Compatibility with Bloom

[stmdhms]

It seems like bevy_mod_outline is not compatible with bloom, even if the entities with outlines don't have any emissive color set.

Here's a sample scene without outlines enabled. The left cube has a red emissive color. The right cube has no emissive color, and has an OutlineBundle with outline.visible set to false. The rendered result is as expected:

If outline.visible on the right cube is set to true, the left cube suddenly loses its emissive glow:

I'm using bevy 0.13.1 and bevy_mod_outline 0.7.0.

Code to reproduce:

use bevy::{
    core_pipeline::bloom::*,
    prelude::*,
};
use bevy_mod_outline::*;

fn main() {
    App::new()
        .insert_resource(Msaa::Sample4)
        .insert_resource(ClearColor(Color::BLACK))
        .insert_resource(AmbientLight {
            color: Color::WHITE,
            brightness: 1000.0,
        })
        .add_plugins(DefaultPlugins)
        .add_plugins(OutlinePlugin)
        .add_systems(Startup, setup)
        .add_systems(Update, toggle_outline)
        .run();
}

fn setup(
    mut commands: Commands,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
) {
    commands.spawn((
        Camera3dBundle {
            camera: Camera {
                hdr: true,
                ..default()
            },
            transform: Transform::from_xyz(0.0, 5.0, 5.0).looking_at(Vec3::ZERO, Vec3::Y),
            ..default()
        },
        BloomSettings {
            intensity: 1.0,
            low_frequency_boost: 0.5,
            low_frequency_boost_curvature: 0.5,
            high_pass_frequency: 0.5,
            prefilter_settings: BloomPrefilterSettings {
                threshold: 3.0,
                threshold_softness: 0.6,
            },
            composite_mode: BloomCompositeMode::Additive,
        },
    ));


    let mut cube_mesh = Cuboid::new(1.0, 1.0, 1.0).mesh();
    cube_mesh.generate_outline_normals().unwrap();
    let cube = meshes.add(cube_mesh);
    commands
        .spawn(PbrBundle {
            mesh: cube.clone(),
            material: materials.add(StandardMaterial {
                base_color: Color::WHITE,
                emissive: Color::rgb_linear(2000.0, 0.0, 0.0),
                ..default()
            }),
            transform: Transform::from_xyz(-2.0, 0.0, 0.0),
            ..default()
        });

        commands
        .spawn(PbrBundle {
            mesh: cube.clone(),
            material: materials.add(StandardMaterial {
                base_color: Color::WHITE,
                ..default()
            }),
            transform: Transform::from_xyz(2.0, 0.0, 0.0),
            ..default()
        })
        .insert(OutlineBundle {
            outline: OutlineVolume {
                visible: false,
                colour: Color::rgba(0.0, 1.0, 0.0, 1.0),
                width: 5.0,
            },
            ..default()
        });
}


fn toggle_outline(
    time: Res<Time>,
    mut query: Query<&mut OutlineVolume>
) {
    for mut outline in query.iter_mut() {
        outline.visible = time.elapsed_seconds() % 2.0 < 1.0;
    }
}