Commit Graph

28 Commits

Author SHA1 Message Date
Brian Reavis
03e299b455 Fix NonMesh draw command item queries (#17893)
# Objective

This fixes `NonMesh` draw commands not receiving render-world entities
since
- https://github.com/bevyengine/bevy/pull/17698

This unbreaks item queries for queued non-mesh entities:

```rust
struct MyDrawCommand {
    type ItemQuery = Read<DynamicUniformIndex<SomeUniform>>;
    // ...
}
```

### Solution

Pass render entity to `NonMesh` draw commands instead of
`Entity::PLACEHOLDER`. This PR also introduces sorting of the `NonMesh`
bin keys like other types, which I assume is the intended behavior.
@pcwalton

## Testing

- Tested on a local project that extensively uses `NonMesh` items.
2025-03-30 10:21:20 +02:00
Patrick Walton
8f36106f9e
Split out the IndirectParametersMetadata into CPU-populated and GPU-populated buffers. (#17863)
The GPU can fill out many of the fields in `IndirectParametersMetadata`
using information it already has:

* `early_instance_count` and `late_instance_count` are always
initialized to zero.

* `mesh_index` is already present in the work item buffer as the
`input_index` of the first work item in each batch.

This patch moves these fields to a separate buffer, the *GPU indirect
parameters metadata* buffer. That way, it avoids having to write them on
CPU during `batch_and_prepare_binned_render_phase`. This effectively
reduces the number of bits that that function must write per mesh from
160 to 64 (in addition to the 64 bits per mesh *instance*).

Additionally, this PR refactors `UntypedPhaseIndirectParametersBuffers`
to add another layer, `MeshClassIndirectParametersBuffers`, which allows
abstracting over the buffers corresponding indexed and non-indexed
meshes. This patch doesn't make much use of this abstraction, but
forthcoming patches will, and it's overall a cleaner approach.

This didn't seem to have much of an effect by itself on
`batch_and_prepare_binned_render_phase` time, but subsequent PRs
dependent on this PR yield roughly a 2× speedup.
2025-02-18 00:53:44 +00:00
Patrick Walton
0ede857103
Build batches across phases in parallel. (#17764)
Currently, invocations of `batch_and_prepare_binned_render_phase` and
`batch_and_prepare_sorted_render_phase` can't run in parallel because
they write to scene-global GPU buffers. After PR #17698,
`batch_and_prepare_binned_render_phase` started accounting for the
lion's share of the CPU time, causing us to be strongly CPU bound on
scenes like Caldera when occlusion culling was on (because of the
overhead of batching for the Z-prepass). Although I eventually plan to
optimize `batch_and_prepare_binned_render_phase`, we can obtain
significant wins now by parallelizing that system across phases.

This commit splits all GPU buffers that
`batch_and_prepare_binned_render_phase` and
`batch_and_prepare_sorted_render_phase` touches into separate buffers
for each phase so that the scheduler will run those phases in parallel.
At the end of batch preparation, we gather the render phases up into a
single resource with a new *collection* phase. Because we already run
mesh preprocessing separately for each phase in order to make occlusion
culling work, this is actually a cleaner separation. For example, mesh
output indices (the unique ID that identifies each mesh instance on GPU)
are now guaranteed to be sequential starting from 0, which will simplify
the forthcoming work to remove them in favor of the compute dispatch ID.

On Caldera, this brings the frame time down to approximately 9.1 ms with
occlusion culling on.

![Screenshot 2025-02-08
210720](https://github.com/user-attachments/assets/44bed500-e323-4786-b40c-828b75bc7d3f)
2025-02-13 00:02:20 +00:00
Patrick Walton
5ff7062c1c
Switch bins from parallel key/value arrays to IndexMaps. (#17819)
Conceptually, bins are ordered hash maps. We currently implement these
as a list of keys with an associated hash map. But we already have a
data type that implements ordered hash maps directly: `IndexMap`. This
patch switches Bevy to use `IndexMap`s for bins. Because we're memory
bound, this doesn't affect performance much, but it is cleaner.
2025-02-12 22:39:04 +00:00
Patrick Walton
85b366a8a2
Cache MeshInputUniform indices in each RenderBin. (#17772)
Currently, we look up each `MeshInputUniform` index in a hash table that
maps the main entity ID to the index every frame. This is inefficient,
cache unfriendly, and unnecessary, as the `MeshInputUniform` index for
an entity remains the same from frame to frame (even if the input
uniform changes). This commit changes the `IndexSet` in the `RenderBin`
to an `IndexMap` that maps the `MainEntity` to `MeshInputUniformIndex`
(a new type that this patch adds for more type safety).

