From 1f1511c7753b1a7da3ec45c192c8ec3ef71a7788 Mon Sep 17 00:00:00 2001
From: atlas dostal <rodol@rivalrebels.com>
Date: Thu, 25 Jan 2024 01:13:37 -0800
Subject: [PATCH 1/4] Add Animated Material example

---
 Cargo.toml                       | 11 +++++
 examples/3d/animated_material.rs | 79 ++++++++++++++++++++++++++++++++
 examples/README.md               |  1 +
 3 files changed, 91 insertions(+)
 create mode 100644 examples/3d/animated_material.rs

diff --git a/Cargo.toml b/Cargo.toml
index 65bf72603684f..b04b8f7cdd072 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -552,6 +552,17 @@ description = "Demonstrates how to use the `Camera::viewport_to_world` method"
 category = "3D Rendering"
 wasm = true
 
+[[example]]
+name = "animated_material"
+path = "examples/3d/animated_material.rs"
+doc-scrape-examples = true
+
+[package.metadata.example.animated_material]
+name = "Animated Material"
+description = "Shows how to animate material properties"
+category = "3D Rendering"
+wasm = true
+
 [[example]]
 name = "generate_custom_mesh"
 path = "examples/3d/generate_custom_mesh.rs"
diff --git a/examples/3d/animated_material.rs b/examples/3d/animated_material.rs
new file mode 100644
index 0000000000000..f54381e21b39c
--- /dev/null
+++ b/examples/3d/animated_material.rs
@@ -0,0 +1,79 @@
+//! Shows how to animate material properties
+
+use bevy::prelude::*;
+use bevy_internal::utils::HashSet;
+use core::f32::consts::PI;
+
+fn main() {
+    App::new()
+        .add_plugins(DefaultPlugins)
+        .add_systems(Startup, setup)
+        .add_systems(Update, (animate_materials, make_materials_unique))
+        .run();
+}
+
+fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
+    commands.spawn((
+        Camera3dBundle {
+            transform: Transform::from_xyz(3.0, 1.0, 3.0)
+                .looking_at(Vec3::new(0.0, 0.2, 0.0), Vec3::Y),
+            ..default()
+        },
+        EnvironmentMapLight {
+            diffuse_map: asset_server.load("environment_maps/pisa_diffuse_rgb9e5_zstd.ktx2"),
+            specular_map: asset_server.load("environment_maps/pisa_specular_rgb9e5_zstd.ktx2"),
+            intensity: 1500.0,
+        },
+    ));
+
+    let helmet = asset_server.load("models/FlightHelmet/FlightHelmet.gltf#Scene0");
+    for x in -2..3 {
+        for z in -2..3 {
+            commands.spawn(SceneBundle {
+                scene: helmet.clone(),
+                transform: Transform::from_translation(Vec3::new(x as f32, 0.0, z as f32)),
+                ..default()
+            });
+        }
+    }
+}
+
+fn animate_materials(
+    material_handles: Query<&Handle<StandardMaterial>>,
+    time: Res<Time>,
+    mut materials: ResMut<Assets<StandardMaterial>>,
+) {
+    for (i, material_handle) in material_handles.iter().enumerate() {
+        if let Some(material) = materials.get_mut(material_handle) {
+            let color = Color::hsl(
+                ((i as f32 * 2.345 + time.elapsed_seconds_wrapped()) * 100.0) % 360.0,
+                1.0,
+                0.5,
+            );
+            material.base_color = color;
+            material.emissive = color;
+        }
+    }
+}
+
+/// This is needed because by default assets are loaded with shared materials
+/// But we want to animate every helmet independently of the others, so we must duplicate the materials
+fn make_materials_unique(
+    mut material_handles: Query<&mut Handle<StandardMaterial>>,
+    mut materials: ResMut<Assets<StandardMaterial>>,
+    mut ran: Local<bool>,
+) {
+    if *ran {
+        return;
+    }
+    let mut set = HashSet::new();
+    for mut material_handle in material_handles.iter_mut() {
+        if set.contains(&material_handle.id()) {
+            let material = materials.get(&*material_handle).unwrap().clone();
+            *material_handle = materials.add(material);
+        } else {
+            set.insert(material_handle.id());
+        }
+        *ran = true;
+    }
+}
diff --git a/examples/README.md b/examples/README.md
index e03d0a0db27d2..495ee692c0061 100644
--- a/examples/README.md
+++ b/examples/README.md
@@ -121,6 +121,7 @@ Example | Description
 [3D Scene](../examples/3d/3d_scene.rs) | Simple 3D scene with basic shapes and lighting
 [3D Shapes](../examples/3d/3d_shapes.rs) | A scene showcasing the built-in 3D shapes
 [3D Viewport To World](../examples/3d/3d_viewport_to_world.rs) | Demonstrates how to use the `Camera::viewport_to_world` method
+[Animated Material](../examples/3d/animated_material.rs) | Shows how to animate material properties
 [Anti-aliasing](../examples/3d/anti_aliasing.rs) | Compares different anti-aliasing methods
 [Atmospheric Fog](../examples/3d/atmospheric_fog.rs) | A scene showcasing the atmospheric fog effect
 [Blend Modes](../examples/3d/blend_modes.rs) | Showcases different blend modes

