Merge branch 'main' into 3d-fixed-timestep

crates/bevy_core_widgets/src/core_button.rs

@@ -2,6 +2,7 @@ use accesskit::Role;
 use bevy_a11y::AccessibilityNode;
 use bevy_app::{App, Plugin};
 use bevy_ecs::query::Has;
+use bevy_ecs::system::In;
 use bevy_ecs::{
     component::Component,
     entity::Entity,
@@ -15,7 +16,7 @@ use bevy_input_focus::FocusedInput;
 use bevy_picking::events::{Cancel, Click, DragEnd, Pointer, Press, Release};
 use bevy_ui::{InteractionDisabled, Pressed};
 
-use crate::{Callback, Notify};
+use crate::{Activate, Callback, Notify};
 
 /// Headless button widget. This widget maintains a "pressed" state, which is used to
 /// indicate whether the button is currently being pressed by the user. It emits a `ButtonClicked`
@@ -25,7 +26,7 @@ use crate::{Callback, Notify};
 pub struct CoreButton {
     /// Callback to invoke when the button is clicked, or when the `Enter` or `Space` key
     /// is pressed while the button is focused.
-    pub on_activate: Callback,
+    pub on_activate: Callback<In<Activate>>,
 }
 
 fn button_on_key_event(
@@ -41,7 +42,7 @@ fn button_on_key_event(
                 && (event.key_code == KeyCode::Enter || event.key_code == KeyCode::Space)
             {
                 trigger.propagate(false);
-                commands.notify(&bstate.on_activate);
+                commands.notify_with(&bstate.on_activate, Activate(trigger.target()));
             }
         }
     }
@@ -55,7 +56,7 @@ fn button_on_pointer_click(
     if let Ok((bstate, pressed, disabled)) = q_state.get_mut(trigger.target()) {
         trigger.propagate(false);
         if pressed && !disabled {
-            commands.notify(&bstate.on_activate);
+            commands.notify_with(&bstate.on_activate, Activate(trigger.target()));
         }
     }
 }

crates/bevy_core_widgets/src/core_checkbox.rs

@@ -15,7 +15,7 @@ use bevy_input_focus::{FocusedInput, InputFocus, InputFocusVisible};
 use bevy_picking::events::{Click, Pointer};
 use bevy_ui::{Checkable, Checked, InteractionDisabled};
 
-use crate::{Callback, Notify as _};
+use crate::{Callback, Notify as _, ValueChange};
 
 /// Headless widget implementation for checkboxes. The [`Checked`] component represents the current
 /// state of the checkbox. The `on_change` field is an optional system id that will be run when the
@@ -34,7 +34,7 @@ pub struct CoreCheckbox {
     /// One-shot system that is run when the checkbox state needs to be changed. If this value is
     /// `Callback::Ignore`, then the checkbox will update it's own internal [`Checked`] state
     /// without notification.
-    pub on_change: Callback<In<bool>>,
+    pub on_change: Callback<In<ValueChange<bool>>>,
 }
 
 fn checkbox_on_key_input(
@@ -162,7 +162,13 @@ fn set_checkbox_state(
     new_state: bool,
 ) {
     if !matches!(checkbox.on_change, Callback::Ignore) {
-        commands.notify_with(&checkbox.on_change, new_state);
+        commands.notify_with(
+            &checkbox.on_change,
+            ValueChange {
+                source: entity.into(),
+                value: new_state,
+            },
+        );
     } else if new_state {
         commands.entity(entity.into()).insert(Checked);
     } else {

crates/bevy_core_widgets/src/core_radio.rs

@@ -6,7 +6,6 @@ use bevy_ecs::query::Has;
 use bevy_ecs::system::In;
 use bevy_ecs::{
     component::Component,
-    entity::Entity,
     observer::On,
     query::With,
     system::{Commands, Query},
@@ -17,7 +16,7 @@ use bevy_input_focus::FocusedInput;
 use bevy_picking::events::{Click, Pointer};
 use bevy_ui::{Checkable, Checked, InteractionDisabled};
 
-use crate::{Callback, Notify};
+use crate::{Activate, Callback, Notify};
 
 /// Headless widget implementation for a "radio button group". This component is used to group
 /// multiple [`CoreRadio`] components together, allowing them to behave as a single unit. It
@@ -38,7 +37,7 @@ use crate::{Callback, Notify};
 #[require(AccessibilityNode(accesskit::Node::new(Role::RadioGroup)))]
 pub struct CoreRadioGroup {
     /// Callback which is called when the selected radio button changes.
-    pub on_change: Callback<In<Entity>>,
+    pub on_change: Callback<In<Activate>>,
 }
 
 /// Headless widget implementation for radio buttons. These should be enclosed within a
@@ -133,7 +132,7 @@ fn radio_group_on_key_input(
             let (next_id, _) = radio_buttons[next_index];
 
             // Trigger the on_change event for the newly checked radio button
-            commands.notify_with(on_change, next_id);
+            commands.notify_with(on_change, Activate(next_id));
         }
     }
 }
@@ -201,7 +200,7 @@ fn radio_group_on_button_click(
         }
 
         // Trigger the on_change event for the newly checked radio button
-        commands.notify_with(on_change, radio_id);
+        commands.notify_with(on_change, Activate(radio_id));
     }
 }
 

crates/bevy_core_widgets/src/core_slider.rs

@@ -23,7 +23,7 @@ use bevy_math::ops;
 use bevy_picking::events::{Drag, DragEnd, DragStart, Pointer, Press};
 use bevy_ui::{ComputedNode, ComputedNodeTarget, InteractionDisabled, UiGlobalTransform, UiScale};
 
-use crate::{Callback, Notify};
+use crate::{Callback, Notify, ValueChange};
 
 /// Defines how the slider should behave when you click on the track (not the thumb).
 #[derive(Debug, Default, PartialEq, Clone, Copy)]
@@ -78,7 +78,7 @@ pub struct CoreSlider {
     /// Callback which is called when the slider is dragged or the value is changed via other user
     /// interaction. If this value is `Callback::Ignore`, then the slider will update it's own
     /// internal [`SliderValue`] state without notification.
-    pub on_change: Callback<In<f32>>,
+    pub on_change: Callback<In<ValueChange<f32>>>,
     /// Set the track-clicking behavior for this slider.
     pub track_click: TrackClick,
     // TODO: Think about whether we want a "vertical" option.
@@ -298,7 +298,13 @@ pub(crate) fn slider_on_pointer_down(
                 .entity(trigger.target())
                 .insert(SliderValue(new_value));
         } else {
-            commands.notify_with(&slider.on_change, new_value);
+            commands.notify_with(
+                &slider.on_change,
+                ValueChange {
+                    source: trigger.target(),
+                    value: new_value,
+                },
+            );
         }
     }
 }
@@ -370,7 +376,13 @@ pub(crate) fn slider_on_drag(
                     .entity(trigger.target())
                     .insert(SliderValue(rounded_value));
             } else {
-                commands.notify_with(&slider.on_change, rounded_value);
+                commands.notify_with(
+                    &slider.on_change,
+                    ValueChange {
+                        source: trigger.target(),
+                        value: rounded_value,
+                    },
+                );
             }
         }
     }
@@ -417,7 +429,13 @@ fn slider_on_key_input(
                     .entity(trigger.target())
                     .insert(SliderValue(new_value));
             } else {
-                commands.notify_with(&slider.on_change, new_value);
+                commands.notify_with(
+                    &slider.on_change,
+                    ValueChange {
+                        source: trigger.target(),
+                        value: new_value,
+                    },
+                );
             }
         }
     }
@@ -509,7 +527,13 @@ fn slider_on_set_value(
                 .entity(trigger.target())
                 .insert(SliderValue(new_value));
         } else {
-            commands.notify_with(&slider.on_change, new_value);
+            commands.notify_with(
+                &slider.on_change,
+                ValueChange {
+                    source: trigger.target(),
+                    value: new_value,
+                },
+            );
         }
     }
 }

crates/bevy_core_widgets/src/lib.rs

@@ -23,6 +23,7 @@ mod core_slider;
 
 use bevy_app::{PluginGroup, PluginGroupBuilder};
 
+use bevy_ecs::entity::Entity;
 pub use callback::{Callback, Notify};
 pub use core_button::{CoreButton, CoreButtonPlugin};
 pub use core_checkbox::{CoreCheckbox, CoreCheckboxPlugin, SetChecked, ToggleChecked};
@@ -50,3 +51,16 @@ impl PluginGroup for CoreWidgetsPlugins {
             .add(CoreSliderPlugin)
     }
 }
+
+/// Notification sent by a button or menu item.
+#[derive(Copy, Clone, Debug, PartialEq)]
+pub struct Activate(pub Entity);
+
+/// Notification sent by a widget that edits a scalar value.
+#[derive(Copy, Clone, Debug, PartialEq)]
+pub struct ValueChange<T> {
+    /// The id of the widget that produced this value.
+    pub source: Entity,
+    /// The new value.
+    pub value: T,
+}

crates/bevy_diagnostic/Cargo.toml

@@ -71,14 +71,14 @@ log = { version = "0.4", default-features = false }
 # macOS
 [target.'cfg(all(target_os="macos"))'.dependencies]
 # Some features of sysinfo are not supported by apple. This will disable those features on apple devices
-sysinfo = { version = "0.35.0", optional = true, default-features = false, features = [
+sysinfo = { version = "0.36.0", optional = true, default-features = false, features = [
   "apple-app-store",
   "system",
 ] }
 
 # Only include when on linux/windows/android/freebsd
 [target.'cfg(any(target_os = "linux", target_os = "windows", target_os = "android", target_os = "freebsd"))'.dependencies]
-sysinfo = { version = "0.35.0", optional = true, default-features = false, features = [
+sysinfo = { version = "0.36.0", optional = true, default-features = false, features = [
   "system",
 ] }
 

crates/bevy_diagnostic/src/entity_count_diagnostics_plugin.rs

@@ -1,19 +1,38 @@
 use bevy_app::prelude::*;
 use bevy_ecs::entity::Entities;
 
-use crate::{Diagnostic, DiagnosticPath, Diagnostics, RegisterDiagnostic};
+use crate::{
+    Diagnostic, DiagnosticPath, Diagnostics, RegisterDiagnostic, DEFAULT_MAX_HISTORY_LENGTH,
+};
 