On Caldera with parallel `batch_and_prepare_binned_render_phase`, this
patch improves that function from 3.18 ms to 2.42 ms, a 31% speedup.
2025-02-11 22:38:52 +00:00
Patrick Walton
7fc122ad16
Retain bins from frame to frame. (#17698)
This PR makes Bevy keep entities in bins from frame to frame if they
haven't changed. This reduces the time spent in `queue_material_meshes`
and related functions to near zero for static geometry. This patch uses
the same change tick technique that #17567 uses to detect when meshes
have changed in such a way as to require re-binning.

In order to quickly find the relevant bin for an entity when that entity
has changed, we introduce a new type of cache, the *bin key cache*. This
cache stores a mapping from main world entity ID to cached bin key, as
well as the tick of the most recent change to the entity. As we iterate
through the visible entities in `queue_material_meshes`, we check the
cache to see whether the entity needs to be re-binned. If it doesn't,
then we mark it as clean in the `valid_cached_entity_bin_keys` bit set.
If it does, then we insert it into the correct bin, and then mark the
entity as clean. At the end, all entities not marked as clean are
removed from the bins.

This patch has a dramatic effect on the rendering performance of most
benchmarks, as it effectively eliminates `queue_material_meshes` from
the profile. Note, however, that it generally simultaneously regresses
`batch_and_prepare_binned_render_phase` by a bit (not by enough to
outweigh the win, however). I believe that's because, before this patch,
`queue_material_meshes` put the bins in the CPU cache for
`batch_and_prepare_binned_render_phase` to use, while with this patch,
`batch_and_prepare_binned_render_phase` must load the bins into the CPU
cache itself.

On Caldera, this reduces the time spent in `queue_material_meshes` from
5+ ms to 0.2ms-0.3ms. Note that benchmarking on that scene is very noisy
right now because of https://github.com/bevyengine/bevy/issues/17535.

![Screenshot 2025-02-05
153458](https://github.com/user-attachments/assets/e55f8134-b7e3-4b78-a5af-8d83e1e213b7)
2025-02-08 20:13:33 +00:00
Patrick Walton
35101f3ed5
Use multi_draw_indirect_count where available, in preparation for two-phase occlusion culling. (#17211)
This commit allows Bevy to use `multi_draw_indirect_count` for drawing
meshes. The `multi_draw_indirect_count` feature works just like
`multi_draw_indirect`, but it takes the number of indirect parameters
from a GPU buffer rather than specifying it on the CPU.

Currently, the CPU constructs the list of indirect draw parameters with
the instance count for each batch set to zero, uploads the resulting
buffer to the GPU, and dispatches a compute shader that bumps the
instance count for each mesh that survives culling. Unfortunately, this
is inefficient when we support `multi_draw_indirect_count`. Draw
commands corresponding to meshes for which all instances were culled
will remain present in the list when calling
`multi_draw_indirect_count`, causing overhead. Proper use of
`multi_draw_indirect_count` requires eliminating these empty draw
commands.

To address this inefficiency, this PR makes Bevy fully construct the
indirect draw commands on the GPU instead of on the CPU. Instead of
writing instance counts to the draw command buffer, the mesh
preprocessing shader now writes them to a separate *indirect metadata
buffer*. A second compute dispatch known as the *build indirect
parameters* shader runs after mesh preprocessing and converts the
indirect draw metadata into actual indirect draw commands for the GPU.
The build indirect parameters shader operates on a batch at a time,
rather than an instance at a time, and as such each thread writes only 0
or 1 indirect draw parameters, simplifying the current logic in
`mesh_preprocessing`, which currently has to have special cases for the
first mesh in each batch. The build indirect parameters shader emits
draw commands in a tightly packed manner, enabling maximally efficient
use of `multi_draw_indirect_count`.

Along the way, this patch switches mesh preprocessing to dispatch one
compute invocation per render phase per view, instead of dispatching one
compute invocation per view. This is preparation for two-phase occlusion
culling, in which we will have two mesh preprocessing stages. In that
scenario, the first mesh preprocessing stage must only process opaque
and alpha tested objects, so the work items must be separated into those
that are opaque or alpha tested and those that aren't. Thus this PR
splits out the work items into a separate buffer for each phase. As this
patch rewrites so much of the mesh preprocessing infrastructure, it was
simpler to just fold the change into this patch instead of deferring it
to the forthcoming occlusion culling PR.

