bevy/crates/bevy_pbr/src/prepass/mod.rs
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

963 lines
35 KiB
Rust

mod prepass_bindings;
use bevy_render::mesh::{GpuMesh, MeshVertexBufferLayoutRef};
use bevy_render::render_resource::binding_types::uniform_buffer;
pub use prepass_bindings::*;
use bevy_asset::{load_internal_asset, AssetServer};
use bevy_core_pipeline::{core_3d::CORE_3D_DEPTH_FORMAT, prelude::Camera3d};
use bevy_core_pipeline::{deferred::*, prepass::*};
use bevy_ecs::{
prelude::*,
system::{
lifetimeless::{Read, SRes},
SystemParamItem,
},
};
use bevy_math::{Affine3A, Mat4};
use bevy_render::{
globals::{GlobalsBuffer, GlobalsUniform},
prelude::{Camera, Mesh},
render_asset::RenderAssets,
render_phase::*,
render_resource::*,
renderer::{RenderDevice, RenderQueue},
view::{ExtractedView, Msaa, ViewUniform, ViewUniformOffset, ViewUniforms, VisibleEntities},
Extract,
};
use bevy_transform::prelude::GlobalTransform;
use bevy_utils::tracing::error;
#[cfg(feature = "meshlet")]
use crate::meshlet::{
prepare_material_meshlet_meshes_prepass, queue_material_meshlet_meshes, MeshletGpuScene,
};
use crate::*;
use std::{hash::Hash, marker::PhantomData};
pub const PREPASS_SHADER_HANDLE: Handle<Shader> = Handle::weak_from_u128(921124473254008983);
pub const PREPASS_BINDINGS_SHADER_HANDLE: Handle<Shader> =
Handle::weak_from_u128(5533152893177403494);
pub const PREPASS_UTILS_SHADER_HANDLE: Handle<Shader> = Handle::weak_from_u128(4603948296044544);
pub const PREPASS_IO_SHADER_HANDLE: Handle<Shader> = Handle::weak_from_u128(81212356509530944);
/// Sets up everything required to use the prepass pipeline.
///
/// This does not add the actual prepasses, see [`PrepassPlugin`] for that.
pub struct PrepassPipelinePlugin<M: Material>(PhantomData<M>);
impl<M: Material> Default for PrepassPipelinePlugin<M> {
fn default() -> Self {
Self(Default::default())
}
}
impl<M: Material> Plugin for PrepassPipelinePlugin<M>
where
M::Data: PartialEq + Eq + Hash + Clone,
{
fn build(&self, app: &mut App) {
load_internal_asset!(
app,
PREPASS_SHADER_HANDLE,
"prepass.wgsl",
Shader::from_wgsl
);
load_internal_asset!(
app,
PREPASS_BINDINGS_SHADER_HANDLE,
"prepass_bindings.wgsl",
Shader::from_wgsl
);
load_internal_asset!(
app,
PREPASS_UTILS_SHADER_HANDLE,
"prepass_utils.wgsl",
Shader::from_wgsl
);
load_internal_asset!(
app,
PREPASS_IO_SHADER_HANDLE,
"prepass_io.wgsl",
Shader::from_wgsl
);
let Some(render_app) = app.get_sub_app_mut(RenderApp) else {
return;
};
render_app
.add_systems(
Render,
prepare_prepass_view_bind_group::<M>.in_set(RenderSet::PrepareBindGroups),
)
.init_resource::<PrepassViewBindGroup>()
.init_resource::<SpecializedMeshPipelines<PrepassPipeline<M>>>()
.allow_ambiguous_resource::<SpecializedMeshPipelines<PrepassPipeline<M>>>()
.init_resource::<PreviousViewProjectionUniforms>();
}
fn finish(&self, app: &mut App) {
let Some(render_app) = app.get_sub_app_mut(RenderApp) else {
return;
};
render_app.init_resource::<PrepassPipeline<M>>();
}
}
/// Sets up the prepasses for a [`Material`].