From bb4982ea6fed9b68d8cbc23ad7525ce1732b322c Mon Sep 17 00:00:00 2001
From: atlas dostal <rodol@rivalrebels.com>
Date: Thu, 25 Jan 2024 01:15:49 -0800
Subject: [PATCH 2/4] Tweak camera

---
 examples/3d/animated_material.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/3d/animated_material.rs b/examples/3d/animated_material.rs
index f54381e21b39c..3c73b1e308970 100644
--- a/examples/3d/animated_material.rs
+++ b/examples/3d/animated_material.rs
@@ -16,7 +16,7 @@ fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
     commands.spawn((
         Camera3dBundle {
             transform: Transform::from_xyz(3.0, 1.0, 3.0)
-                .looking_at(Vec3::new(0.0, 0.2, 0.0), Vec3::Y),
+                .looking_at(Vec3::new(0.0, -0.5, 0.0), Vec3::Y),
             ..default()
         },
         EnvironmentMapLight {

From 751a7ecf80372be9ee2d8368a2e9324d9ff5cedc Mon Sep 17 00:00:00 2001
From: atlas dostal <rodol@rivalrebels.com>
Date: Thu, 25 Jan 2024 21:07:36 -0800
Subject: [PATCH 3/4] Remove unused import

---
 examples/3d/animated_material.rs | 1 -
 1 file changed, 1 deletion(-)

diff --git a/examples/3d/animated_material.rs b/examples/3d/animated_material.rs
index 3c73b1e308970..847747dc0369b 100644
--- a/examples/3d/animated_material.rs
+++ b/examples/3d/animated_material.rs
@@ -2,7 +2,6 @@
 
 use bevy::prelude::*;
 use bevy_internal::utils::HashSet;
-use core::f32::consts::PI;
 
 fn main() {
     App::new()

From 87692f2396c95753e93993ba4bc73bc2785f0298 Mon Sep 17 00:00:00 2001
From: atlas dostal <rodol@rivalrebels.com>
Date: Thu, 25 Jan 2024 21:11:14 -0800
Subject: [PATCH 4/4] Fix import

---
 examples/3d/animated_material.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/3d/animated_material.rs b/examples/3d/animated_material.rs
index 847747dc0369b..4803fc64272e0 100644
--- a/examples/3d/animated_material.rs
+++ b/examples/3d/animated_material.rs
@@ -1,7 +1,7 @@
 //! Shows how to animate material properties
 
 use bevy::prelude::*;
-use bevy_internal::utils::HashSet;
+use bevy::utils::HashSet;
 
 fn main() {
     App::new()