Finally, this patch changes mesh preprocessing so that it runs
separately for indexed and non-indexed meshes. This is because draw
commands for indexed and non-indexed meshes have different sizes and
layouts. *The existing code is actually broken for non-indexed meshes*,
as it attempts to overlay the indirect parameters for non-indexed meshes
on top of those for indexed meshes. Consequently, right now the
parameters will be read incorrectly when multiple non-indexed meshes are
multi-drawn together. *This is a bug fix* and, as with the change to
dispatch phases separately noted above, was easiest to include in this
patch as opposed to separately.

## Migration Guide

* Systems that add custom phase items now need to populate the indirect
drawing-related buffers. See the `specialized_mesh_pipeline` example for
an example of how this is done.
2025-01-14 21:19:20 +00:00
Patrick Walton
a8f15bd95e
Introduce two-level bins for multidrawable meshes. (#16898)
Currently, our batchable binned items are stored in a hash table that
maps bin key, which includes the batch set key, to a list of entities.
Multidraw is handled by sorting the bin keys and accumulating adjacent
bins that can be multidrawn together (i.e. have the same batch set key)
into multidraw commands during `batch_and_prepare_binned_render_phase`.

This is reasonably efficient right now, but it will complicate future
work to retain indirect draw parameters from frame to frame. Consider
what must happen when we have retained indirect draw parameters and the
application adds a bin (i.e. a new mesh) that shares a batch set key
with some pre-existing meshes. (That is, the new mesh can be multidrawn
with the pre-existing meshes.) To be maximally efficient, our goal in
that scenario will be to update *only* the indirect draw parameters for
the batch set (i.e. multidraw command) containing the mesh that was
added, while leaving the others alone. That means that we have to
quickly locate all the bins that belong to the batch set being modified.

In the existing code, we would have to sort the list of bin keys so that
bins that can be multidrawn together become adjacent to one another in
the list. Then we would have to do a binary search through the sorted
list to find the location of the bin that was just added. Next, we would
have to widen our search to adjacent indexes that contain the same batch
set, doing expensive comparisons against the batch set key every time.
Finally, we would reallocate the indirect draw parameters and update the
stored pointers to the indirect draw parameters that the bins store.

By contrast, it'd be dramatically simpler if we simply changed the way
bins are stored to first map from batch set key (i.e. multidraw command)
to the bins (i.e. meshes) within that batch set key, and then from each
individual bin to the mesh instances. That way, the scenario above in
which we add a new mesh will be simpler to handle. First, we will look
up the batch set key corresponding to that mesh in the outer map to find
an inner map corresponding to the single multidraw command that will
draw that batch set. We will know how many meshes the multidraw command
is going to draw by the size of that inner map. Then we simply need to
reallocate the indirect draw parameters and update the pointers to those
parameters within the bins as necessary. There will be no need to do any
binary search or expensive batch set key comparison: only a single hash
lookup and an iteration over the inner map to update the pointers.

This patch implements the above technique. Because we don't have
retained bins yet, this PR provides no performance benefits. However, it
opens the door to maximally efficient updates when only a small number
of meshes change from frame to frame.

The main churn that this patch causes is that the *batch set key* (which
uniquely specifies a multidraw command) and *bin key* (which uniquely
specifies a mesh *within* that multidraw command) are now separate,
instead of the batch set key being embedded *within* the bin key.

In order to isolate potential regressions, I think that at least #16890,
#16836, and #16825 should land before this PR does.

## Migration Guide

* The *batch set key* is now separate from the *bin key* in
`BinnedPhaseItem`. The batch set key is used to collect multidrawable
meshes together. If you aren't using the multidraw feature, you can
safely set the batch set key to `()`.
2025-01-06 18:34:40 +00:00
AlephCubed
cf6c65522f
Derived Default for all public unit components. (#17139)
Derived `Default` for all public unit structs that already derive from
`Component`. This allows them to be used more easily as required
components.
To avoid clutter in tests/examples, only public components were
affected, but this could easily be expanded to affect all unit
components.

Fixes #17052.
2025-01-05 02:45:09 +00:00
Patrick Walton
7767a8d161
Refactor batch_and_prepare_binned_render_phase in preparation for bin retention. (#16922)
This commit makes the following changes:

* `IndirectParametersBuffer` has been changed from a `BufferVec` to a
`RawBufferVec`. This won about 20us or so on Bistro by avoiding `encase`
overhead.

* The methods on the `GetFullBatchData` trait no longer have the
`entity` parameter, as it was unused.