///
/// This depends on the [`PrepassPipelinePlugin`].
pub struct PrepassPlugin<M: Material>(PhantomData<M>);
impl<M: Material> Default for PrepassPlugin<M> {
fn default() -> Self {
Self(Default::default())
}
}
impl<M: Material> Plugin for PrepassPlugin<M>
where
M::Data: PartialEq + Eq + Hash + Clone,
{
fn build(&self, app: &mut App) {
let no_prepass_plugin_loaded = app
.world()
.get_resource::<AnyPrepassPluginLoaded>()
.is_none();
if no_prepass_plugin_loaded {
app.insert_resource(AnyPrepassPluginLoaded)
// At the start of each frame, last frame's GlobalTransforms become this frame's PreviousGlobalTransforms
// and last frame's view projection matrices become this frame's PreviousViewProjections
.add_systems(
PreUpdate,
(
update_mesh_previous_global_transforms,
update_previous_view_data,
),
)
.add_plugins((
BinnedRenderPhasePlugin::<Opaque3dPrepass, MeshPipeline>::default(),
BinnedRenderPhasePlugin::<AlphaMask3dPrepass, MeshPipeline>::default(),
));
}
let Some(render_app) = app.get_sub_app_mut(RenderApp) else {
return;
};
if no_prepass_plugin_loaded {
render_app
.add_systems(ExtractSchedule, extract_camera_previous_view_data)
.add_systems(
Render,
prepare_previous_view_uniforms.in_set(RenderSet::PrepareResources),
);
}
render_app
.add_render_command::<Opaque3dPrepass, DrawPrepass<M>>()
.add_render_command::<AlphaMask3dPrepass, DrawPrepass<M>>()
.add_render_command::<Opaque3dDeferred, DrawPrepass<M>>()
.add_render_command::<AlphaMask3dDeferred, DrawPrepass<M>>()
.add_systems(
Render,
queue_prepass_material_meshes::<M>
.in_set(RenderSet::QueueMeshes)
.after(prepare_assets::<PreparedMaterial<M>>)
// queue_material_meshes only writes to `material_bind_group_id`, which `queue_prepass_material_meshes` doesn't read
.ambiguous_with(queue_material_meshes::<StandardMaterial>),
);
#[cfg(feature = "meshlet")]
render_app.add_systems(
Render,
prepare_material_meshlet_meshes_prepass::<M>
.in_set(RenderSet::Queue)
.before(queue_material_meshlet_meshes::<M>)
.run_if(resource_exists::<MeshletGpuScene>),
);
}
}
#[derive(Resource)]
struct AnyPrepassPluginLoaded;
#[derive(Component, ShaderType, Clone)]
pub struct PreviousViewData {
pub inverse_view: Mat4,
pub view_proj: Mat4,
}
pub fn update_previous_view_data(
mut commands: Commands,
query: Query<(Entity, &Camera, &GlobalTransform), (With<Camera3d>, With<MotionVectorPrepass>)>,
) {
for (entity, camera, camera_transform) in &query {
let inverse_view = camera_transform.compute_matrix().inverse();
commands.entity(entity).try_insert(PreviousViewData {
inverse_view,
view_proj: camera.projection_matrix() * inverse_view,
});
}
}
#[derive(Component)]
pub struct PreviousGlobalTransform(pub Affine3A);
pub fn update_mesh_previous_global_transforms(
mut commands: Commands,
views: Query<&Camera, (With<Camera3d>, With<MotionVectorPrepass>)>,
meshes: Query<(Entity, &GlobalTransform), With<Handle<Mesh>>>,
) {
let should_run = views.iter().any(|camera| camera.is_active);
if should_run {
for (entity, transform) in &meshes {
commands
.entity(entity)
.try_insert(PreviousGlobalTransform(transform.affine()));
}
}
}
#[derive(Resource)]
pub struct PrepassPipeline<M: Material> {
pub view_layout_motion_vectors: BindGroupLayout,
pub view_layout_no_motion_vectors: BindGroupLayout,
pub mesh_layouts: MeshLayouts,
pub material_layout: BindGroupLayout,