 /// Adds "entity count" diagnostic to an App.
 ///
 /// # See also
 ///
 /// [`LogDiagnosticsPlugin`](crate::LogDiagnosticsPlugin) to output diagnostics to the console.
-#[derive(Default)]
+pub struct EntityCountDiagnosticsPlugin {
-pub struct EntityCountDiagnosticsPlugin;
+    /// The total number of values to keep.
+    pub max_history_length: usize,
+}
+
+impl Default for EntityCountDiagnosticsPlugin {
+    fn default() -> Self {
+        Self::new(DEFAULT_MAX_HISTORY_LENGTH)
+    }
+}
+
+impl EntityCountDiagnosticsPlugin {
+    /// Creates a new `EntityCountDiagnosticsPlugin` with the specified `max_history_length`.
+    pub fn new(max_history_length: usize) -> Self {
+        Self { max_history_length }
+    }
+}
 
 impl Plugin for EntityCountDiagnosticsPlugin {
     fn build(&self, app: &mut App) {
-        app.register_diagnostic(Diagnostic::new(Self::ENTITY_COUNT))
+        app.register_diagnostic(
+            Diagnostic::new(Self::ENTITY_COUNT).with_max_history_length(self.max_history_length),
+        )
         .add_systems(Update, Self::diagnostic_system);
     }
 }

crates/bevy_ecs/src/schedule/schedule.rs

@@ -15,6 +15,7 @@ use bevy_utils::{default, prelude::DebugName, TypeIdMap};
 use core::{
     any::{Any, TypeId},
     fmt::{Debug, Write},
+    ops::Range,
 };
 use fixedbitset::FixedBitSet;
 use log::{error, info, warn};
@@ -658,29 +659,6 @@ impl Dag {
     }
 }
 
-/// A [`SystemSet`] with metadata, stored in a [`ScheduleGraph`].
-struct SystemSetNode {
-    inner: InternedSystemSet,
-}
-
-impl SystemSetNode {
-    pub fn new(set: InternedSystemSet) -> Self {
-        Self { inner: set }
-    }
-
-    pub fn name(&self) -> String {
-        format!("{:?}", &self.inner)
-    }
-
-    pub fn is_system_type(&self) -> bool {
-        self.inner.system_type().is_some()
-    }
-
-    pub fn is_anonymous(&self) -> bool {
-        self.inner.is_anonymous()
-    }
-}
-
 /// A [`SystemWithAccess`] stored in a [`ScheduleGraph`].
 pub struct SystemNode {
     inner: Option<SystemWithAccess>,
@@ -752,11 +730,31 @@ new_key_type! {
     pub struct SystemSetKey;
 }
 
+/// A node in a [`ScheduleGraph`] with a system or conditions that have not been
+/// initialized yet.
+///
+/// We have to defer initialization of nodes in the graph until we have
+/// `&mut World` access, so we store these in a list ([`ScheduleGraph::uninit`])
+/// until then. In most cases, initialization occurs upon the first run of the
+/// schedule.
 enum UninitializedId {
+    /// A system and its conditions that have not been initialized yet.
     System(SystemKey),
+    /// A system set's conditions that have not been initialized yet.
     Set {
         key: SystemSetKey,
-        first_uninit_condition: usize,
+        /// The range of indices in [`SystemSets::conditions`] that correspond
+        /// to conditions that have not been initialized yet.
+        ///
+        /// [`SystemSets::conditions`] for a given set may be appended to
+        /// multiple times (e.g. when `configure_sets` is called multiple with
+        /// the same set), so we need to track which conditions in that list
+        /// are newly added and not yet initialized.
+        ///
+        /// Systems don't need this tracking because each `add_systems` call
+        /// creates separate nodes in the graph with their own conditions,
+        /// so all conditions are initialized together.
+        uninitialized_conditions: Range<usize>,
     },
 }
 
@@ -764,7 +762,7 @@ enum UninitializedId {
 #[derive(Default)]
 struct SystemSets {
     /// List of system sets in the schedule
-    sets: SlotMap<SystemSetKey, SystemSetNode>,
+    sets: SlotMap<SystemSetKey, InternedSystemSet>,
     /// List of conditions for each system set, in the same order as `system_sets`
     conditions: SecondaryMap<SystemSetKey, Vec<ConditionWithAccess>>,
     /// Map from system set to node id
@@ -774,7 +772,7 @@ struct SystemSets {
 impl SystemSets {
     fn get_or_add_set(&mut self, set: InternedSystemSet) -> SystemSetKey {
         *self.ids.entry(set).or_insert_with(|| {
-            let key = self.sets.insert(SystemSetNode::new(set));
+            let key = self.sets.insert(set);
             self.conditions.insert(key, Vec::new());
             key
         })
@@ -793,8 +791,8 @@ pub struct ScheduleGraph {
     pub system_conditions: SecondaryMap<SystemKey, Vec<ConditionWithAccess>>,
     /// Data about system sets in the schedule
     system_sets: SystemSets,
-    /// Systems that have not been initialized yet; for system sets, we store the index of the first uninitialized condition
+    /// Systems, their conditions, and system set conditions that need to be
-    /// (all the conditions after that index still need to be initialized)
+    /// initialized before the schedule can be run.
     uninit: Vec<UninitializedId>,
     /// Directed acyclic graph of the hierarchy (which systems/sets are children of which sets)
     hierarchy: Dag,
@@ -807,7 +805,6 @@ pub struct ScheduleGraph {
     anonymous_sets: usize,
     changed: bool,
     settings: ScheduleBuildSettings,
-
     passes: BTreeMap<TypeId, Box<dyn ScheduleBuildPassObj>>,
 }
 
@@ -855,7 +852,7 @@ impl ScheduleGraph {
 
     /// Returns the set at the given [`NodeId`], if it exists.
     pub fn get_set_at(&self, key: SystemSetKey) -> Option<&dyn SystemSet> {
-        self.system_sets.sets.get(key).map(|set| &*set.inner)
+        self.system_sets.sets.get(key).map(|set| &**set)
     }
 
     /// Returns the set at the given [`NodeId`].
@@ -897,10 +894,9 @@ impl ScheduleGraph {
     pub fn system_sets(
         &self,
     ) -> impl Iterator<Item = (SystemSetKey, &dyn SystemSet, &[ConditionWithAccess])> {
-        self.system_sets.sets.iter().filter_map(|(key, set_node)| {
+        self.system_sets.sets.iter().filter_map(|(key, set)| {
-            let set = &*set_node.inner;
             let conditions = self.system_sets.conditions.get(key)?.as_slice();
-            Some((key, set, conditions))
+            Some((key, &**set, conditions))
         })
     }
 
@@ -1101,9 +1097,10 @@ impl ScheduleGraph {
 
         // system init has to be deferred (need `&mut World`)
         let system_set_conditions = self.system_sets.conditions.entry(key).unwrap().or_default();
+        let start = system_set_conditions.len();
         self.uninit.push(UninitializedId::Set {
             key,
-            first_uninit_condition: system_set_conditions.len(),
+            uninitialized_conditions: start..(start + conditions.len()),
         });
         system_set_conditions.extend(conditions.into_iter().map(ConditionWithAccess::new));
 
@@ -1189,11 +1186,9 @@ impl ScheduleGraph {
                 }
                 UninitializedId::Set {
                     key,
-                    first_uninit_condition,
+                    uninitialized_conditions,
                 } => {
-                    for condition in self.system_sets.conditions[key]
+                    for condition in &mut self.system_sets.conditions[key][uninitialized_conditions]
-                        .iter_mut()
-                        .skip(first_uninit_condition)
                     {
                         condition.access = condition.condition.initialize(world);
                     }
@@ -1685,7 +1680,7 @@ impl ScheduleGraph {
                 if set.is_anonymous() {
                     self.anonymous_set_name(id)
                 } else {
-                    set.name()
+                    format!("{set:?}")
                 }
             }
         }
@@ -1908,7 +1903,7 @@ impl ScheduleGraph {
     ) -> Result<(), ScheduleBuildError> {
         for (&key, systems) in set_systems {
             let set = &self.system_sets.sets[key];
-            if set.is_system_type() {
+            if set.system_type().is_some() {
                 let instances = systems.len();
                 let ambiguous_with = self.ambiguous_with.edges(NodeId::Set(key));
                 let before = self
@@ -2014,7 +2009,7 @@ impl ScheduleGraph {
     fn names_of_sets_containing_node(&self, id: &NodeId) -> Vec<String> {
         let mut sets = <HashSet<_>>::default();
         self.traverse_sets_containing_node(*id, &mut |key| {
-            !self.system_sets.sets[key].is_system_type() && sets.insert(key)
+            self.system_sets.sets[key].system_type().is_none() && sets.insert(key)
         });
         let mut sets: Vec<_> = sets
             .into_iter()

crates/bevy_feathers/src/controls/button.rs

@@ -1,5 +1,5 @@
 use bevy_app::{Plugin, PreUpdate};
-use bevy_core_widgets::{Callback, CoreButton};
+use bevy_core_widgets::{Activate, Callback, CoreButton};
 use bevy_ecs::{
     bundle::Bundle,
     component::Component,
@@ -9,7 +9,7 @@ use bevy_ecs::{
     query::{Added, Changed, Has, Or},
     schedule::IntoScheduleConfigs,
     spawn::{SpawnRelated, SpawnableList},
-    system::{Commands, Query},
+    system::{Commands, In, Query},
 };
 use bevy_input_focus::tab_navigation::TabIndex;
 use bevy_picking::{hover::Hovered, PickingSystems};
@@ -45,7 +45,7 @@ pub struct ButtonProps {
     /// Rounded corners options
     pub corners: RoundedCorners,
     /// Click handler
-    pub on_click: Callback,
+    pub on_click: Callback<In<Activate>>,
 }
 
 /// Template function to spawn a button.

crates/bevy_feathers/src/controls/checkbox.rs

@@ -1,5 +1,5 @@
 use bevy_app::{Plugin, PreUpdate};
-use bevy_core_widgets::{Callback, CoreCheckbox};
+use bevy_core_widgets::{Callback, CoreCheckbox, ValueChange};
 use bevy_ecs::{
     bundle::Bundle,
     children,
@@ -34,7 +34,7 @@ use crate::{
 #[derive(Default)]
 pub struct CheckboxProps {
     /// Change handler
-    pub on_change: Callback<In<bool>>,
+    pub on_change: Callback<In<ValueChange<bool>>>,
 }
 
