- `batch_and_prepare_render_phase` is the only system that performs this
batching and has sole responsibility for preparing the per-object data.
As such the mesh binding and dynamic offsets are assumed to only vary as
a result of the `batch_and_prepare_render_phase` system, e.g. due to
having to split data across separate uniform bindings within the same
buffer due to the maximum uniform buffer binding size.
- Implement `GpuArrayBuffer` for `Mesh2dUniform` to store Mesh2dUniform
in arrays in GPU buffers rather than each one being at a dynamic offset
in a uniform buffer. This is the same optimisation that was made for 3D
not long ago.
- Change batch size for a range in `PhaseItem`, adding API for getting
or mutating the range. This is more flexible than a size as the length
of the range can be used in place of the size, but the start and end can
be otherwise whatever is needed.
- Add an optional mesh bind group dynamic offset to `PhaseItem`. This
avoids having to do a massive table move just to insert
`GpuArrayBufferIndex` components.

## Benchmarks

All tests have been run on an M1 Max on AC power. `bevymark` and
`many_cubes` were modified to use 1920x1080 with a scale factor of 1. I
run a script that runs a separate Tracy capture process, and then runs
the bevy example with `--features bevy_ci_testing,trace_tracy` and
`CI_TESTING_CONFIG=../benchmark.ron` with the contents of
`../benchmark.ron`:
```rust
(
    exit_after: Some(1500)
)
```
...in order to run each test for 1500 frames.

The recent changes to `many_cubes` and `bevymark` added reproducible
random number generation so that with the same settings, the same rng
will occur. They also added benchmark modes that use a fixed delta time
for animations. Combined this means that the same frames should be
rendered both on main and on the branch.

The graphs compare main (yellow) to this PR (red).

### 3D Mesh `many_cubes --benchmark`

<img width="1411" alt="Screenshot 2023-09-03 at 23 42 10"
src="https://github.com/bevyengine/bevy/assets/302146/2088716a-c918-486c-8129-090b26fd2bc4">
The mesh and material are the same for all instances. This is basically
the best case for the initial batching implementation as it results in 1
draw for the ~11.7k visible meshes. It gives a ~30% reduction in median
frame time.

The 1000th frame is identical using the flip tool:

![flip many_cubes-main-mesh3d many_cubes-batching-mesh3d 67ppd
ldr](https://github.com/bevyengine/bevy/assets/302146/2511f37a-6df8-481a-932f-706ca4de7643)

```
     Mean: 0.000000
     Weighted median: 0.000000
     1st weighted quartile: 0.000000
     3rd weighted quartile: 0.000000
     Min: 0.000000
     Max: 0.000000
     Evaluation time: 0.4615 seconds
```

### 3D Mesh `many_cubes --benchmark --material-texture-count 10`

<img width="1404" alt="Screenshot 2023-09-03 at 23 45 18"
src="https://github.com/bevyengine/bevy/assets/302146/5ee9c447-5bd2-45c6-9706-ac5ff8916daf">
This run uses 10 different materials by varying their textures. The
materials are randomly selected, and there is no sorting by material
bind group for opaque 3D so any batching is 'random'. The PR produces a
~5% reduction in median frame time. If we were to sort the opaque phase
by the material bind group, then this should be a lot faster. This
produces about 10.5k draws for the 11.7k visible entities. This makes
sense as randomly selecting from 10 materials gives a chance that two
adjacent entities randomly select the same material and can be batched.

The 1000th frame is identical in flip:

![flip many_cubes-main-mesh3d-mtc10 many_cubes-batching-mesh3d-mtc10
67ppd
ldr](https://github.com/bevyengine/bevy/assets/302146/2b3a8614-9466-4ed8-b50c-d4aa71615dbb)

```
     Mean: 0.000000
     Weighted median: 0.000000
     1st weighted quartile: 0.000000
     3rd weighted quartile: 0.000000
     Min: 0.000000
     Max: 0.000000
     Evaluation time: 0.4537 seconds
```

### 3D Mesh `many_cubes --benchmark --vary-per-instance`

<img width="1394" alt="Screenshot 2023-09-03 at 23 48 44"
src="https://github.com/bevyengine/bevy/assets/302146/f02a816b-a444-4c18-a96a-63b5436f3b7f">
This run varies the material data per instance by randomly-generating
its colour. This is the worst case for batching and that it performs
about the same as `main` is a good thing as it demonstrates that the
batching has minimal overhead when dealing with ~11k visible mesh
entities.

The 1000th frame is identical according to flip:

![flip many_cubes-main-mesh3d-vpi many_cubes-batching-mesh3d-vpi 67ppd
ldr](https://github.com/bevyengine/bevy/assets/302146/ac5f5c14-9bda-4d1a-8219-7577d4aac68c)

```
     Mean: 0.000000
     Weighted median: 0.000000
     1st weighted quartile: 0.000000
     3rd weighted quartile: 0.000000
     Min: 0.000000
     Max: 0.000000
     Evaluation time: 0.4568 seconds
```

### 2D Mesh `bevymark --benchmark --waves 160 --per-wave 1000 --mode
mesh2d`

<img width="1412" alt="Screenshot 2023-09-03 at 23 59 56"
src="https://github.com/bevyengine/bevy/assets/302146/cb02ae07-237b-4646-ae9f-fda4dafcbad4">
This spawns 160 waves of 1000 quad meshes that are shaded with
ColorMaterial. Each wave has a different material so 160 waves currently
should result in 160 batches. This results in a 50% reduction in median
frame time.