pub prepass_material_vertex_shader: Option<Handle<Shader>>,
pub prepass_material_fragment_shader: Option<Handle<Shader>>,
pub deferred_material_vertex_shader: Option<Handle<Shader>>,
pub deferred_material_fragment_shader: Option<Handle<Shader>>,
pub material_pipeline: MaterialPipeline<M>,
_marker: PhantomData<M>,
}
impl<M: Material> FromWorld for PrepassPipeline<M> {
fn from_world(world: &mut World) -> Self {
let render_device = world.resource::<RenderDevice>();
let asset_server = world.resource::<AssetServer>();
let view_layout_motion_vectors = render_device.create_bind_group_layout(
"prepass_view_layout_motion_vectors",
&BindGroupLayoutEntries::sequential(
ShaderStages::VERTEX_FRAGMENT,
(
// View
uniform_buffer::<ViewUniform>(true),
// Globals
uniform_buffer::<GlobalsUniform>(false),
// PreviousViewUniforms
uniform_buffer::<PreviousViewData>(true),
),
),
);
let view_layout_no_motion_vectors = render_device.create_bind_group_layout(
"prepass_view_layout_no_motion_vectors",
&BindGroupLayoutEntries::sequential(
ShaderStages::VERTEX_FRAGMENT,
(
// View
uniform_buffer::<ViewUniform>(true),
// Globals
uniform_buffer::<GlobalsUniform>(false),
),
),
);
let mesh_pipeline = world.resource::<MeshPipeline>();
PrepassPipeline {
view_layout_motion_vectors,
view_layout_no_motion_vectors,
mesh_layouts: mesh_pipeline.mesh_layouts.clone(),
prepass_material_vertex_shader: match M::prepass_vertex_shader() {
ShaderRef::Default => None,
ShaderRef::Handle(handle) => Some(handle),
ShaderRef::Path(path) => Some(asset_server.load(path)),
},
prepass_material_fragment_shader: match M::prepass_fragment_shader() {
ShaderRef::Default => None,
ShaderRef::Handle(handle) => Some(handle),
ShaderRef::Path(path) => Some(asset_server.load(path)),
},
deferred_material_vertex_shader: match M::deferred_vertex_shader() {
ShaderRef::Default => None,
ShaderRef::Handle(handle) => Some(handle),
ShaderRef::Path(path) => Some(asset_server.load(path)),
},
deferred_material_fragment_shader: match M::deferred_fragment_shader() {
ShaderRef::Default => None,
ShaderRef::Handle(handle) => Some(handle),
ShaderRef::Path(path) => Some(asset_server.load(path)),
},
material_layout: M::bind_group_layout(render_device),
material_pipeline: world.resource::<MaterialPipeline<M>>().clone(),
_marker: PhantomData,
}
}
}
impl<M: Material> SpecializedMeshPipeline for PrepassPipeline<M>
where
M::Data: PartialEq + Eq + Hash + Clone,
{
type Key = MaterialPipelineKey<M>;
fn specialize(
&self,
key: Self::Key,
layout: &MeshVertexBufferLayoutRef,
) -> Result<RenderPipelineDescriptor, SpecializedMeshPipelineError> {
let mut bind_group_layouts = vec![if key
.mesh_key
.contains(MeshPipelineKey::MOTION_VECTOR_PREPASS)
{
self.view_layout_motion_vectors.clone()
} else {
self.view_layout_no_motion_vectors.clone()
}];
let mut shader_defs = Vec::new();
let mut vertex_attributes = Vec::new();
// Let the shader code know that it's running in a prepass pipeline.
// (PBR code will use this to detect that it's running in deferred mode,
// since that's the only time it gets called from a prepass pipeline.)
shader_defs.push("PREPASS_PIPELINE".into());
// NOTE: Eventually, it would be nice to only add this when the shaders are overloaded by the Material.
// The main limitation right now is that bind group order is hardcoded in shaders.