 /// Marker for the checkbox frame (contains both checkbox and label)

crates/bevy_feathers/src/controls/slider.rs

@@ -2,7 +2,7 @@ use core::f32::consts::PI;
 
 use bevy_app::{Plugin, PreUpdate};
 use bevy_color::Color;
-use bevy_core_widgets::{Callback, CoreSlider, SliderRange, SliderValue, TrackClick};
+use bevy_core_widgets::{Callback, CoreSlider, SliderRange, SliderValue, TrackClick, ValueChange};
 use bevy_ecs::{
     bundle::Bundle,
     children,
@@ -42,7 +42,7 @@ pub struct SliderProps {
     /// Slider maximum value
     pub max: f32,
     /// On-change handler
-    pub on_change: Callback<In<f32>>,
+    pub on_change: Callback<In<ValueChange<f32>>>,
 }
 
 impl Default for SliderProps {

crates/bevy_feathers/src/controls/toggle_switch.rs

@@ -1,7 +1,7 @@
 use accesskit::Role;
 use bevy_a11y::AccessibilityNode;
 use bevy_app::{Plugin, PreUpdate};
-use bevy_core_widgets::{Callback, CoreCheckbox};
+use bevy_core_widgets::{Callback, CoreCheckbox, ValueChange};
 use bevy_ecs::{
     bundle::Bundle,
     children,
@@ -30,7 +30,7 @@ use crate::{
 #[derive(Default)]
 pub struct ToggleSwitchProps {
     /// Change handler
-    pub on_change: Callback<In<bool>>,
+    pub on_change: Callback<In<ValueChange<bool>>>,
 }
 
 /// Marker for the toggle switch outline

crates/bevy_gltf/src/convert_coordinates.rs

@@ -24,6 +24,7 @@ pub(crate) trait ConvertCameraCoordinates {
     /// - up: Y
     /// - right: X
     ///
+    /// The same convention is used for lights.
     /// See <https://registry.khronos.org/glTF/specs/2.0/glTF-2.0.html#view-matrix>
     fn convert_camera_coordinates(self) -> Self;
 }

crates/bevy_gltf/src/loader/gltf_ext/scene.rs

@@ -45,7 +45,7 @@ pub(crate) fn node_transform(node: &Node, convert_coordinates: bool) -> Transfor
         },
     };
     if convert_coordinates {
-        if node.camera().is_some() {
+        if node.camera().is_some() || node.light().is_some() {
             transform.convert_camera_coordinates()
         } else {
             transform.convert_coordinates()

crates/bevy_reflect/derive/src/impls/typed.rs

@@ -106,12 +106,6 @@ pub(crate) fn impl_type_path(meta: &ReflectMeta) -> TokenStream {
     quote! {
         #primitive_assert
 
-        // To ensure alloc is available, but also prevent its name from clashing, we place the implementation inside an anonymous constant
-        const _: () = {
-            extern crate alloc;
-
-            use alloc::string::ToString;
-
         impl #impl_generics #bevy_reflect_path::TypePath for #type_path #ty_generics #where_reflect_clause {
             fn type_path() -> &'static str {
                 #long_type_path
@@ -133,7 +127,6 @@ pub(crate) fn impl_type_path(meta: &ReflectMeta) -> TokenStream {
                 #module_path
             }
         }
-        };
     }
 }
 

crates/bevy_solari/src/lib.rs

@@ -26,11 +26,13 @@ use bevy_render::settings::WgpuFeatures;
 /// An experimental set of plugins for raytraced lighting.
 ///
 /// This plugin group provides:
-/// * [`SolariLightingPlugin`] - Raytraced direct and indirect lighting (indirect lighting not yet implemented).
+/// * [`SolariLightingPlugin`] - Raytraced direct and indirect lighting.
 /// * [`RaytracingScenePlugin`] - BLAS building, resource and lighting binding.
+///
+/// There's also:
 /// * [`pathtracer::PathtracingPlugin`] - A non-realtime pathtracer for validation purposes (not added by default).
 ///
-/// To get started, add `RaytracingMesh3d` and `MeshMaterial3d::<StandardMaterial>` to your entities.
+/// To get started, add this plugin to your app, and then add `RaytracingMesh3d` and `MeshMaterial3d::<StandardMaterial>` to your entities.
 pub struct SolariPlugins;
 
 impl PluginGroup for SolariPlugins {

crates/bevy_solari/src/pathtracer/pathtracer.wgsl

@@ -47,7 +47,8 @@ fn pathtrace(@builtin(global_invocation_id) global_id: vec3<u32>) {
             if ray_t_min == 0.0 { radiance = ray_hit.material.emissive; }
 
             // Sample direct lighting
-            radiance += throughput * diffuse_brdf * sample_random_light(ray_hit.world_position, ray_hit.world_normal, &rng);
+            let direct_lighting = sample_random_light(ray_hit.world_position, ray_hit.world_normal, &rng);
+            radiance += throughput * diffuse_brdf * direct_lighting.radiance * direct_lighting.inverse_pdf;
 
             // Sample new ray direction from the material BRDF for next bounce
             ray_direction = sample_cosine_hemisphere(ray_hit.world_normal, &rng);

crates/bevy_solari/src/realtime/mod.rs

@@ -23,11 +23,16 @@ use node::SolariLightingNode;
 use prepare::prepare_solari_lighting_resources;
 use tracing::warn;
 
+/// Raytraced direct and indirect lighting.
+///
+/// When using this plugin, it's highly recommended to set `shadows_enabled: false` on all lights, as Solari replaces
+/// traditional shadow mapping.
 pub struct SolariLightingPlugin;
 
 impl Plugin for SolariLightingPlugin {
     fn build(&self, app: &mut App) {
         embedded_asset!(app, "restir_di.wgsl");
+        embedded_asset!(app, "restir_gi.wgsl");
 
         app.register_type::<SolariLighting>()
             .insert_resource(DefaultOpaqueRendererMethod::deferred());

crates/bevy_solari/src/realtime/node.rs

@@ -36,8 +36,10 @@ pub mod graph {
 
 pub struct SolariLightingNode {
     bind_group_layout: BindGroupLayout,
-    initial_and_temporal_pipeline: CachedComputePipelineId,
+    di_initial_and_temporal_pipeline: CachedComputePipelineId,
-    spatial_and_shade_pipeline: CachedComputePipelineId,
+    di_spatial_and_shade_pipeline: CachedComputePipelineId,
+    gi_initial_and_temporal_pipeline: CachedComputePipelineId,
+    gi_spatial_and_shade_pipeline: CachedComputePipelineId,
 }
 
 impl ViewNode for SolariLightingNode {
@@ -72,8 +74,10 @@ impl ViewNode for SolariLightingNode {
         let previous_view_uniforms = world.resource::<PreviousViewUniforms>();
         let frame_count = world.resource::<FrameCount>();
         let (
-            Some(initial_and_temporal_pipeline),
+            Some(di_initial_and_temporal_pipeline),
-            Some(spatial_and_shade_pipeline),
+            Some(di_spatial_and_shade_pipeline),
+            Some(gi_initial_and_temporal_pipeline),
+            Some(gi_spatial_and_shade_pipeline),
             Some(scene_bindings),
             Some(viewport),
             Some(gbuffer),
@@ -82,8 +86,10 @@ impl ViewNode for SolariLightingNode {
             Some(view_uniforms),
             Some(previous_view_uniforms),
         ) = (
-            pipeline_cache.get_compute_pipeline(self.initial_and_temporal_pipeline),
+            pipeline_cache.get_compute_pipeline(self.di_initial_and_temporal_pipeline),
-            pipeline_cache.get_compute_pipeline(self.spatial_and_shade_pipeline),
+            pipeline_cache.get_compute_pipeline(self.di_spatial_and_shade_pipeline),
+            pipeline_cache.get_compute_pipeline(self.gi_initial_and_temporal_pipeline),
+            pipeline_cache.get_compute_pipeline(self.gi_spatial_and_shade_pipeline),
             &scene_bindings.bind_group,
             camera.physical_viewport_size,
             view_prepass_textures.deferred_view(),
@@ -101,8 +107,18 @@ impl ViewNode for SolariLightingNode {
             &self.bind_group_layout,
             &BindGroupEntries::sequential((
                 view_target.get_unsampled_color_attachment().view,
-                solari_lighting_resources.reservoirs_a.as_entire_binding(),
+                solari_lighting_resources
-                solari_lighting_resources.reservoirs_b.as_entire_binding(),
+                    .di_reservoirs_a
+                    .as_entire_binding(),
+                solari_lighting_resources
+                    .di_reservoirs_b
+                    .as_entire_binding(),
+                solari_lighting_resources
+                    .gi_reservoirs_a
+                    .as_entire_binding(),
+                solari_lighting_resources
+                    .gi_reservoirs_b
+                    .as_entire_binding(),
                 gbuffer,
                 depth_buffer,
                 motion_vectors,
@@ -135,14 +151,20 @@ impl ViewNode for SolariLightingNode {
             ],
         );
 
-        pass.set_pipeline(initial_and_temporal_pipeline);
+        pass.set_pipeline(di_initial_and_temporal_pipeline);
         pass.set_push_constants(
             0,
             bytemuck::cast_slice(&[frame_index, solari_lighting.reset as u32]),
         );
         pass.dispatch_workgroups(viewport.x.div_ceil(8), viewport.y.div_ceil(8), 1);
 
-        pass.set_pipeline(spatial_and_shade_pipeline);
+        pass.set_pipeline(di_spatial_and_shade_pipeline);
+        pass.dispatch_workgroups(viewport.x.div_ceil(8), viewport.y.div_ceil(8), 1);
+
+        pass.set_pipeline(gi_initial_and_temporal_pipeline);
+        pass.dispatch_workgroups(viewport.x.div_ceil(8), viewport.y.div_ceil(8), 1);
+
+        pass.set_pipeline(gi_spatial_and_shade_pipeline);
         pass.dispatch_workgroups(viewport.x.div_ceil(8), viewport.y.div_ceil(8), 1);
 
         pass_span.end(&mut pass);
@@ -189,10 +211,12 @@ impl FromWorld for SolariLightingNode {
                 (
                     texture_storage_2d(
                         ViewTarget::TEXTURE_FORMAT_HDR,
-                        StorageTextureAccess::WriteOnly,
+                        StorageTextureAccess::ReadWrite,
                     ),
                     storage_buffer_sized(false, None),
                     storage_buffer_sized(false, None),
+                    storage_buffer_sized(false, None),
+                    storage_buffer_sized(false, None),
                     texture_2d(TextureSampleType::Uint),
                     texture_depth_2d(),
                     texture_2d(TextureSampleType::Float { filterable: true }),
@@ -204,9 +228,9 @@ impl FromWorld for SolariLightingNode {
             ),
         );
 
