Guard against VisibilityClass being duplicated while cloning

[it-me-joda]

Objective

• This is the second attempt at "Fixes VisibilityClass gets duplicated when cloning an entity, causing issues with transparency #20884" after conversation in Guard against VisibilityClass duplicates #20891

Solution

• I followed the approach discussed in Guard against VisibilityClass duplicates #20891 to add #[component(clone_behavior=Ignore)] to avoid cloning this Component

Testing

• I tested the change with a simple repro. I'm not sure if I can unit test just the existence of this line but I'll see if I can and update accordingly.

use bevy::{prelude::*, render::view::NoIndirectDrawing};
fn main() {
    App::new()
        .insert_resource(ClearColor(Color::BLACK))
        .add_plugins(DefaultPlugins)
        .add_systems(Startup, startup)
        .run();
}
fn startup(
    mut cmd: Commands,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
    mut al: ResMut<AmbientLight>,
) {
    al.brightness = 5000.;
    cmd.spawn((
        Mesh3d(meshes.add(Cuboid::from_size(Vec3::new(4., 0.5, 0.1)))),
        MeshMaterial3d(materials.add(Color::srgb(1., 1., 0.))),
        Transform::from_xyz(0., 0., -2.),
    ));
    let mut id = cmd.spawn((
        Mesh3d(meshes.add(Cuboid::from_length(1.))),
        MeshMaterial3d(materials.add(Color::srgba(0., 0., 1., 0.5))),
        Transform::from_xyz(-0.5, 0., 0.),
    ));
    id.clone_and_spawn()
        .insert(Transform::from_xyz(0.5, 0., 0.));
    cmd.spawn((
        Camera3d::default(),
        Transform::from_xyz(0., 0., 10.).looking_at(Vec3::ZERO, Vec3::Y),
        NoIndirectDrawing,
    ));
}

Showcase

Before

After

[alice-i-cecile]

Can we leave a quick note in the doc comments about this behavior and why it exists? Other than that, I like this solution much better!

[dloukadakis]

Testing

• I tested the change with a simple repro. I'm not sure if I can unit test just the existence of this line but I'll see if I can and update accordingly.

The test I provided on the previous pull request is still relevant to test cloning does not introduce duplicates and cloning still adds a visibility class.

[it-me-joda]

Testing

• I tested the change with a simple repro. I'm not sure if I can unit test just the existence of this line but I'll see if I can and update accordingly.

The test I provided on the previous pull request is still relevant to test cloning does not introduce duplicates and cloning still adds a visibility class.

I'll see about adding it back in

[it-me-joda]

@dloukadakis I added your test back in and @alice-i-cecile I added some documentation. Let me know if there is anything else I can do to get this across the finish line. Thanks!

[alice-i-cecile]

@dloukadakis @tychedelia @eugineerd, want to give this a look? This needs two approvals to be merged.