bind_group_layouts.push(self.material_layout.clone());
#[cfg(all(feature = "webgl", target_arch = "wasm32", not(feature = "webgpu")))]
shader_defs.push("WEBGL2".into());
shader_defs.push("VERTEX_OUTPUT_INSTANCE_INDEX".into());
if key.mesh_key.contains(MeshPipelineKey::DEPTH_PREPASS) {
shader_defs.push("DEPTH_PREPASS".into());
}
if key.mesh_key.contains(MeshPipelineKey::MAY_DISCARD) {
shader_defs.push("MAY_DISCARD".into());
}
let blend_key = key
.mesh_key
.intersection(MeshPipelineKey::BLEND_RESERVED_BITS);
if blend_key == MeshPipelineKey::BLEND_PREMULTIPLIED_ALPHA {
shader_defs.push("BLEND_PREMULTIPLIED_ALPHA".into());
}
if blend_key == MeshPipelineKey::BLEND_ALPHA {
shader_defs.push("BLEND_ALPHA".into());
}
if layout.0.contains(Mesh::ATTRIBUTE_POSITION) {
shader_defs.push("VERTEX_POSITIONS".into());
vertex_attributes.push(Mesh::ATTRIBUTE_POSITION.at_shader_location(0));
}
if key.mesh_key.contains(MeshPipelineKey::DEPTH_CLAMP_ORTHO) {
shader_defs.push("DEPTH_CLAMP_ORTHO".into());
// PERF: This line forces the "prepass fragment shader" to always run in
// common scenarios like "directional light calculation". Doing so resolves
// a pretty nasty depth clamping bug, but it also feels a bit excessive.
// We should try to find a way to resolve this without forcing the fragment
// shader to run.
// https://github.com/bevyengine/bevy/pull/8877
shader_defs.push("PREPASS_FRAGMENT".into());
}
if layout.0.contains(Mesh::ATTRIBUTE_UV_0) {
shader_defs.push("VERTEX_UVS".into());
vertex_attributes.push(Mesh::ATTRIBUTE_UV_0.at_shader_location(1));
}
if layout.0.contains(Mesh::ATTRIBUTE_UV_1) {
shader_defs.push("VERTEX_UVS_B".into());
vertex_attributes.push(Mesh::ATTRIBUTE_UV_1.at_shader_location(2));
}
if key.mesh_key.contains(MeshPipelineKey::NORMAL_PREPASS) {
shader_defs.push("NORMAL_PREPASS".into());
}
if key
.mesh_key
.intersects(MeshPipelineKey::NORMAL_PREPASS | MeshPipelineKey::DEFERRED_PREPASS)
{
vertex_attributes.push(Mesh::ATTRIBUTE_NORMAL.at_shader_location(3));
shader_defs.push("NORMAL_PREPASS_OR_DEFERRED_PREPASS".into());
if layout.0.contains(Mesh::ATTRIBUTE_TANGENT) {
shader_defs.push("VERTEX_TANGENTS".into());
vertex_attributes.push(Mesh::ATTRIBUTE_TANGENT.at_shader_location(4));
}
}
if key
.mesh_key
.intersects(MeshPipelineKey::MOTION_VECTOR_PREPASS | MeshPipelineKey::DEFERRED_PREPASS)
{
shader_defs.push("MOTION_VECTOR_PREPASS_OR_DEFERRED_PREPASS".into());
}
if key.mesh_key.contains(MeshPipelineKey::DEFERRED_PREPASS) {
shader_defs.push("DEFERRED_PREPASS".into());
}
if layout.0.contains(Mesh::ATTRIBUTE_COLOR) {
shader_defs.push("VERTEX_COLORS".into());
vertex_attributes.push(Mesh::ATTRIBUTE_COLOR.at_shader_location(7));
}
if key
.mesh_key
.contains(MeshPipelineKey::MOTION_VECTOR_PREPASS)
{
shader_defs.push("MOTION_VECTOR_PREPASS".into());
}
if key.mesh_key.intersects(
MeshPipelineKey::NORMAL_PREPASS
| MeshPipelineKey::MOTION_VECTOR_PREPASS
| MeshPipelineKey::DEFERRED_PREPASS,
) {
shader_defs.push("PREPASS_FRAGMENT".into());
}
let bind_group = setup_morph_and_skinning_defs(
&self.mesh_layouts,
layout,
5,
&key.mesh_key,
&mut shader_defs,
&mut vertex_attributes,
);
bind_group_layouts.insert(1, bind_group);
let vertex_buffer_layout = layout.0.get_layout(&vertex_attributes)?;
// Setup prepass fragment targets - normals in slot 0 (or None if not needed), motion vectors in slot 1
let mut targets = vec![
key.mesh_key
.contains(MeshPipelineKey::NORMAL_PREPASS)
.then_some(ColorTargetState {
format: NORMAL_PREPASS_FORMAT,
// BlendState::REPLACE is not needed here, and None will be potentially much faster in some cases.