-        let initial_and_temporal_pipeline =
+        let di_initial_and_temporal_pipeline =
             pipeline_cache.queue_compute_pipeline(ComputePipelineDescriptor {
-                label: Some("solari_lighting_initial_and_temporal_pipeline".into()),
+                label: Some("solari_lighting_di_initial_and_temporal_pipeline".into()),
                 layout: vec![
                     scene_bindings.bind_group_layout.clone(),
                     bind_group_layout.clone(),
@@ -220,9 +244,9 @@ impl FromWorld for SolariLightingNode {
                 ..default()
             });
 
-        let spatial_and_shade_pipeline =
+        let di_spatial_and_shade_pipeline =
             pipeline_cache.queue_compute_pipeline(ComputePipelineDescriptor {
-                label: Some("solari_lighting_spatial_and_shade_pipeline".into()),
+                label: Some("solari_lighting_di_spatial_and_shade_pipeline".into()),
                 layout: vec![
                     scene_bindings.bind_group_layout.clone(),
                     bind_group_layout.clone(),
@@ -236,10 +260,46 @@ impl FromWorld for SolariLightingNode {
                 ..default()
             });
 
+        let gi_initial_and_temporal_pipeline =
+            pipeline_cache.queue_compute_pipeline(ComputePipelineDescriptor {
+                label: Some("solari_lighting_gi_initial_and_temporal_pipeline".into()),
+                layout: vec![
+                    scene_bindings.bind_group_layout.clone(),
+                    bind_group_layout.clone(),
+                ],
+                push_constant_ranges: vec![PushConstantRange {
+                    stages: ShaderStages::COMPUTE,
+                    range: 0..8,
+                }],
+                shader: load_embedded_asset!(world, "restir_gi.wgsl"),
+                shader_defs: vec![],
+                entry_point: Some("initial_and_temporal".into()),
+                zero_initialize_workgroup_memory: false,
+            });
+
+        let gi_spatial_and_shade_pipeline =
+            pipeline_cache.queue_compute_pipeline(ComputePipelineDescriptor {
+                label: Some("solari_lighting_gi_spatial_and_shade_pipeline".into()),
+                layout: vec![
+                    scene_bindings.bind_group_layout.clone(),
+                    bind_group_layout.clone(),
+                ],
+                push_constant_ranges: vec![PushConstantRange {
+                    stages: ShaderStages::COMPUTE,
+                    range: 0..8,
+                }],
+                shader: load_embedded_asset!(world, "restir_gi.wgsl"),
+                shader_defs: vec![],
+                entry_point: Some("spatial_and_shade".into()),
+                zero_initialize_workgroup_memory: false,
+            });
+
         Self {
             bind_group_layout,
-            initial_and_temporal_pipeline,
+            di_initial_and_temporal_pipeline,
-            spatial_and_shade_pipeline,
+            di_spatial_and_shade_pipeline,
+            gi_initial_and_temporal_pipeline,
+            gi_spatial_and_shade_pipeline,
         }
     }
 }

crates/bevy_solari/src/realtime/prepare.rs

@@ -17,14 +17,19 @@ use bevy_render::{
     renderer::RenderDevice,
 };
 
-/// Size of a Reservoir shader struct in bytes.
+/// Size of a DI Reservoir shader struct in bytes.
-const RESERVOIR_STRUCT_SIZE: u64 = 32;
+const DI_RESERVOIR_STRUCT_SIZE: u64 = 32;
+
+/// Size of a GI Reservoir shader struct in bytes.
+const GI_RESERVOIR_STRUCT_SIZE: u64 = 48;
 
 /// Internal rendering resources used for Solari lighting.
 #[derive(Component)]
 pub struct SolariLightingResources {
-    pub reservoirs_a: Buffer,
+    pub di_reservoirs_a: Buffer,
-    pub reservoirs_b: Buffer,
+    pub di_reservoirs_b: Buffer,
+    pub gi_reservoirs_a: Buffer,
+    pub gi_reservoirs_b: Buffer,
     pub previous_gbuffer: (Texture, TextureView),
     pub previous_depth: (Texture, TextureView),
     pub view_size: UVec2,
@@ -47,18 +52,30 @@ pub fn prepare_solari_lighting_resources(
             continue;
         }
 
-        let size = (view_size.x * view_size.y) as u64 * RESERVOIR_STRUCT_SIZE;
+        let di_reservoirs_a = render_device.create_buffer(&BufferDescriptor {
-
+            label: Some("solari_lighting_di_reservoirs_a"),
-        let reservoirs_a = render_device.create_buffer(&BufferDescriptor {
+            size: (view_size.x * view_size.y) as u64 * DI_RESERVOIR_STRUCT_SIZE,
-            label: Some("solari_lighting_reservoirs_a"),
-            size,
             usage: BufferUsages::STORAGE,
             mapped_at_creation: false,
         });
 
-        let reservoirs_b = render_device.create_buffer(&BufferDescriptor {
+        let di_reservoirs_b = render_device.create_buffer(&BufferDescriptor {
-            label: Some("solari_lighting_reservoirs_b"),
+            label: Some("solari_lighting_di_reservoirs_b"),
-            size,
+            size: (view_size.x * view_size.y) as u64 * DI_RESERVOIR_STRUCT_SIZE,
+            usage: BufferUsages::STORAGE,
+            mapped_at_creation: false,
+        });
+
+        let gi_reservoirs_a = render_device.create_buffer(&BufferDescriptor {
+            label: Some("solari_lighting_gi_reservoirs_a"),
+            size: (view_size.x * view_size.y) as u64 * GI_RESERVOIR_STRUCT_SIZE,
+            usage: BufferUsages::STORAGE,
+            mapped_at_creation: false,
+        });
+
+        let gi_reservoirs_b = render_device.create_buffer(&BufferDescriptor {
+            label: Some("solari_lighting_gi_reservoirs_b"),
+            size: (view_size.x * view_size.y) as u64 * GI_RESERVOIR_STRUCT_SIZE,
             usage: BufferUsages::STORAGE,
             mapped_at_creation: false,
         });
@@ -88,8 +105,10 @@ pub fn prepare_solari_lighting_resources(
         let previous_depth_view = previous_depth.create_view(&TextureViewDescriptor::default());
 
         commands.entity(entity).insert(SolariLightingResources {
-            reservoirs_a,
+            di_reservoirs_a,
-            reservoirs_b,
+            di_reservoirs_b,
+            gi_reservoirs_a,
+            gi_reservoirs_b,
             previous_gbuffer: (previous_gbuffer, previous_gbuffer_view),
             previous_depth: (previous_depth, previous_depth_view),
             view_size,

crates/bevy_solari/src/realtime/restir_di.wgsl

@@ -10,16 +10,16 @@
 #import bevy_solari::sampling::{LightSample, generate_random_light_sample, calculate_light_contribution, trace_light_visibility, sample_disk}
 #import bevy_solari::scene_bindings::{previous_frame_light_id_translations, LIGHT_NOT_PRESENT_THIS_FRAME}
 
-@group(1) @binding(0) var view_output: texture_storage_2d<rgba16float, write>;
+@group(1) @binding(0) var view_output: texture_storage_2d<rgba16float, read_write>;
-@group(1) @binding(1) var<storage, read_write> reservoirs_a: array<Reservoir>;
+@group(1) @binding(1) var<storage, read_write> di_reservoirs_a: array<Reservoir>;
-@group(1) @binding(2) var<storage, read_write> reservoirs_b: array<Reservoir>;
+@group(1) @binding(2) var<storage, read_write> di_reservoirs_b: array<Reservoir>;
-@group(1) @binding(3) var gbuffer: texture_2d<u32>;
+@group(1) @binding(5) var gbuffer: texture_2d<u32>;
-@group(1) @binding(4) var depth_buffer: texture_depth_2d;
+@group(1) @binding(6) var depth_buffer: texture_depth_2d;
-@group(1) @binding(5) var motion_vectors: texture_2d<f32>;
+@group(1) @binding(7) var motion_vectors: texture_2d<f32>;
-@group(1) @binding(6) var previous_gbuffer: texture_2d<u32>;
+@group(1) @binding(8) var previous_gbuffer: texture_2d<u32>;
-@group(1) @binding(7) var previous_depth_buffer: texture_depth_2d;
+@group(1) @binding(9) var previous_depth_buffer: texture_depth_2d;
-@group(1) @binding(8) var<uniform> view: View;
+@group(1) @binding(10) var<uniform> view: View;
-@group(1) @binding(9) var<uniform> previous_view: PreviousViewUniforms;
+@group(1) @binding(11) var<uniform> previous_view: PreviousViewUniforms;
 struct PushConstants { frame_index: u32, reset: u32 }
 var<push_constant> constants: PushConstants;
 
@@ -38,7 +38,7 @@ fn initial_and_temporal(@builtin(global_invocation_id) global_id: vec3<u32>) {
 
     let depth = textureLoad(depth_buffer, global_id.xy, 0);
     if depth == 0.0 {
-        reservoirs_b[pixel_index] = empty_reservoir();
+        di_reservoirs_b[pixel_index] = empty_reservoir();
         return;
     }
     let gpixel = textureLoad(gbuffer, global_id.xy, 0);
@@ -49,9 +49,9 @@ fn initial_and_temporal(@builtin(global_invocation_id) global_id: vec3<u32>) {
 
     let initial_reservoir = generate_initial_reservoir(world_position, world_normal, diffuse_brdf, &rng);
     let temporal_reservoir = load_temporal_reservoir(global_id.xy, depth, world_position, world_normal);
-    let combined_reservoir = merge_reservoirs(initial_reservoir, temporal_reservoir, world_position, world_normal, diffuse_brdf, &rng);
+    let merge_result = merge_reservoirs(initial_reservoir, temporal_reservoir, world_position, world_normal, diffuse_brdf, &rng);
 
-    reservoirs_b[pixel_index] = combined_reservoir.merged_reservoir;
+    di_reservoirs_b[pixel_index] = merge_result.merged_reservoir;
 }
 
 @compute @workgroup_size(8, 8, 1)
@@ -63,7 +63,7 @@ fn spatial_and_shade(@builtin(global_invocation_id) global_id: vec3<u32>) {
 
     let depth = textureLoad(depth_buffer, global_id.xy, 0);
     if depth == 0.0 {
-        reservoirs_a[pixel_index] = empty_reservoir();
+        di_reservoirs_a[pixel_index] = empty_reservoir();
         textureStore(view_output, global_id.xy, vec4(vec3(0.0), 1.0));
         return;
     }
@@ -74,12 +74,12 @@ fn spatial_and_shade(@builtin(global_invocation_id) global_id: vec3<u32>) {
     let diffuse_brdf = base_color / PI;
     let emissive = rgb9e5_to_vec3_(gpixel.g);
 