Capturing a screenshot of the 1000th frame main vs PR gives:

![flip bevymark-main-mesh2d bevymark-batching-mesh2d 67ppd
ldr](https://github.com/bevyengine/bevy/assets/302146/80102728-1217-4059-87af-14d05044df40)

```
     Mean: 0.001222
     Weighted median: 0.750432
     1st weighted quartile: 0.453494
     3rd weighted quartile: 0.969758
     Min: 0.000000
     Max: 0.990296
     Evaluation time: 0.4255 seconds
```

So they seem to produce the same results. I also double-checked the
number of draws. `main` does 160000 draws, and the PR does 160, as
expected.

### 2D Mesh `bevymark --benchmark --waves 160 --per-wave 1000 --mode
mesh2d --material-texture-count 10`

<img width="1392" alt="Screenshot 2023-09-04 at 00 09 22"
src="https://github.com/bevyengine/bevy/assets/302146/4358da2e-ce32-4134-82df-3ab74c40849c">
This generates 10 textures and generates materials for each of those and
then selects one material per wave. The median frame time is reduced by
50%. Similar to the plain run above, this produces 160 draws on the PR
and 160000 on `main` and the 1000th frame is identical (ignoring the fps
counter text overlay).

![flip bevymark-main-mesh2d-mtc10 bevymark-batching-mesh2d-mtc10 67ppd
ldr](https://github.com/bevyengine/bevy/assets/302146/ebed2822-dce7-426a-858b-b77dc45b986f)

```
     Mean: 0.002877
     Weighted median: 0.964980
     1st weighted quartile: 0.668871
     3rd weighted quartile: 0.982749
     Min: 0.000000
     Max: 0.992377
     Evaluation time: 0.4301 seconds
```

### 2D Mesh `bevymark --benchmark --waves 160 --per-wave 1000 --mode
mesh2d --vary-per-instance`

<img width="1396" alt="Screenshot 2023-09-04 at 00 13 53"
src="https://github.com/bevyengine/bevy/assets/302146/b2198b18-3439-47ad-919a-cdabe190facb">
This creates unique materials per instance by randomly-generating the
material's colour. This is the worst case for 2D batching. Somehow, this
PR manages a 7% reduction in median frame time. Both main and this PR
issue 160000 draws.

The 1000th frame is the same:

![flip bevymark-main-mesh2d-vpi bevymark-batching-mesh2d-vpi 67ppd
ldr](https://github.com/bevyengine/bevy/assets/302146/a2ec471c-f576-4a36-a23b-b24b22578b97)

```
     Mean: 0.001214
     Weighted median: 0.937499
     1st weighted quartile: 0.635467
     3rd weighted quartile: 0.979085
     Min: 0.000000
     Max: 0.988971
     Evaluation time: 0.4462 seconds
```

### 2D Sprite `bevymark --benchmark --waves 160 --per-wave 1000 --mode
sprite`

<img width="1396" alt="Screenshot 2023-09-04 at 12 21 12"
src="https://github.com/bevyengine/bevy/assets/302146/8b31e915-d6be-4cac-abf5-c6a4da9c3d43">
This just spawns 160 waves of 1000 sprites. There should be and is no
notable difference between main and the PR.

### 2D Sprite `bevymark --benchmark --waves 160 --per-wave 1000 --mode
sprite --material-texture-count 10`

<img width="1389" alt="Screenshot 2023-09-04 at 12 36 08"
src="https://github.com/bevyengine/bevy/assets/302146/45fe8d6d-c901-4062-a349-3693dd044413">
This spawns the sprites selecting a texture at random per instance from
the 10 generated textures. This has no significant change vs main and
shouldn't.

### 2D Sprite `bevymark --benchmark --waves 160 --per-wave 1000 --mode
sprite --vary-per-instance`

<img width="1401" alt="Screenshot 2023-09-04 at 12 29 52"
src="https://github.com/bevyengine/bevy/assets/302146/762c5c60-352e-471f-8dbe-bbf10e24ebd6">
This sets the sprite colour as being unique per instance. This can still
all be drawn using one batch. There should be no difference but the PR
produces median frame times that are 4% higher. Investigation showed no
clear sources of cost, rather a mix of give and take that should not
happen. It seems like noise in the results.

### Summary

| Benchmark  | % change in median frame time |
| ------------- | ------------- |
| many_cubes  | 🟩 -30%  |
| many_cubes 10 materials  | 🟩 -5%  |
| many_cubes unique materials  | 🟩 ~0%  |
| bevymark mesh2d  | 🟩 -50%  |
| bevymark mesh2d 10 materials  | 🟩 -50%  |
| bevymark mesh2d unique materials  | 🟩 -7%  |
| bevymark sprite  | 🟥 2%  |
| bevymark sprite 10 materials  | 🟥 0.6%  |
| bevymark sprite unique materials  | 🟥 4.1%  |

---

## Changelog

- Added: 2D and 3D mesh entities that share the same mesh and material
(same textures, same data) are now batched into the same draw command
for better performance.

---------

Co-authored-by: robtfm <50659922+robtfm@users.noreply.github.com>
Co-authored-by: Nicola Papale <nico@nicopap.ch>
2023-09-21 22:12:34 +00:00