blend: None,
write_mask: ColorWrites::ALL,
}),
key.mesh_key
.contains(MeshPipelineKey::MOTION_VECTOR_PREPASS)
.then_some(ColorTargetState {
format: MOTION_VECTOR_PREPASS_FORMAT,
// BlendState::REPLACE is not needed here, and None will be potentially much faster in some cases.
blend: None,
write_mask: ColorWrites::ALL,
}),
key.mesh_key
.contains(MeshPipelineKey::DEFERRED_PREPASS)
.then_some(ColorTargetState {
format: DEFERRED_PREPASS_FORMAT,
// BlendState::REPLACE is not needed here, and None will be potentially much faster in some cases.
blend: None,
write_mask: ColorWrites::ALL,
}),
key.mesh_key
.contains(MeshPipelineKey::DEFERRED_PREPASS)
.then_some(ColorTargetState {
format: DEFERRED_LIGHTING_PASS_ID_FORMAT,
blend: None,
write_mask: ColorWrites::ALL,
}),
];
if targets.iter().all(Option::is_none) {
// if no targets are required then clear the list, so that no fragment shader is required
// (though one may still be used for discarding depth buffer writes)
targets.clear();
}
// The fragment shader is only used when the normal prepass or motion vectors prepass
// is enabled or the material uses alpha cutoff values and doesn't rely on the standard
// prepass shader or we are clamping the orthographic depth.
let fragment_required = !targets.is_empty()
|| key.mesh_key.contains(MeshPipelineKey::DEPTH_CLAMP_ORTHO)
|| (key.mesh_key.contains(MeshPipelineKey::MAY_DISCARD)
&& self.prepass_material_fragment_shader.is_some());
let fragment = fragment_required.then(|| {
// Use the fragment shader from the material
let frag_shader_handle = if key.mesh_key.contains(MeshPipelineKey::DEFERRED_PREPASS) {
match self.deferred_material_fragment_shader.clone() {
Some(frag_shader_handle) => frag_shader_handle,
_ => PREPASS_SHADER_HANDLE,
}
} else {
match self.prepass_material_fragment_shader.clone() {
Some(frag_shader_handle) => frag_shader_handle,
_ => PREPASS_SHADER_HANDLE,
}
};
FragmentState {
shader: frag_shader_handle,
entry_point: "fragment".into(),
shader_defs: shader_defs.clone(),
targets,
}
});
// Use the vertex shader from the material if present
let vert_shader_handle = if key.mesh_key.contains(MeshPipelineKey::DEFERRED_PREPASS) {
if let Some(handle) = &self.deferred_material_vertex_shader {
handle.clone()
} else {
PREPASS_SHADER_HANDLE
}
} else if let Some(handle) = &self.prepass_material_vertex_shader {
handle.clone()
} else {
PREPASS_SHADER_HANDLE
};
let mut push_constant_ranges = Vec::with_capacity(1);
if cfg!(all(
feature = "webgl",
target_arch = "wasm32",
not(feature = "webgpu")
)) {
push_constant_ranges.push(PushConstantRange {
stages: ShaderStages::VERTEX,
range: 0..4,
});
}
let mut descriptor = RenderPipelineDescriptor {
vertex: VertexState {
shader: vert_shader_handle,
entry_point: "vertex".into(),
shader_defs,
buffers: vec![vertex_buffer_layout],
},
fragment,
layout: bind_group_layouts,
primitive: PrimitiveState {
topology: key.mesh_key.primitive_topology(),
strip_index_format: None,
front_face: FrontFace::Ccw,
cull_mode: None,
unclipped_depth: false,
polygon_mode: PolygonMode::Fill,
conservative: false,
},
depth_stencil: Some(DepthStencilState {
format: CORE_3D_DEPTH_FORMAT,
depth_write_enabled: true,
depth_compare: CompareFunction::GreaterEqual,
stencil: StencilState {
front: StencilFaceState::IGNORE,
back: StencilFaceState::IGNORE,
read_mask: 0,
write_mask: 0,
},
bias: DepthBiasState {
constant: 0,
slope_scale: 0.0,
clamp: 0.0,
},
}),
multisample: MultisampleState {
count: key.mesh_key.msaa_samples(),
mask: !0,
alpha_to_coverage_enabled: false,
},
push_constant_ranges,
label: Some("prepass_pipeline".into()),
};
// This is a bit risky because it's possible to change something that would
// break the prepass but be fine in the main pass.