* `PreprocessWorkItem`, which specifies a transform-and-cull operation,
now supplies the mesh instance uniform output index directly instead of
having the shader look it up from the indirect draw parameters.
Accordingly, the responsibility of writing the output index to the
indirect draw parameters has been moved from the CPU to the GPU. This is
in preparation for retained indirect instance draw commands, where the
mesh instance uniform output index may change from frame to frame, while
the indirect instance draw commands will be cached. We won't want the
CPU to have to upload the same indirect draw parameters again and again
if a batch didn't change from frame to frame.

* `batch_and_prepare_binned_render_phase` and
`batch_and_prepare_sorted_render_phase` now allocate indirect draw
commands for an entire batch set at a time when possible, instead of one
batch at a time. This change will allow us to retain the indirect draw
commands for whole batch sets.

* `GetFullBatchData::get_batch_indirect_parameters_index` has been
replaced with `GetFullBatchData::write_batch_indirect_parameters`, which
takes an offset and writes into it instead of allocating. This is
necessary in order to use the optimization mentioned in the previous
point.

* At the WGSL level, `IndirectParameters` has been factored out into
`mesh_preprocess_types.wgsl`. This is because we'll need a new compute
shader that zeroes out the instance counts in preparation for a new
frame. That shader will need to access `IndirectParameters`, so it was
moved to a separate file.

* Bins are no longer raw vectors but are instances of a separate type,
`RenderBin`. This is so that the bin can eventually contain its retained
batches.
2024-12-30 20:11:31 +00:00
Patrick Walton
1e7b89cdf5
Allow holes in the MeshInputUniform buffer. (#16695)
This commit removes the logic that attempted to keep the
`MeshInputUniform` buffer contiguous. Not only was it slow and complex,
but it was also incorrect, which caused #16686 and #16690. I changed the
logic to simply maintain a free list of unused slots in the buffer and
preferentially fill them when pushing new mesh input uniforms.

Closes #16686.
Closes #16690.
2024-12-09 02:11:27 +00:00
Patrick Walton
f5de3f08fb
Use multidraw for opaque meshes when GPU culling is in use. (#16427)
This commit adds support for *multidraw*, which is a feature that allows
multiple meshes to be drawn in a single drawcall. `wgpu` currently
implements multidraw on Vulkan, so this feature is only enabled there.
Multiple meshes can be drawn at once if they're in the same vertex and
index buffers and are otherwise placed in the same bin. (Thus, for
example, at present the materials and textures must be identical, but
see #16368.) Multidraw is a significant performance improvement during
the draw phase because it reduces the number of rebindings, as well as
the number of drawcalls.

This feature is currently only enabled when GPU culling is used: i.e.
when `GpuCulling` is present on a camera. Therefore, if you run for
example `scene_viewer`, you will not see any performance improvements,
because `scene_viewer` doesn't add the `GpuCulling` component to its
camera.

Additionally, the multidraw feature is only implemented for opaque 3D
meshes and not for shadows or 2D meshes. I plan to make GPU culling the
default and to extend the feature to shadows in the future. Also, in the
future I suspect that polyfilling multidraw on APIs that don't support
it will be fruitful, as even without driver-level support use of
multidraw allows us to avoid expensive `wgpu` rebindings.
2024-12-06 17:22:03 +00:00
charlotte
dd812b3e49
Type safe retained render world (#15756)
# Objective

In the Render World, there are a number of collections that are derived
from Main World entities and are used to drive rendering. The most
notable are:
- `VisibleEntities`, which is generated in the `check_visibility` system
and contains visible entities for a view.
- `ExtractedInstances`, which maps entity ids to asset ids.

In the old model, these collections were trivially kept in sync -- any
extracted phase item could look itself up because the render entity id
was guaranteed to always match the corresponding main world id.

After #15320, this became much more complicated, and was leading to a
number of subtle bugs in the Render World. The main rendering systems,
i.e. `queue_material_meshes` and `queue_material2d_meshes`, follow a
similar pattern:

```rust
for visible_entity in visible_entities.iter::<With<Mesh2d>>() {
    let Some(mesh_instance) = render_mesh_instances.get_mut(visible_entity) else {
        continue;
    };
            
    // Look some more stuff up and specialize the pipeline...
            
    let bin_key = Opaque2dBinKey {
        pipeline: pipeline_id,
        draw_function: draw_opaque_2d,
        asset_id: mesh_instance.mesh_asset_id.into(),
        material_bind_group_id: material_2d.get_bind_group_id().0,
    };
    opaque_phase.add(
        bin_key,
        *visible_entity,
        BinnedRenderPhaseType::mesh(mesh_instance.automatic_batching),
    );
}
```

In this case, `visible_entities` and `render_mesh_instances` are both
collections that are created and keyed by Main World entity ids, and so
this lookup happens to work by coincidence. However, there is a major
unintentional bug here: namely, because `visible_entities` is a
collection of Main World ids, the phase item being queued is created
with a Main World id rather than its correct Render World id.