-    let input_reservoir = reservoirs_b[pixel_index];
+    let input_reservoir = di_reservoirs_b[pixel_index];
     let spatial_reservoir = load_spatial_reservoir(global_id.xy, depth, world_position, world_normal, &rng);
     let merge_result = merge_reservoirs(input_reservoir, spatial_reservoir, world_position, world_normal, diffuse_brdf, &rng);
     let combined_reservoir = merge_result.merged_reservoir;
 
-    reservoirs_a[pixel_index] = combined_reservoir;
+    di_reservoirs_a[pixel_index] = combined_reservoir;
 
     var pixel_color = merge_result.selected_sample_radiance * combined_reservoir.unbiased_contribution_weight * combined_reservoir.visibility;
     pixel_color *= view.exposure;
@@ -112,7 +112,6 @@ fn generate_initial_reservoir(world_position: vec3<f32>, world_normal: vec3<f32>
         reservoir.unbiased_contribution_weight = reservoir.weight_sum * inverse_target_function;
 
         reservoir.visibility = trace_light_visibility(reservoir.sample, world_position);
-        reservoir.unbiased_contribution_weight *= reservoir.visibility;
     }
 
     reservoir.confidence_weight = 1.0;
@@ -123,10 +122,14 @@ fn load_temporal_reservoir(pixel_id: vec2<u32>, depth: f32, world_position: vec3
     let motion_vector = textureLoad(motion_vectors, pixel_id, 0).xy;
     let temporal_pixel_id_float = round(vec2<f32>(pixel_id) - (motion_vector * view.viewport.zw));
     let temporal_pixel_id = vec2<u32>(temporal_pixel_id_float);
+
+    // Check if the current pixel was off screen during the previous frame (current pixel is newly visible),
+    // or if all temporal history should assumed to be invalid
     if any(temporal_pixel_id_float < vec2(0.0)) || any(temporal_pixel_id_float >= view.viewport.zw) || bool(constants.reset) {
         return empty_reservoir();
     }
 
+    // Check if the pixel features have changed heavily between the current and previous frame
     let temporal_depth = textureLoad(previous_depth_buffer, temporal_pixel_id, 0);
     let temporal_gpixel = textureLoad(previous_gbuffer, temporal_pixel_id, 0);
     let temporal_world_position = reconstruct_previous_world_position(temporal_pixel_id, temporal_depth);
@@ -136,8 +139,9 @@ fn load_temporal_reservoir(pixel_id: vec2<u32>, depth: f32, world_position: vec3
     }
 
     let temporal_pixel_index = temporal_pixel_id.x + temporal_pixel_id.y * u32(view.viewport.z);
-    var temporal_reservoir = reservoirs_a[temporal_pixel_index];
+    var temporal_reservoir = di_reservoirs_a[temporal_pixel_index];
 
+    // Check if the light selected in the previous frame no longer exists in the current frame (e.g. entity despawned)
     temporal_reservoir.sample.light_id.x = previous_frame_light_id_translations[temporal_reservoir.sample.light_id.x];
     if temporal_reservoir.sample.light_id.x == LIGHT_NOT_PRESENT_THIS_FRAME {
         return empty_reservoir();
@@ -160,7 +164,7 @@ fn load_spatial_reservoir(pixel_id: vec2<u32>, depth: f32, world_position: vec3<
     }
 
     let spatial_pixel_index = spatial_pixel_id.x + spatial_pixel_id.y * u32(view.viewport.z);
-    var spatial_reservoir = reservoirs_b[spatial_pixel_index];
+    var spatial_reservoir = di_reservoirs_b[spatial_pixel_index];
 
     if reservoir_valid(spatial_reservoir) {
         spatial_reservoir.visibility = trace_light_visibility(spatial_reservoir.sample, world_position);
@@ -170,8 +174,8 @@ fn load_spatial_reservoir(pixel_id: vec2<u32>, depth: f32, world_position: vec3<
 }
 
 fn get_neighbor_pixel_id(center_pixel_id: vec2<u32>, rng: ptr<function, u32>) -> vec2<u32> {
-    var spatial_id = vec2<i32>(center_pixel_id) + vec2<i32>(sample_disk(SPATIAL_REUSE_RADIUS_PIXELS, rng));
+    var spatial_id = vec2<f32>(center_pixel_id) + sample_disk(SPATIAL_REUSE_RADIUS_PIXELS, rng);
-    spatial_id = clamp(spatial_id, vec2(0i), vec2<i32>(view.viewport.zw) - 1i);
+    spatial_id = clamp(spatial_id, vec2(0.0), view.viewport.zw - 1.0);
     return vec2<u32>(spatial_id);
 }
 
@@ -209,7 +213,7 @@ fn depth_ndc_to_view_z(ndc_depth: f32) -> f32 {
 #endif
 }
 
-// Don't adjust the size of this struct without also adjusting RESERVOIR_STRUCT_SIZE.
+// Don't adjust the size of this struct without also adjusting DI_RESERVOIR_STRUCT_SIZE.
 struct Reservoir {
     sample: LightSample,
     weight_sum: f32,
@@ -283,7 +287,7 @@ fn merge_reservoirs(
 
 fn reservoir_target_function(reservoir: Reservoir, world_position: vec3<f32>, world_normal: vec3<f32>, diffuse_brdf: vec3<f32>) -> vec4<f32> {
     if !reservoir_valid(reservoir) { return vec4(0.0); }
-    let light_contribution = calculate_light_contribution(reservoir.sample, world_position, world_normal).radiance;
+    let light_contribution = calculate_light_contribution(reservoir.sample, world_position, world_normal).radiance * reservoir.visibility;
     let target_function = luminance(light_contribution * diffuse_brdf);
     return vec4(light_contribution, target_function);
 }