// Since this api is pretty low-level it doesn't matter that much, but it is a potential issue.
M::specialize(&self.material_pipeline, &mut descriptor, layout, key)?;
Ok(descriptor)
}
}
// Extract the render phases for the prepass
pub fn extract_camera_previous_view_data(
mut commands: Commands,
cameras_3d: Extract<Query<(Entity, &Camera, Option<&PreviousViewData>), With<Camera3d>>>,
) {
for (entity, camera, maybe_previous_view_data) in cameras_3d.iter() {
if camera.is_active {
let mut entity = commands.get_or_spawn(entity);
if let Some(previous_view_data) = maybe_previous_view_data {
entity.insert(previous_view_data.clone());
}
}
}
}
#[derive(Resource, Default)]
pub struct PreviousViewProjectionUniforms {
pub uniforms: DynamicUniformBuffer<PreviousViewData>,
}
#[derive(Component)]
pub struct PreviousViewUniformOffset {
pub offset: u32,
}
pub fn prepare_previous_view_uniforms(
mut commands: Commands,
render_device: Res<RenderDevice>,
render_queue: Res<RenderQueue>,
mut view_uniforms: ResMut<PreviousViewProjectionUniforms>,
views: Query<(Entity, &ExtractedView, Option<&PreviousViewData>), With<MotionVectorPrepass>>,
) {
let views_iter = views.iter();
let view_count = views_iter.len();
let Some(mut writer) =
view_uniforms
.uniforms
.get_writer(view_count, &render_device, &render_queue)
else {
return;
};
for (entity, camera, maybe_previous_view_uniforms) in views_iter {
let view_projection = match maybe_previous_view_uniforms {
Some(previous_view) => previous_view.clone(),
None => {
let inverse_view = camera.transform.compute_matrix().inverse();
PreviousViewData {
inverse_view,
view_proj: camera.projection * inverse_view,
}
}
};
commands.entity(entity).insert(PreviousViewUniformOffset {
offset: writer.write(&view_projection),
});
}
}
#[derive(Default, Resource)]
pub struct PrepassViewBindGroup {
pub motion_vectors: Option<BindGroup>,
pub no_motion_vectors: Option<BindGroup>,
}
pub fn prepare_prepass_view_bind_group<M: Material>(
render_device: Res<RenderDevice>,
prepass_pipeline: Res<PrepassPipeline<M>>,
view_uniforms: Res<ViewUniforms>,
globals_buffer: Res<GlobalsBuffer>,
previous_view_uniforms: Res<PreviousViewProjectionUniforms>,
mut prepass_view_bind_group: ResMut<PrepassViewBindGroup>,
) {
if let (Some(view_binding), Some(globals_binding)) = (
view_uniforms.uniforms.binding(),
globals_buffer.buffer.binding(),
) {
prepass_view_bind_group.no_motion_vectors = Some(render_device.create_bind_group(
"prepass_view_no_motion_vectors_bind_group",
&prepass_pipeline.view_layout_no_motion_vectors,
&BindGroupEntries::sequential((view_binding.clone(), globals_binding.clone())),
));
if let Some(previous_view_uniforms_binding) = previous_view_uniforms.uniforms.binding() {
prepass_view_bind_group.motion_vectors = Some(render_device.create_bind_group(
"prepass_view_motion_vectors_bind_group",
&prepass_pipeline.view_layout_motion_vectors,
&BindGroupEntries::sequential((
view_binding,
globals_binding,
previous_view_uniforms_binding,
)),
));
}
}
}
#[allow(clippy::too_many_arguments)]
pub fn queue_prepass_material_meshes<M: Material>(
opaque_draw_functions: Res<DrawFunctions<Opaque3dPrepass>>,
alpha_mask_draw_functions: Res<DrawFunctions<AlphaMask3dPrepass>>,
opaque_deferred_draw_functions: Res<DrawFunctions<Opaque3dDeferred>>,
alpha_mask_deferred_draw_functions: Res<DrawFunctions<AlphaMask3dDeferred>>,
prepass_pipeline: Res<PrepassPipeline<M>>,
mut pipelines: ResMut<SpecializedMeshPipelines<PrepassPipeline<M>>>,