This happens to not break mesh rendering because the render commands
used for drawing meshes do not access the `ItemQuery` parameter, but
demonstrates the confusion that is now possible: our UI phase items are
correctly being queued with Render World ids while our meshes aren't.

Additionally, this makes it very easy and error prone to use the wrong
entity id to look up things like assets. For example, if instead we
ignored visibility checks and queued our meshes via a query, we'd have
to be extra careful to use `&MainEntity` instead of the natural
`Entity`.

## Solution

Make all collections that are derived from Main World data use
`MainEntity` as their key, to ensure type safety and avoid accidentally
looking up data with the wrong entity id:

```rust
pub type MainEntityHashMap<V> = hashbrown::HashMap<MainEntity, V, EntityHash>;
```

Additionally, we make all `PhaseItem` be able to provide both their Main
and Render World ids, to allow render phase implementors maximum
flexibility as to what id should be used to look up data.

You can think of this like tracking at the type level whether something
in the Render World should use it's "primary key", i.e. entity id, or
needs to use a foreign key, i.e. `MainEntity`.

## Testing

##### TODO:

This will require extensive testing to make sure things didn't break!
Additionally, some extraction logic has become more complicated and
needs to be checked for regressions.

## Migration Guide

With the advent of the retained render world, collections that contain
references to `Entity` that are extracted into the render world have
been changed to contain `MainEntity` in order to prevent errors where a
render world entity id is used to look up an item by accident. Custom
rendering code may need to be changed to query for `&MainEntity` in
order to look up the correct item from such a collection. Additionally,
users who implement their own extraction logic for collections of main
world entity should strongly consider extracting into a different
collection that uses `MainEntity` as a key.

Additionally, render phases now require specifying both the `Entity` and
`MainEntity` for a given `PhaseItem`. Custom render phases should ensure
`MainEntity` is available when queuing a phase item.
2024-10-10 18:47:04 +00:00
Patrick Walton
44db8b7fac
Allow phase items not associated with meshes to be binned. (#14029)
As reported in #14004, many third-party plugins, such as Hanabi, enqueue
entities that don't have meshes into render phases. However, the
introduction of indirect mode added a dependency on mesh-specific data,
breaking this workflow. This is because GPU preprocessing requires that
the render phases manage indirect draw parameters, which don't apply to
objects that aren't meshes. The existing code skips over binned entities
that don't have indirect draw parameters, which causes the rendering to
be skipped for such objects.

To support this workflow, this commit adds a new field,
`non_mesh_items`, to `BinnedRenderPhase`. This field contains a simple
list of (bin key, entity) pairs. After drawing batchable and unbatchable
objects, the non-mesh items are drawn one after another. Bevy itself
doesn't enqueue any items into this list; it exists solely for the
application and/or plugins to use.

Additionally, this commit switches the asset ID in the standard bin keys
to be an untyped asset ID rather than that of a mesh. This allows more
flexibility, allowing bins to be keyed off any type of asset.

This patch adds a new example, `custom_phase_item`, which simultaneously
serves to demonstrate how to use this new feature and to act as a
regression test so this doesn't break again.

Fixes #14004.

## Changelog

### Added

* `BinnedRenderPhase` now contains a `non_mesh_items` field for plugins
to add custom items to.
2024-06-27 16:13:03 +00:00
Patrick Walton
9da0b2a0ec
Make render phases render world resources instead of components. (#13277)
This commit makes us stop using the render world ECS for
`BinnedRenderPhase` and `SortedRenderPhase` and instead use resources
with `EntityHashMap`s inside. There are three reasons to do this:

1. We can use `clear()` to clear out the render phase collections
instead of recreating the components from scratch, allowing us to reuse
allocations.

2. This is a prerequisite for retained bins, because components can't be
retained from frame to frame in the render world, but resources can.

3. We want to move away from storing anything in components in the
render world ECS, and this is a step in that direction.

This patch results in a small performance benefit, due to point (1)
above.

## Changelog

### Changed

* The `BinnedRenderPhase` and `SortedRenderPhase` render world
components have been replaced with `ViewBinnedRenderPhases` and
`ViewSortedRenderPhases` resources.

