# Objective
- Fixes https://github.com/bevyengine/bevy/issues/11682
## Solution
- https://github.com/bevyengine/bevy/pull/4086 introduced an
optimization to not do redundant calculations, but did not take into
account changes to the resource `global_lights`. I believe that my patch
includes the optimization benefit but adds the required nuance to fix
said bug.
## Testing
The example originally given by
[@kirillsurkov](https://github.com/kirillsurkov) and then updated by me
to bevy 15.3 here:
https://github.com/bevyengine/bevy/issues/11682#issuecomment-2746287416
will not have shadows without this patch:
```rust
use bevy::prelude::*;
#[derive(Resource)]
struct State {
x: f32,
}
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_systems(Startup, setup)
.add_systems(Update, update)
.insert_resource(State { x: -40.0 })
.run();
}
fn setup(
mut commands: Commands,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<StandardMaterial>>,
) {
commands.spawn((
Mesh3d(meshes.add(Circle::new(4.0))),
MeshMaterial3d(materials.add(Color::WHITE)),
));
commands.spawn((
Mesh3d(meshes.add(Cuboid::new(1.0, 1.0, 1.0))),
MeshMaterial3d(materials.add(Color::linear_rgb(0.0, 1.0, 0.0))),
));
commands.spawn((
PointLight {
shadows_enabled: true,
..default()
},
Transform::from_xyz(4.0, 8.0, 4.0),
));
commands.spawn(Camera3d::default());
}
fn update(mut state: ResMut<State>, mut camera: Query<&mut Transform, With<Camera3d>>) {
let mut camera = camera.single_mut().unwrap();
let t = Vec3::new(state.x, 0.0, 10.0);
camera.translation = t;
camera.look_at(t - Vec3::Z, Vec3::Y);
state.x = 0.0;
}
```
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: JMS55 <47158642+JMS55@users.noreply.github.com>
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