crates/bevy_solari/src/realtime/restir_gi.wgsl

@@ -0,0 +1,310 @@
+// https://intro-to-restir.cwyman.org/presentations/2023ReSTIR_Course_Notes.pdf
+
+#import bevy_core_pipeline::tonemapping::tonemapping_luminance as luminance
+#import bevy_pbr::pbr_deferred_types::unpack_24bit_normal
+#import bevy_pbr::prepass_bindings::PreviousViewUniforms
+#import bevy_pbr::rgb9e5::rgb9e5_to_vec3_
+#import bevy_pbr::utils::{rand_f, octahedral_decode}
+#import bevy_render::maths::{PI, PI_2}
+#import bevy_render::view::View
+#import bevy_solari::sampling::{sample_uniform_hemisphere, sample_random_light, sample_disk, trace_point_visibility}
+#import bevy_solari::scene_bindings::{trace_ray, resolve_ray_hit_full, RAY_T_MIN, RAY_T_MAX}
+
+@group(1) @binding(0) var view_output: texture_storage_2d<rgba16float, read_write>;
+@group(1) @binding(3) var<storage, read_write> gi_reservoirs_a: array<Reservoir>;
+@group(1) @binding(4) var<storage, read_write> gi_reservoirs_b: array<Reservoir>;
+@group(1) @binding(5) var gbuffer: texture_2d<u32>;
+@group(1) @binding(6) var depth_buffer: texture_depth_2d;
+@group(1) @binding(7) var motion_vectors: texture_2d<f32>;
+@group(1) @binding(8) var previous_gbuffer: texture_2d<u32>;
+@group(1) @binding(9) var previous_depth_buffer: texture_depth_2d;
+@group(1) @binding(10) var<uniform> view: View;
+@group(1) @binding(11) var<uniform> previous_view: PreviousViewUniforms;
+struct PushConstants { frame_index: u32, reset: u32 }
+var<push_constant> constants: PushConstants;
+
+const SPATIAL_REUSE_RADIUS_PIXELS = 30.0;
+const CONFIDENCE_WEIGHT_CAP = 30.0;
+
+@compute @workgroup_size(8, 8, 1)
+fn initial_and_temporal(@builtin(global_invocation_id) global_id: vec3<u32>) {
+    if any(global_id.xy >= vec2u(view.viewport.zw)) { return; }
+
+    let pixel_index = global_id.x + global_id.y * u32(view.viewport.z);
+    var rng = pixel_index + constants.frame_index;
+
+    let depth = textureLoad(depth_buffer, global_id.xy, 0);
+    if depth == 0.0 {
+        gi_reservoirs_b[pixel_index] = empty_reservoir();
+        return;
+    }
+    let gpixel = textureLoad(gbuffer, global_id.xy, 0);
+    let world_position = reconstruct_world_position(global_id.xy, depth);
+    let world_normal = octahedral_decode(unpack_24bit_normal(gpixel.a));
+
+    let initial_reservoir = generate_initial_reservoir(world_position, world_normal, &rng);
+    let temporal_reservoir = load_temporal_reservoir(global_id.xy, depth, world_position, world_normal);
+    let merge_result = merge_reservoirs(initial_reservoir, temporal_reservoir, vec3(1.0), vec3(1.0), &rng);
+
+    gi_reservoirs_b[pixel_index] = merge_result.merged_reservoir;
+}
+
+@compute @workgroup_size(8, 8, 1)
+fn spatial_and_shade(@builtin(global_invocation_id) global_id: vec3<u32>) {
+    if any(global_id.xy >= vec2u(view.viewport.zw)) { return; }
+
+    let pixel_index = global_id.x + global_id.y * u32(view.viewport.z);
+    var rng = pixel_index + constants.frame_index;
+
+    let depth = textureLoad(depth_buffer, global_id.xy, 0);
+    if depth == 0.0 {
+        gi_reservoirs_a[pixel_index] = empty_reservoir();
+        return;
+    }
+    let gpixel = textureLoad(gbuffer, global_id.xy, 0);
+    let world_position = reconstruct_world_position(global_id.xy, depth);
+    let world_normal = octahedral_decode(unpack_24bit_normal(gpixel.a));
+    let base_color = pow(unpack4x8unorm(gpixel.r).rgb, vec3(2.2));
+    let diffuse_brdf = base_color / PI;
+
+    let input_reservoir = gi_reservoirs_b[pixel_index];
+    let spatial_reservoir = load_spatial_reservoir(global_id.xy, depth, world_position, world_normal, &rng);
+
+    let input_factor = dot(normalize(input_reservoir.sample_point_world_position - world_position), world_normal) * diffuse_brdf;
+    let spatial_factor = dot(normalize(spatial_reservoir.sample_point_world_position - world_position), world_normal) * diffuse_brdf;
+
+    let merge_result = merge_reservoirs(input_reservoir, spatial_reservoir, input_factor, spatial_factor, &rng);
+    let combined_reservoir = merge_result.merged_reservoir;
+
+    gi_reservoirs_a[pixel_index] = combined_reservoir;
+
+    var pixel_color = textureLoad(view_output, global_id.xy);
+    pixel_color += vec4(merge_result.selected_sample_radiance * combined_reservoir.unbiased_contribution_weight * view.exposure, 0.0);
+    textureStore(view_output, global_id.xy, pixel_color);
+}
+
+fn generate_initial_reservoir(world_position: vec3<f32>, world_normal: vec3<f32>, rng: ptr<function, u32>) -> Reservoir{
+    var reservoir = empty_reservoir();
+
+    let ray_direction = sample_uniform_hemisphere(world_normal, rng);
+    let ray_hit = trace_ray(world_position, ray_direction, RAY_T_MIN, RAY_T_MAX, RAY_FLAG_NONE);
+
+    if ray_hit.kind == RAY_QUERY_INTERSECTION_NONE {
+        return reservoir;
+    }
+
+    let sample_point = resolve_ray_hit_full(ray_hit);
+
+    if all(sample_point.material.emissive != vec3(0.0)) {
+        return reservoir;
+    }
+
+    reservoir.sample_point_world_position = sample_point.world_position;
+    reservoir.sample_point_world_normal = sample_point.world_normal;
+    reservoir.confidence_weight = 1.0;
+
+    let sample_point_diffuse_brdf = sample_point.material.base_color / PI;
+    let direct_lighting = sample_random_light(sample_point.world_position, sample_point.world_normal, rng);
+    reservoir.radiance = direct_lighting.radiance * sample_point_diffuse_brdf;
+
+    let inverse_uniform_hemisphere_pdf = PI_2;
+    reservoir.unbiased_contribution_weight = direct_lighting.inverse_pdf * inverse_uniform_hemisphere_pdf;
+
+    return reservoir;
+}
+
+fn load_temporal_reservoir(pixel_id: vec2<u32>, depth: f32, world_position: vec3<f32>, world_normal: vec3<f32>) -> Reservoir {
+    let motion_vector = textureLoad(motion_vectors, pixel_id, 0).xy;
+    let temporal_pixel_id_float = round(vec2<f32>(pixel_id) - (motion_vector * view.viewport.zw));
+    let temporal_pixel_id = vec2<u32>(temporal_pixel_id_float);
+
+    // Check if the current pixel was off screen during the previous frame (current pixel is newly visible),
+    // or if all temporal history should assumed to be invalid
+    if any(temporal_pixel_id_float < vec2(0.0)) || any(temporal_pixel_id_float >= view.viewport.zw) || bool(constants.reset) {
+        return empty_reservoir();
+    }
+
+    // Check if the pixel features have changed heavily between the current and previous frame
+    let temporal_depth = textureLoad(previous_depth_buffer, temporal_pixel_id, 0);
+    let temporal_gpixel = textureLoad(previous_gbuffer, temporal_pixel_id, 0);
+    let temporal_world_position = reconstruct_previous_world_position(temporal_pixel_id, temporal_depth);
+    let temporal_world_normal = octahedral_decode(unpack_24bit_normal(temporal_gpixel.a));
+    if pixel_dissimilar(depth, world_position, temporal_world_position, world_normal, temporal_world_normal) {
+        return empty_reservoir();
+    }
+
+    let temporal_pixel_index = temporal_pixel_id.x + temporal_pixel_id.y * u32(view.viewport.z);
+    var temporal_reservoir = gi_reservoirs_a[temporal_pixel_index];
+
+    temporal_reservoir.confidence_weight = min(temporal_reservoir.confidence_weight, CONFIDENCE_WEIGHT_CAP);
+
+    return temporal_reservoir;
+}
+
+fn load_spatial_reservoir(pixel_id: vec2<u32>, depth: f32, world_position: vec3<f32>, world_normal: vec3<f32>, rng: ptr<function, u32>) -> Reservoir {
+    let spatial_pixel_id = get_neighbor_pixel_id(pixel_id, rng);
+
+    let spatial_depth = textureLoad(depth_buffer, spatial_pixel_id, 0);
+    let spatial_gpixel = textureLoad(gbuffer, spatial_pixel_id, 0);
+    let spatial_world_position = reconstruct_world_position(spatial_pixel_id, spatial_depth);
+    let spatial_world_normal = octahedral_decode(unpack_24bit_normal(spatial_gpixel.a));
+    if pixel_dissimilar(depth, world_position, spatial_world_position, world_normal, spatial_world_normal) {
+        return empty_reservoir();
+    }
+
+    let spatial_pixel_index = spatial_pixel_id.x + spatial_pixel_id.y * u32(view.viewport.z);
+    var spatial_reservoir = gi_reservoirs_b[spatial_pixel_index];
+
+    var jacobian = jacobian(
+        world_position,
+        spatial_world_position,
+        spatial_reservoir.sample_point_world_position,
+        spatial_reservoir.sample_point_world_normal
+    );
+    if jacobian > 10.0 || jacobian < 0.1 {
+        return empty_reservoir();
+    }
+    spatial_reservoir.unbiased_contribution_weight *= jacobian;
+
+    spatial_reservoir.unbiased_contribution_weight *= trace_point_visibility(world_position, spatial_reservoir.sample_point_world_position);
+
+    return spatial_reservoir;
+}
+
+fn get_neighbor_pixel_id(center_pixel_id: vec2<u32>, rng: ptr<function, u32>) -> vec2<u32> {
+    var spatial_id = vec2<f32>(center_pixel_id) + sample_disk(SPATIAL_REUSE_RADIUS_PIXELS, rng);
+    spatial_id = clamp(spatial_id, vec2(0.0), view.viewport.zw - 1.0);
+    return vec2<u32>(spatial_id);
+}
+
+fn jacobian(
+    world_position: vec3<f32>,
+    spatial_world_position: vec3<f32>,
+    sample_point_world_position: vec3<f32>,
+    sample_point_world_normal: vec3<f32>,
+) -> f32 {
+    let r = world_position - sample_point_world_position;
+    let q = spatial_world_position - sample_point_world_position;
+    let rl = length(r);
+    let ql = length(q);
+    let phi_r = saturate(dot(r / rl, sample_point_world_normal));
+    let phi_q = saturate(dot(q / ql, sample_point_world_normal));
+    let jacobian = (phi_r * ql * ql) / (phi_q * rl * rl);
+    return select(jacobian, 0.0, isinf(jacobian) || isnan(jacobian));
+}
+
+fn isinf(x: f32) -> bool {
+    return (bitcast<u32>(x) & 0x7fffffffu) == 0x7f800000u;
+}
+
+fn isnan(x: f32) -> bool {
+    return (bitcast<u32>(x) & 0x7fffffffu) > 0x7f800000u;
+}
+
+fn reconstruct_world_position(pixel_id: vec2<u32>, depth: f32) -> vec3<f32> {
+    let uv = (vec2<f32>(pixel_id) + 0.5) / view.viewport.zw;
+    let xy_ndc = (uv - vec2(0.5)) * vec2(2.0, -2.0);
+    let world_pos = view.world_from_clip * vec4(xy_ndc, depth, 1.0);
+    return world_pos.xyz / world_pos.w;
+}
+
+fn reconstruct_previous_world_position(pixel_id: vec2<u32>, depth: f32) -> vec3<f32> {
+    let uv = (vec2<f32>(pixel_id) + 0.5) / view.viewport.zw;
+    let xy_ndc = (uv - vec2(0.5)) * vec2(2.0, -2.0);
+    let world_pos = previous_view.world_from_clip * vec4(xy_ndc, depth, 1.0);
+    return world_pos.xyz / world_pos.w;
+}
+
+// Reject if tangent plane difference difference more than 0.3% or angle between normals more than 25 degrees
+fn pixel_dissimilar(depth: f32, world_position: vec3<f32>, other_world_position: vec3<f32>, normal: vec3<f32>, other_normal: vec3<f32>) -> bool {
+    // https://developer.download.nvidia.com/video/gputechconf/gtc/2020/presentations/s22699-fast-denoising-with-self-stabilizing-recurrent-blurs.pdf#page=45
+    let tangent_plane_distance = abs(dot(normal, other_world_position - world_position));
+    let view_z = -depth_ndc_to_view_z(depth);
+
+    return tangent_plane_distance / view_z > 0.003 || dot(normal, other_normal) < 0.906;
+}
+
+fn depth_ndc_to_view_z(ndc_depth: f32) -> f32 {
+#ifdef VIEW_PROJECTION_PERSPECTIVE
+    return -view.clip_from_view[3][2]() / ndc_depth;
+#else ifdef VIEW_PROJECTION_ORTHOGRAPHIC
+    return -(view.clip_from_view[3][2] - ndc_depth) / view.clip_from_view[2][2];
+#else
+    let view_pos = view.view_from_clip * vec4(0.0, 0.0, ndc_depth, 1.0);
+    return view_pos.z / view_pos.w;
+#endif
+}
+
+// Don't adjust the size of this struct without also adjusting GI_RESERVOIR_STRUCT_SIZE.
+struct Reservoir {
+    sample_point_world_position: vec3<f32>,
+    weight_sum: f32,
+    radiance: vec3<f32>,
+    confidence_weight: f32,
+    sample_point_world_normal: vec3<f32>,
+    unbiased_contribution_weight: f32,
+}
+
+fn empty_reservoir() -> Reservoir {
+    return Reservoir(
+        vec3(0.0),
+        0.0,
+        vec3(0.0),
+        0.0,
+        vec3(0.0),
+        0.0,
+    );
+}
+
+struct ReservoirMergeResult {
+    merged_reservoir: Reservoir,
+    selected_sample_radiance: vec3<f32>,
+}
+
+fn merge_reservoirs(
+    canonical_reservoir: Reservoir,
+    other_reservoir: Reservoir,
+    canonical_factor: vec3<f32>,
+    other_factor: vec3<f32>,
+    rng: ptr<function, u32>,
+) -> ReservoirMergeResult {
+    var combined_reservoir = empty_reservoir();
+    combined_reservoir.confidence_weight = canonical_reservoir.confidence_weight + other_reservoir.confidence_weight;
+
+    if combined_reservoir.confidence_weight == 0.0 { return ReservoirMergeResult(combined_reservoir, vec3(0.0)); }
+
+    // TODO: Balance heuristic MIS weights
+    let mis_weight_denominator = 1.0 / combined_reservoir.confidence_weight;
+
+    let canonical_mis_weight = canonical_reservoir.confidence_weight * mis_weight_denominator;
+    let canonical_radiance = canonical_reservoir.radiance * canonical_factor;
+    let canonical_target_function = luminance(canonical_radiance);
+    let canonical_resampling_weight = canonical_mis_weight * (canonical_target_function * canonical_reservoir.unbiased_contribution_weight);
+
+    let other_mis_weight = other_reservoir.confidence_weight * mis_weight_denominator;
+    let other_radiance = other_reservoir.radiance * other_factor;
+    let other_target_function = luminance(other_radiance);
+    let other_resampling_weight = other_mis_weight * (other_target_function * other_reservoir.unbiased_contribution_weight);
+
+    combined_reservoir.weight_sum = canonical_resampling_weight + other_resampling_weight;
+
+    if rand_f(rng) < other_resampling_weight / combined_reservoir.weight_sum {
+        combined_reservoir.sample_point_world_position = other_reservoir.sample_point_world_position;
+        combined_reservoir.sample_point_world_normal = other_reservoir.sample_point_world_normal;
+        combined_reservoir.radiance = other_reservoir.radiance;
+
+        let inverse_target_function = select(0.0, 1.0 / other_target_function, other_target_function > 0.0);
+        combined_reservoir.unbiased_contribution_weight = combined_reservoir.weight_sum * inverse_target_function;
+
+        return ReservoirMergeResult(combined_reservoir, other_radiance);
+    } else {
+        combined_reservoir.sample_point_world_position = canonical_reservoir.sample_point_world_position;
+        combined_reservoir.sample_point_world_normal = canonical_reservoir.sample_point_world_normal;
+        combined_reservoir.radiance = canonical_reservoir.radiance;
+
+        let inverse_target_function = select(0.0, 1.0 / canonical_target_function, canonical_target_function > 0.0);
+        combined_reservoir.unbiased_contribution_weight = combined_reservoir.weight_sum * inverse_target_function;
+
+        return ReservoirMergeResult(combined_reservoir, canonical_radiance);
+    }
+}