## Migration Guide

* The `BinnedRenderPhase` and `SortedRenderPhase` render world
components have been replaced with `ViewBinnedRenderPhases` and
`ViewSortedRenderPhases` resources. Instead of querying for the
components, look the camera entity up in the
`ViewBinnedRenderPhases`/`ViewSortedRenderPhases` tables.
2024-05-21 18:23:04 +00:00
Patrick Walton
16531fb3e3
Implement GPU frustum culling. (#12889)
This commit implements opt-in GPU frustum culling, built on top of the
infrastructure in https://github.com/bevyengine/bevy/pull/12773. To
enable it on a camera, add the `GpuCulling` component to it. To
additionally disable CPU frustum culling, add the `NoCpuCulling`
component. Note that adding `GpuCulling` without `NoCpuCulling`
*currently* does nothing useful. The reason why `GpuCulling` doesn't
automatically imply `NoCpuCulling` is that I intend to follow this patch
up with GPU two-phase occlusion culling, and CPU frustum culling plus
GPU occlusion culling seems like a very commonly-desired mode.

Adding the `GpuCulling` component to a view puts that view into
*indirect mode*. This mode makes all drawcalls indirect, relying on the
mesh preprocessing shader to allocate instances dynamically. In indirect
mode, the `PreprocessWorkItem` `output_index` points not to a
`MeshUniform` instance slot but instead to a set of `wgpu`
`IndirectParameters`, from which it allocates an instance slot
dynamically if frustum culling succeeds. Batch building has been updated
to allocate and track indirect parameter slots, and the AABBs are now
supplied to the GPU as `MeshCullingData`.

A small amount of code relating to the frustum culling has been borrowed
from meshlets and moved into `maths.wgsl`. Note that standard Bevy
frustum culling uses AABBs, while meshlets use bounding spheres; this
means that not as much code can be shared as one might think.

This patch doesn't provide any way to perform GPU culling on shadow
maps, to avoid making this patch bigger than it already is. That can be
a followup.

## Changelog

### Added

* Frustum culling can now optionally be done on the GPU. To enable it,
add the `GpuCulling` component to a camera.
* To disable CPU frustum culling, add `NoCpuCulling` to a camera. Note
that `GpuCulling` doesn't automatically imply `NoCpuCulling`.
2024-04-28 12:50:00 +00:00
BD103
7b8d502083
Fix beta lints (#12980)
# Objective

- Fixes #12976

## Solution

This one is a doozy.

- Run `cargo +beta clippy --workspace --all-targets --all-features` and
fix all issues
- This includes:
- Moving inner attributes to be outer attributes, when the item in
question has both inner and outer attributes
  - Use `ptr::from_ref` in more scenarios
- Extend the valid idents list used by `clippy:doc_markdown` with more
names
  - Use `Clone::clone_from` when possible
  - Remove redundant `ron` import
  - Add backticks to **so many** identifiers and items
    - I'm sorry whoever has to review this

---

## Changelog

- Added links to more identifiers in documentation.
2024-04-16 02:46:46 +00:00
Robert Swain
5f05e75a70
Fix 2D BatchedInstanceBuffer clear (#12922)
# Objective

- `cargo run --release --example bevymark -- --benchmark --waves 160
--per-wave 1000 --mode mesh2d` runs slower and slower over time due to
`no_gpu_preprocessing::write_batched_instance_buffer<bevy_sprite::mesh2d::mesh::Mesh2dPipeline>`
taking longer and longer because the `BatchedInstanceBuffer` is not
cleared

## Solution

- Split the `clear_batched_instance_buffers` system into CPU and GPU
versions
- Use the CPU version for 2D meshes
2024-04-15 05:00:43 +00:00
Patrick Walton
11817f4ba4
Generate MeshUniforms on the GPU via compute shader where available. (#12773)
Currently, `MeshUniform`s are rather large: 160 bytes. They're also
somewhat expensive to compute, because they involve taking the inverse
of a 3x4 matrix. Finally, if a mesh is present in multiple views, that
mesh will have a separate `MeshUniform` for each and every view, which
is wasteful.

This commit fixes these issues by introducing the concept of a *mesh
input uniform* and adding a *mesh uniform building* compute shader pass.
The `MeshInputUniform` is simply the minimum amount of data needed for
the GPU to compute the full `MeshUniform`. Most of this data is just the
transform and is therefore only 64 bytes. `MeshInputUniform`s are
computed during the *extraction* phase, much like skins are today, in
order to avoid needlessly copying transforms around on CPU. (In fact,
the render app has been changed to only store the translation of each
mesh; it no longer cares about any other part of the transform, which is
stored only on the GPU and the main world.) Before rendering, the
`build_mesh_uniforms` pass runs to expand the `MeshInputUniform`s to the
full `MeshUniform`.