pipeline_cache: Res<PipelineCache>,
msaa: Res<Msaa>,
render_meshes: Res<RenderAssets<GpuMesh>>,
render_mesh_instances: Res<RenderMeshInstances>,
render_materials: Res<RenderAssets<PreparedMaterial<M>>>,
render_material_instances: Res<RenderMaterialInstances<M>>,
render_lightmaps: Res<RenderLightmaps>,
mut views: Query<
(
&ExtractedView,
&VisibleEntities,
Option<&mut BinnedRenderPhase<Opaque3dPrepass>>,
Option<&mut BinnedRenderPhase<AlphaMask3dPrepass>>,
Option<&mut BinnedRenderPhase<Opaque3dDeferred>>,
Option<&mut BinnedRenderPhase<AlphaMask3dDeferred>>,
Option<&DepthPrepass>,
Option<&NormalPrepass>,
Option<&MotionVectorPrepass>,
Option<&DeferredPrepass>,
),
Or<(
With<BinnedRenderPhase<Opaque3dPrepass>>,
With<BinnedRenderPhase<AlphaMask3dPrepass>>,
With<BinnedRenderPhase<Opaque3dDeferred>>,
With<BinnedRenderPhase<AlphaMask3dDeferred>>,
)>,
>,
) where
M::Data: PartialEq + Eq + Hash + Clone,
{
let opaque_draw_prepass = opaque_draw_functions
.read()
.get_id::<DrawPrepass<M>>()
.unwrap();
let alpha_mask_draw_prepass = alpha_mask_draw_functions
.read()
.get_id::<DrawPrepass<M>>()
.unwrap();
let opaque_draw_deferred = opaque_deferred_draw_functions
.read()
.get_id::<DrawPrepass<M>>()
.unwrap();
let alpha_mask_draw_deferred = alpha_mask_deferred_draw_functions
.read()
.get_id::<DrawPrepass<M>>()
.unwrap();
for (
_view,
visible_entities,
mut opaque_phase,
mut alpha_mask_phase,
mut opaque_deferred_phase,
mut alpha_mask_deferred_phase,
depth_prepass,
normal_prepass,
motion_vector_prepass,
deferred_prepass,
) in &mut views
{
let mut view_key = MeshPipelineKey::from_msaa_samples(msaa.samples());
if depth_prepass.is_some() {
view_key |= MeshPipelineKey::DEPTH_PREPASS;
}
if normal_prepass.is_some() {
view_key |= MeshPipelineKey::NORMAL_PREPASS;
}
if motion_vector_prepass.is_some() {
view_key |= MeshPipelineKey::MOTION_VECTOR_PREPASS;
}
for visible_entity in &visible_entities.entities {
let Some(material_asset_id) = render_material_instances.get(visible_entity) else {
continue;
};
let Some(mesh_instance) = render_mesh_instances.render_mesh_queue_data(*visible_entity)
else {
continue;
};
let Some(material) = render_materials.get(*material_asset_id) else {
continue;
};
let Some(mesh) = render_meshes.get(mesh_instance.mesh_asset_id) else {
continue;
};
let mut mesh_key = view_key | MeshPipelineKey::from_bits_retain(mesh.key_bits.bits());
let alpha_mode = material.properties.alpha_mode;
match alpha_mode {
AlphaMode::Opaque => {}
AlphaMode::Mask(_) => mesh_key |= MeshPipelineKey::MAY_DISCARD,
AlphaMode::Blend
| AlphaMode::Premultiplied
| AlphaMode::Add
| AlphaMode::Multiply => continue,
}
if material.properties.reads_view_transmission_texture {
// No-op: Materials reading from `ViewTransmissionTexture` are not rendered in the `Opaque3d`
// phase, and are therefore also excluded from the prepass much like alpha-blended materials.
continue;
}
let forward = match material.properties.render_method {
OpaqueRendererMethod::Forward => true,
OpaqueRendererMethod::Deferred => false,
OpaqueRendererMethod::Auto => unreachable!(),
};
let deferred = deferred_prepass.is_some() && !forward;
if deferred {
mesh_key |= MeshPipelineKey::DEFERRED_PREPASS;
}
// Even though we don't use the lightmap in the prepass, the
// `SetMeshBindGroup` render command will bind the data for it. So
// we need to include the appropriate flag in the mesh pipeline key
// to ensure that the necessary bind group layout entries are
// present.