crates/bevy_solari/src/scene/sampling.wgsl

@@ -15,6 +15,17 @@ fn sample_cosine_hemisphere(normal: vec3<f32>, rng: ptr<function, u32>) -> vec3<
     return vec3(x, y, z);
 }
 
+// https://www.pbr-book.org/3ed-2018/Monte_Carlo_Integration/2D_Sampling_with_Multidimensional_Transformations#UniformlySamplingaHemisphere
+fn sample_uniform_hemisphere(normal: vec3<f32>, rng: ptr<function, u32>) -> vec3<f32> {
+    let cos_theta = rand_f(rng);
+    let phi = PI_2 * rand_f(rng);
+    let sin_theta = sqrt(max(1.0 - cos_theta * cos_theta, 0.0));
+    let x = sin_theta * cos(phi);
+    let y = sin_theta * sin(phi);
+    let z = cos_theta;
+    return build_orthonormal_basis(normal) * vec3(x, y, z);
+}
+
 // https://www.realtimerendering.com/raytracinggems/unofficial_RayTracingGems_v1.9.pdf#0004286901.INDD%3ASec19%3A294
 fn sample_disk(disk_radius: f32, rng: ptr<function, u32>) -> vec2<f32> {
     let ab = 2.0 * rand_vec2f(rng) - 1.0;
@@ -37,11 +48,16 @@ fn sample_disk(disk_radius: f32, rng: ptr<function, u32>) -> vec2<f32> {
     return vec2(x, y);
 }
 
-fn sample_random_light(ray_origin: vec3<f32>, origin_world_normal: vec3<f32>, rng: ptr<function, u32>) -> vec3<f32> {
+struct SampleRandomLightResult {
+    radiance: vec3<f32>,
+    inverse_pdf: f32,
+}
+
+fn sample_random_light(ray_origin: vec3<f32>, origin_world_normal: vec3<f32>, rng: ptr<function, u32>) -> SampleRandomLightResult {
     let light_sample = generate_random_light_sample(rng);
     let light_contribution = calculate_light_contribution(light_sample, ray_origin, origin_world_normal);
     let visibility = trace_light_visibility(light_sample, ray_origin);
-    return light_contribution.radiance * visibility * light_contribution.inverse_pdf;
+    return SampleRandomLightResult(light_contribution.radiance * visibility, light_contribution.inverse_pdf);
 }
 
 struct LightSample {
@@ -171,10 +187,15 @@ fn trace_emissive_mesh_visibility(light_sample: LightSample, instance_id: u32, r
 
     let triangle_data = resolve_triangle_data_full(instance_id, triangle_id, barycentrics);
 
-    let light_distance = distance(ray_origin, triangle_data.world_position);
+    return trace_point_visibility(ray_origin, triangle_data.world_position);
-    let ray_direction = (triangle_data.world_position - ray_origin) / light_distance;
+}
 
-    let ray_t_max = light_distance - RAY_T_MIN - RAY_T_MIN;
+fn trace_point_visibility(ray_origin: vec3<f32>, point: vec3<f32>) -> f32 {
+    let ray = point - ray_origin;
+    let dist = length(ray);
+    let ray_direction = ray / dist;
+
+    let ray_t_max = dist - RAY_T_MIN - RAY_T_MIN;
     if ray_t_max < RAY_T_MIN { return 0.0; }
 
     let ray_hit = trace_ray(ray_origin, ray_direction, RAY_T_MIN, ray_t_max, RAY_FLAG_TERMINATE_ON_FIRST_HIT);

crates/bevy_solari/src/scene/types.rs

@@ -10,8 +10,8 @@ use derive_more::derive::From;
 
 /// A mesh component used for raytracing.
 ///
-/// The mesh used in this component must have [`bevy_render::mesh::Mesh::enable_raytracing`] set to true,
+/// The mesh used in this component must have [`Mesh::enable_raytracing`] set to true,
-/// use the following set of vertex attributes: `{POSITION, NORMAL, UV_0, TANGENT}`, use [`bevy_render::render_resource::PrimitiveTopology::TriangleList`],
+/// use the following set of vertex attributes: `{POSITION, NORMAL, UV_0, TANGENT}`, use [`bevy_mesh::PrimitiveTopology::TriangleList`],
 /// and use [`bevy_mesh::Indices::U32`].
 ///
 /// The material used for this entity must be [`MeshMaterial3d<StandardMaterial>`].

crates/bevy_ui/src/focus.rs

@@ -267,7 +267,9 @@ pub fn ui_focus_system(
             // Save the relative cursor position to the correct component
             if let Some(mut node_relative_cursor_position_component) = node.relative_cursor_position
             {
-                *node_relative_cursor_position_component = relative_cursor_position_component;
+                // Avoid triggering change detection when not necessary.
+                node_relative_cursor_position_component
+                    .set_if_neq(relative_cursor_position_component);
             }
 
             if contains_cursor {

examples/diagnostics/log_diagnostics.rs

@@ -33,7 +33,7 @@ fn main() {
             // Adds frame time, FPS and frame count diagnostics.
             FrameTimeDiagnosticsPlugin::default(),
             // Adds an entity count diagnostic.
-            EntityCountDiagnosticsPlugin,
+            EntityCountDiagnosticsPlugin::default(),
             // Adds cpu and memory usage diagnostics for systems and the entire game process.
             SystemInformationDiagnosticsPlugin,
             // Forwards various diagnostics from the render app to the main app.

examples/ui/core_widgets.rs

@@ -3,9 +3,9 @@
 use bevy::{
     color::palettes::basic::*,
     core_widgets::{
-        Callback, CoreButton, CoreCheckbox, CoreRadio, CoreRadioGroup, CoreSlider,
+        Activate, Callback, CoreButton, CoreCheckbox, CoreRadio, CoreRadioGroup, CoreSlider,
         CoreSliderDragState, CoreSliderThumb, CoreWidgetsPlugins, SliderRange, SliderValue,
-        TrackClick,
+        TrackClick, ValueChange,
     },
     input_focus::{
         tab_navigation::{TabGroup, TabIndex, TabNavigationPlugin},
@@ -120,24 +120,24 @@ fn update_widget_values(
 
 fn setup(mut commands: Commands, assets: Res<AssetServer>) {
     // System to print a value when the button is clicked.
-    let on_click = commands.register_system(|| {
+    let on_click = commands.register_system(|_: In<Activate>| {
         info!("Button clicked!");
     });
 
     // System to update a resource when the slider value changes. Note that we could have
     // updated the slider value directly, but we want to demonstrate externalizing the state.
     let on_change_value = commands.register_system(
-        |value: In<f32>, mut widget_states: ResMut<DemoWidgetStates>| {
+        |value: In<ValueChange<f32>>, mut widget_states: ResMut<DemoWidgetStates>| {
-            widget_states.slider_value = *value;
+            widget_states.slider_value = value.0.value;
         },
     );
 
     // System to update a resource when the radio group changes.
     let on_change_radio = commands.register_system(
-        |value: In<Entity>,
+        |value: In<Activate>,
          mut widget_states: ResMut<DemoWidgetStates>,
          q_radios: Query<&DemoRadio>| {
-            if let Ok(radio) = q_radios.get(*value) {
+            if let Ok(radio) = q_radios.get(value.0 .0) {
                 widget_states.slider_click = radio.0;
             }
         },
@@ -155,9 +155,9 @@ fn setup(mut commands: Commands, assets: Res<AssetServer>) {
 
 fn demo_root(
     asset_server: &AssetServer,
-    on_click: Callback,
+    on_click: Callback<In<Activate>>,
-    on_change_value: Callback<In<f32>>,
+    on_change_value: Callback<In<ValueChange<f32>>>,
-    on_change_radio: Callback<In<Entity>>,
+    on_change_radio: Callback<In<Activate>>,
 ) -> impl Bundle {
     (
         Node {
@@ -181,7 +181,7 @@ fn demo_root(
     )
 }
 
-fn button(asset_server: &AssetServer, on_click: Callback) -> impl Bundle {
+fn button(asset_server: &AssetServer, on_click: Callback<In<Activate>>) -> impl Bundle {
     (
         Node {
             width: Val::Px(150.0),
@@ -324,7 +324,12 @@ fn set_button_style(
 }
 
 /// Create a demo slider
-fn slider(min: f32, max: f32, value: f32, on_change: Callback<In<f32>>) -> impl Bundle {
+fn slider(
+    min: f32,
+    max: f32,
+    value: f32,
+    on_change: Callback<In<ValueChange<f32>>>,
+) -> impl Bundle {
     (
         Node {
             display: Display::Flex,
@@ -469,7 +474,7 @@ fn thumb_color(disabled: bool, hovered: bool) -> Color {
 fn checkbox(
     asset_server: &AssetServer,
     caption: &str,
-    on_change: Callback<In<bool>>,
+    on_change: Callback<In<ValueChange<bool>>>,
 ) -> impl Bundle {
     (
         Node {
@@ -662,7 +667,7 @@ fn set_checkbox_or_radio_style(
 }
 