The mesh uniform building pass does the following, all on GPU:

1. Copy the appropriate fields of the `MeshInputUniform` to the
`MeshUniform` slot. If a single mesh is present in multiple views, this
effectively duplicates it into each view.

2. Compute the inverse transpose of the model transform, used for
transforming normals.

3. If applicable, copy the mesh's transform from the previous frame for
TAA. To support this, we double-buffer the `MeshInputUniform`s over two
frames and swap the buffers each frame. The `MeshInputUniform`s for the
current frame contain the index of that mesh's `MeshInputUniform` for
the previous frame.

This commit produces wins in virtually every CPU part of the pipeline:
`extract_meshes`, `queue_material_meshes`,
`batch_and_prepare_render_phase`, and especially
`write_batched_instance_buffer` are all faster. Shrinking the amount of
CPU data that has to be shuffled around speeds up the entire rendering
process.

| Benchmark              | This branch | `main`  | Speedup |
|------------------------|-------------|---------|---------|
| `many_cubes -nfc`      |      17.259 |  24.529 |  42.12% |
| `many_cubes -nfc -vpi` |     302.116 | 312.123 |   3.31% |
| `many_foxes`           |       3.227 |   3.515 |   8.92% |

Because mesh uniform building requires compute shader, and WebGL 2 has
no compute shader, the existing CPU mesh uniform building code has been
left as-is. Many types now have both CPU mesh uniform building and GPU
mesh uniform building modes. Developers can opt into the old CPU mesh
uniform building by setting the `use_gpu_uniform_builder` option on
`PbrPlugin` to `false`.

Below are graphs of the CPU portions of `many-cubes
--no-frustum-culling`. Yellow is this branch, red is `main`.

`extract_meshes`:
![Screenshot 2024-04-02
124842](https://github.com/bevyengine/bevy/assets/157897/a6748ea4-dd05-47b6-9254-45d07d33cb10)
It's notable that we get a small win even though we're now writing to a
GPU buffer.

`queue_material_meshes`:
![Screenshot 2024-04-02
124911](https://github.com/bevyengine/bevy/assets/157897/ecb44d78-65dc-448d-ba85-2de91aa2ad94)
There's a bit of a regression here; not sure what's causing it. In any
case it's very outweighed by the other gains.

`batch_and_prepare_render_phase`:
![Screenshot 2024-04-02
125123](https://github.com/bevyengine/bevy/assets/157897/4e20fc86-f9dd-4e5c-8623-837e4258f435)
There's a huge win here, enough to make batching basically drop off the
profile.

`write_batched_instance_buffer`:
![Screenshot 2024-04-02
125237](https://github.com/bevyengine/bevy/assets/157897/401a5c32-9dc1-4991-996d-eb1cac6014b2)
There's a massive improvement here, as expected. Note that a lot of it
simply comes from the fact that `MeshInputUniform` is `Pod`. (This isn't
a maintainability problem in my view because `MeshInputUniform` is so
simple: just 16 tightly-packed words.)

## Changelog

### Added

* Per-mesh instance data is now generated on GPU with a compute shader
instead of CPU, resulting in rendering performance improvements on
platforms where compute shaders are supported.

## Migration guide

* Custom render phases now need multiple systems beyond just
`batch_and_prepare_render_phase`. Code that was previously creating
custom render phases should now add a `BinnedRenderPhasePlugin` or
`SortedRenderPhasePlugin` as appropriate instead of directly adding
`batch_and_prepare_render_phase`.
2024-04-10 05:33:32 +00:00
Patrick Walton
4dadebd9c4
Improve performance by binning together opaque items instead of sorting them. (#12453)
Today, we sort all entities added to all phases, even the phases that
don't strictly need sorting, such as the opaque and shadow phases. This
results in a performance loss because our `PhaseItem`s are rather large
in memory, so sorting is slow. Additionally, determining the boundaries
of batches is an O(n) process.

This commit makes Bevy instead applicable place phase items into *bins*
keyed by *bin keys*, which have the invariant that everything in the
same bin is potentially batchable. This makes determining batch
boundaries O(1), because everything in the same bin can be batched.
Instead of sorting each entity, we now sort only the bin keys. This
drops the sorting time to near-zero on workloads with few bins like
`many_cubes --no-frustum-culling`. Memory usage is improved too, with
batch boundaries and dynamic indices now implicit instead of explicit.
The improved memory usage results in a significant win even on
unbatchable workloads like `many_cubes --no-frustum-culling
--vary-material-data-per-instance`, presumably due to cache effects.