if render_lightmaps
.render_lightmaps
.contains_key(visible_entity)
{
mesh_key |= MeshPipelineKey::LIGHTMAPPED;
}
let pipeline_id = pipelines.specialize(
&pipeline_cache,
&prepass_pipeline,
MaterialPipelineKey {
mesh_key,
bind_group_data: material.key.clone(),
},
&mesh.layout,
);
let pipeline_id = match pipeline_id {
Ok(id) => id,
Err(err) => {
error!("{}", err);
continue;
}
};
match alpha_mode {
AlphaMode::Opaque => {
if deferred {
opaque_deferred_phase.as_mut().unwrap().add(
OpaqueNoLightmap3dBinKey {
draw_function: opaque_draw_deferred,
pipeline: pipeline_id,
asset_id: mesh_instance.mesh_asset_id,
material_bind_group_id: material.get_bind_group_id().0,
},
*visible_entity,
mesh_instance.should_batch(),
);
} else if let Some(opaque_phase) = opaque_phase.as_mut() {
opaque_phase.add(
OpaqueNoLightmap3dBinKey {
draw_function: opaque_draw_prepass,
pipeline: pipeline_id,
asset_id: mesh_instance.mesh_asset_id,
material_bind_group_id: material.get_bind_group_id().0,
},
*visible_entity,
mesh_instance.should_batch(),
);
}
}
AlphaMode::Mask(_) => {
if deferred {
let bin_key = OpaqueNoLightmap3dBinKey {
pipeline: pipeline_id,
draw_function: alpha_mask_draw_deferred,
asset_id: mesh_instance.mesh_asset_id,
material_bind_group_id: material.get_bind_group_id().0,
};
alpha_mask_deferred_phase.as_mut().unwrap().add(
bin_key,
*visible_entity,
mesh_instance.should_batch(),
);
} else if let Some(alpha_mask_phase) = alpha_mask_phase.as_mut() {
let bin_key = OpaqueNoLightmap3dBinKey {
pipeline: pipeline_id,
draw_function: alpha_mask_draw_prepass,
asset_id: mesh_instance.mesh_asset_id,
material_bind_group_id: material.get_bind_group_id().0,
};
alpha_mask_phase.add(
bin_key,
*visible_entity,
mesh_instance.should_batch(),
);
}
}
AlphaMode::Blend
| AlphaMode::Premultiplied
| AlphaMode::Add
| AlphaMode::Multiply => {}
}
}
}
}
pub struct SetPrepassViewBindGroup<const I: usize>;
impl<P: PhaseItem, const I: usize> RenderCommand<P> for SetPrepassViewBindGroup<I> {
type Param = SRes<PrepassViewBindGroup>;
type ViewQuery = (
Read<ViewUniformOffset>,
Option<Read<PreviousViewUniformOffset>>,
);
type ItemQuery = ();
#[inline]
fn render<'w>(
_item: &P,
(view_uniform_offset, previous_view_uniform_offset): (
&'_ ViewUniformOffset,
Option<&'_ PreviousViewUniformOffset>,
),
_entity: Option<()>,
prepass_view_bind_group: SystemParamItem<'w, '_, Self::Param>,
pass: &mut TrackedRenderPass<'w>,
) -> RenderCommandResult {
let prepass_view_bind_group = prepass_view_bind_group.into_inner();
if let Some(previous_view_uniform_offset) = previous_view_uniform_offset {
pass.set_bind_group(
I,
prepass_view_bind_group.motion_vectors.as_ref().unwrap(),
&[
view_uniform_offset.offset,
previous_view_uniform_offset.offset,
],
);
} else {
pass.set_bind_group(
I,
prepass_view_bind_group.no_motion_vectors.as_ref().unwrap(),
&[view_uniform_offset.offset],
);
}
RenderCommandResult::Success
}
}
pub type DrawPrepass<M> = (
SetItemPipeline,
SetPrepassViewBindGroup<0>,
SetMeshBindGroup<1>,
SetMaterialBindGroup<M, 2>,
DrawMesh,
);