 /// Create a demo radio group
-fn radio_group(asset_server: &AssetServer, on_change: Callback<In<Entity>>) -> impl Bundle {
+fn radio_group(asset_server: &AssetServer, on_change: Callback<In<Activate>>) -> impl Bundle {
     (
         Node {
             display: Display::Flex,

examples/ui/core_widgets_observers.rs

@@ -3,8 +3,8 @@
 use bevy::{
     color::palettes::basic::*,
     core_widgets::{
-        Callback, CoreButton, CoreCheckbox, CoreSlider, CoreSliderThumb, CoreWidgetsPlugins,
+        Activate, Callback, CoreButton, CoreCheckbox, CoreSlider, CoreSliderThumb,
-        SliderRange, SliderValue,
+        CoreWidgetsPlugins, SliderRange, SliderValue, ValueChange,
     },
     ecs::system::SystemId,
     input_focus::{
@@ -85,15 +85,15 @@ struct DemoWidgetStates {
 
 fn setup(mut commands: Commands, assets: Res<AssetServer>) {
     // System to print a value when the button is clicked.
-    let on_click = commands.register_system(|| {
+    let on_click = commands.register_system(|_: In<Activate>| {
         info!("Button clicked!");
     });
 
     // System to update a resource when the slider value changes. Note that we could have
     // updated the slider value directly, but we want to demonstrate externalizing the state.
     let on_change_value = commands.register_system(
-        |value: In<f32>, mut widget_states: ResMut<DemoWidgetStates>| {
+        |value: In<ValueChange<f32>>, mut widget_states: ResMut<DemoWidgetStates>| {
-            widget_states.slider_value = *value;
+            widget_states.slider_value = value.0.value;
         },
     );
 
@@ -104,8 +104,8 @@ fn setup(mut commands: Commands, assets: Res<AssetServer>) {
 
 fn demo_root(
     asset_server: &AssetServer,
-    on_click: SystemId,
+    on_click: SystemId<In<Activate>>,
-    on_change_value: SystemId<In<f32>>,
+    on_change_value: SystemId<In<ValueChange<f32>>>,
 ) -> impl Bundle {
     (
         Node {
@@ -128,7 +128,7 @@ fn demo_root(
     )
 }
 
-fn button(asset_server: &AssetServer, on_click: Callback) -> impl Bundle {
+fn button(asset_server: &AssetServer, on_click: Callback<In<Activate>>) -> impl Bundle {
     (
         Node {
             width: Val::Px(150.0),
@@ -351,7 +351,12 @@ fn set_button_style(
 }
 
 /// Create a demo slider
-fn slider(min: f32, max: f32, value: f32, on_change: Callback<In<f32>>) -> impl Bundle {
+fn slider(
+    min: f32,
+    max: f32,
+    value: f32,
+    on_change: Callback<In<ValueChange<f32>>>,
+) -> impl Bundle {
     (
         Node {
             display: Display::Flex,
@@ -517,7 +522,7 @@ fn thumb_color(disabled: bool, hovered: bool) -> Color {
 fn checkbox(
     asset_server: &AssetServer,
     caption: &str,
-    on_change: Callback<In<bool>>,
+    on_change: Callback<In<ValueChange<bool>>>,
 ) -> impl Bundle {
     (
         Node {

examples/ui/feathers.rs

@@ -2,7 +2,8 @@
 
 use bevy::{
     core_widgets::{
-        Callback, CoreRadio, CoreRadioGroup, CoreWidgetsPlugins, SliderPrecision, SliderStep,
+        Activate, Callback, CoreRadio, CoreRadioGroup, CoreWidgetsPlugins, SliderPrecision,
+        SliderStep,
     },
     feathers::{
         controls::{
@@ -49,9 +50,9 @@ fn setup(mut commands: Commands) {
 fn demo_root(commands: &mut Commands) -> impl Bundle {
     // Update radio button states based on notification from radio group.
     let radio_exclusion = commands.register_system(
-        |ent: In<Entity>, q_radio: Query<Entity, With<CoreRadio>>, mut commands: Commands| {
+        |ent: In<Activate>, q_radio: Query<Entity, With<CoreRadio>>, mut commands: Commands| {
             for radio in q_radio.iter() {
-                if radio == *ent {
+                if radio == ent.0 .0 {
                     commands.entity(radio).insert(Checked);
                 } else {
                     commands.entity(radio).remove::<Checked>();
@@ -98,9 +99,11 @@ fn demo_root(commands: &mut Commands) -> impl Bundle {
                     children![
                         button(
                             ButtonProps {
-                                on_click: Callback::System(commands.register_system(|| {
+                                on_click: Callback::System(commands.register_system(
+                                    |_: In<Activate>| {
                                         info!("Normal button clicked!");
-                                })),
+                                    }
+                                )),
                                 ..default()
                             },
                             (),
@@ -108,9 +111,11 @@ fn demo_root(commands: &mut Commands) -> impl Bundle {
                         ),
                         button(
                             ButtonProps {
-                                on_click: Callback::System(commands.register_system(|| {
+                                on_click: Callback::System(commands.register_system(
+                                    |_: In<Activate>| {
                                         info!("Disabled button clicked!");
-                                })),
+                                    }
+                                )),
                                 ..default()
                             },
                             InteractionDisabled,
@@ -118,9 +123,11 @@ fn demo_root(commands: &mut Commands) -> impl Bundle {
                         ),
                         button(
                             ButtonProps {
-                                on_click: Callback::System(commands.register_system(|| {
+                                on_click: Callback::System(commands.register_system(
+                                    |_: In<Activate>| {
                                         info!("Primary button clicked!");
-                                })),
+                                    }
+                                )),
                                 variant: ButtonVariant::Primary,
                                 ..default()
                             },
@@ -141,9 +148,11 @@ fn demo_root(commands: &mut Commands) -> impl Bundle {
                     children![
                         button(
                             ButtonProps {
-                                on_click: Callback::System(commands.register_system(|| {
+                                on_click: Callback::System(commands.register_system(
+                                    |_: In<Activate>| {
                                         info!("Left button clicked!");
-                                })),
+                                    }
+                                )),
                                 corners: RoundedCorners::Left,
                                 ..default()
                             },
@@ -152,9 +161,11 @@ fn demo_root(commands: &mut Commands) -> impl Bundle {
                         ),
                         button(
                             ButtonProps {
-                                on_click: Callback::System(commands.register_system(|| {
+                                on_click: Callback::System(commands.register_system(
+                                    |_: In<Activate>| {
                                         info!("Center button clicked!");
-                                })),
+                                    }
+                                )),
                                 corners: RoundedCorners::None,
                                 ..default()
                             },
@@ -163,9 +174,11 @@ fn demo_root(commands: &mut Commands) -> impl Bundle {
                         ),
                         button(
                             ButtonProps {
-                                on_click: Callback::System(commands.register_system(|| {
+                                on_click: Callback::System(commands.register_system(
+                                    |_: In<Activate>| {
                                         info!("Right button clicked!");
-                                })),
+                                    }
+                                )),
                                 variant: ButtonVariant::Primary,
                                 corners: RoundedCorners::Right,
                             },
@@ -176,7 +189,7 @@ fn demo_root(commands: &mut Commands) -> impl Bundle {
                 ),
                 button(
                     ButtonProps {
-                        on_click: Callback::System(commands.register_system(|| {
+                        on_click: Callback::System(commands.register_system(|_: In<Activate>| {
                             info!("Wide button clicked!");
                         })),
                         ..default()

release-content/release-notes/bevy_solari.md

@@ -1,7 +1,7 @@
 ---
 title: Initial raytraced lighting progress (bevy_solari)
 authors: ["@JMS55"]
-pull_requests: [19058, 19620, 19790]
+pull_requests: [19058, 19620, 19790, 20020, 20113]
 ---
 
 (TODO: Embed solari example screenshot here)
@@ -19,13 +19,13 @@ In Bevy, direct lighting comes from analytical light components (`DirectionalLig
 The problem with these methods is that they all have large downsides:
 
 * Emissive meshes do not cast light onto other objects, either direct or indirect.
-* Shadow maps are very expensive to render and consume a lot of memory, so you're limited to using only a few shadow casting lights. Good quality can be difficult to obtain in large scenes.
+* Shadow maps are very expensive to render and consume a lot of memory, so you're limited to using only a few shadow casting lights. Good shadow quality can be difficult to obtain in large scenes.
 * Baked lighting does not update in realtime as objects and lights move around, is low resolution/quality, and requires time to bake, slowing down game production.
 * Screen-space methods have low quality and do not capture off-screen geometry and light.
 
 Bevy Solari is intended as a completely alternate, high-end lighting solution for Bevy that uses GPU-accelerated raytracing to fix all of the above problems. Emissive meshes will properly cast light and shadows, you will be able to have hundreds of shadow casting lights, quality will be much better, it will require no baking time, and it will support _fully_ dynamic scenes!
 
-While Bevy 0.17 adds the bevy_solari crate, it's intended as a long-term project. It is not yet usable by game developers. However, feel free to run the solari example (`cargo run --release --example solari --features bevy_solari` (realtime direct lighting, no denoising) or `cargo run --release --example solari --features bevy_solari -- --pathtracer` (non-realtime pathtracing)) to check out the progress we've made, and look forward to more work on Bevy Solari in future releases!
+While Bevy 0.17 adds the bevy_solari crate, it's intended as a long-term project. It is not yet usable by game developers. However, feel free to run the solari example (`cargo run --release --example solari --features bevy_solari` (realtime direct and 1-bounce indirect lighting, no denoising) or `cargo run --release --example solari --features bevy_solari -- --pathtracer` (non-realtime pathtracing)) to check out the progress we've made, and look forward to more work on Bevy Solari in future releases!
 
 (TODO: Embed bevy_solari logo here, or somewhere else that looks good)
 

release-content/release-notes/headless-widgets.md

@@ -1,7 +1,7 @@
 ---
 title: Headless Widgets
 authors: ["@viridia", "@ickshonpe", "@alice-i-cecile"]
-pull_requests: [19366, 19584, 19665, 19778, 19803, 20032, 20036]
+pull_requests: [19366, 19584, 19665, 19778, 19803, 20032, 20036, 20086]
 ---
 
 Bevy's `Button` and `Interaction` components have been around for a long time. Unfortunately