Not all phases can be binned; some, such as transparent and transmissive
phases, must still be sorted. To handle this, this commit splits
`PhaseItem` into `BinnedPhaseItem` and `SortedPhaseItem`. Most of the
logic that today deals with `PhaseItem`s has been moved to
`SortedPhaseItem`. `BinnedPhaseItem` has the new logic.

Frame time results (in ms/frame) are as follows:

| Benchmark                | `binning` | `main`  | Speedup |
| ------------------------ | --------- | ------- | ------- |
| `many_cubes -nfc -vpi` | 232.179     | 312.123   | 34.43%  |
| `many_cubes -nfc`        | 25.874 | 30.117 | 16.40%  |
| `many_foxes`             | 3.276 | 3.515 | 7.30%   |

(`-nfc` is short for `--no-frustum-culling`; `-vpi` is short for
`--vary-per-instance`.)

---

## Changelog

### Changed

* Render phases have been split into binned and sorted phases. Binned
phases, such as the common opaque phase, achieve improved CPU
performance by avoiding the sorting step.

## Migration Guide

- `PhaseItem` has been split into `BinnedPhaseItem` and
`SortedPhaseItem`. If your code has custom `PhaseItem`s, you will need
to migrate them to one of these two types. `SortedPhaseItem` requires
the fewest code changes, but you may want to pick `BinnedPhaseItem` if
your phase doesn't require sorting, as that enables higher performance.

## Tracy graphs

`many-cubes --no-frustum-culling`, `main` branch:
<img width="1064" alt="Screenshot 2024-03-12 180037"
src="https://github.com/bevyengine/bevy/assets/157897/e1180ce8-8e89-46d2-85e3-f59f72109a55">

`many-cubes --no-frustum-culling`, this branch:
<img width="1064" alt="Screenshot 2024-03-12 180011"
src="https://github.com/bevyengine/bevy/assets/157897/0899f036-6075-44c5-a972-44d95895f46c">

You can see that `batch_and_prepare_binned_render_phase` is a much
smaller fraction of the time. Zooming in on that function, with yellow
being this branch and red being `main`, we see:

<img width="1064" alt="Screenshot 2024-03-12 175832"
src="https://github.com/bevyengine/bevy/assets/157897/0dfc8d3f-49f4-496e-8825-a66e64d356d0">

The binning happens in `queue_material_meshes`. Again with yellow being
this branch and red being `main`:
<img width="1064" alt="Screenshot 2024-03-12 175755"
src="https://github.com/bevyengine/bevy/assets/157897/b9b20dc1-11c8-400c-a6cc-1c2e09c1bb96">

We can see that there is a small regression in `queue_material_meshes`
performance, but it's not nearly enough to outweigh the large gains in
`batch_and_prepare_binned_render_phase`.

---------

Co-authored-by: James Liu <contact@jamessliu.com>
2024-03-30 02:55:02 +00:00
James Liu
512b7463a3
Disentangle bevy_utils/bevy_core's reexported dependencies (#12313)
# Objective
Make bevy_utils less of a compilation bottleneck. Tackle #11478.

## Solution
* Move all of the directly reexported dependencies and move them to
where they're actually used.
* Remove the UUID utilities that have gone unused since `TypePath` took
over for `TypeUuid`.
* There was also a extraneous bytemuck dependency on `bevy_core` that
has not been used for a long time (since `encase` became the primary way
to prepare GPU buffers).
* Remove the `all_tuples` macro reexport from bevy_ecs since it's
accessible from `bevy_utils`.

---

## Changelog
Removed: Many of the reexports from bevy_utils (petgraph, uuid, nonmax,
smallvec, and thiserror).
Removed: bevy_core's reexports of bytemuck.

## Migration Guide
bevy_utils' reexports of petgraph, uuid, nonmax, smallvec, and thiserror
have been removed.

bevy_core' reexports of bytemuck's types has been removed. 

Add them as dependencies in your own crate instead.
2024-03-07 02:30:15 +00:00
James Liu
eb52a489ad
Batching: replace GpuArrayBufferIndex::index with a u32 (#12250)
# Objective
While mucking around with batch_and_prepare systems, it became apparent
that `GpuArrayBufferIndex::index` doesn't need to be a NonMaxU32.

## Solution
Replace it with a normal u32. 

This likely has some potential perf benefit by avoiding panics and the
NOT operations, but I haven't been able to find any substantial gains,
so this is primarily for code quality.

---

## Changelog
Changed: `GpuArrayBufferIndex::index` is now a u32.

## Migration Guide
`GpuArrayBuferIndex::index` is now a u32 instead of a `NonMaxU32`.
Remove any calls to `NonMaxU32::get` on the member.
2024-03-02 16:00:28 +00:00
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