How to render a PbrBundle through others?

[negasora]

How would I go about rendering a PbrBundle through other entities that are obscuring it?
In this example, I want the blue cube to render on top of the red cube and circular base.
My initial idea was to render it to a texture and show that in the ui, but I expect there's a much better solution.

Example Code (using version 0.12):

use bevy::prelude::*;

fn main() {
    App::new()
        .add_plugins(DefaultPlugins)
        .add_systems(Startup, setup)
        .run();
}

/// set up a simple 3D scene
fn setup(
    mut commands: Commands,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
) {
    // circular base
    commands.spawn(PbrBundle {
        mesh: meshes.add(shape::Circle::new(4.0).into()),
        material: materials.add(Color::WHITE.into()),
        transform: Transform::from_rotation(Quat::from_rotation_x(-std::f32::consts::FRAC_PI_2)),
        ..default()
    });
    // cube
    commands.spawn(PbrBundle {
        mesh: meshes.add(Mesh::from(shape::Cube { size: 1.0 })),
        material: materials.add(Color::rgb_u8(255, 0, 0).into()),
        transform: Transform::from_xyz(0.0, 0.5, 0.0),
        ..default()
    });

    // cube 2
    // How can this always be drawn on top?
    commands.spawn(PbrBundle {
        mesh: meshes.add(Mesh::from(shape::Cube { size: 1.0 })),
        material: materials.add(Color::rgb_u8(0, 0, 255).into()),
        transform: Transform::from_xyz(1.0, 0.0, -2.0),
        ..default()
    });
    // light
    commands.spawn(PointLightBundle {
        point_light: PointLight {
            intensity: 1500.0,
            shadows_enabled: true,
            ..default()
        },
        transform: Transform::from_xyz(4.0, 8.0, 4.0),
        ..default()
    });
    // camera
    commands.spawn(Camera3dBundle {
        transform: Transform::from_xyz(-2.5, 4.5, 9.0).looking_at(Vec3::ZERO, Vec3::Y),
        ..default()
    });
}

[negasora]

Of course I found the answer just after posting this 😅

Using two cameras with different RenderLayers and different ordering works for my use case.

use bevy::{prelude::*, core_pipeline::clear_color::ClearColorConfig, render::view::RenderLayers};

fn main() {
    App::new()
        .add_plugins(DefaultPlugins)
        .add_systems(Startup, setup)
        .run();
}

/// set up a simple 3D scene
fn setup(
    mut commands: Commands,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
) {
    // circular base
    commands.spawn(PbrBundle {
        mesh: meshes.add(shape::Circle::new(4.0).into()),
        material: materials.add(Color::WHITE.into()),
        transform: Transform::from_rotation(Quat::from_rotation_x(-std::f32::consts::FRAC_PI_2)),
        ..default()
    });

    // cube 1
    commands.spawn(PbrBundle {
        mesh: meshes.add(Mesh::from(shape::Cube { size: 1.0 })),
        material: materials.add(Color::rgb_u8(255, 0, 0).into()),
        transform: Transform::from_xyz(0.0, 0.5, 0.0),
        ..default()
    });

    // cube 2
    commands.spawn((
        PbrBundle {
        mesh: meshes.add(Mesh::from(shape::Cube { size: 1.0 })),
        material: materials.add(Color::rgb_u8(0, 0, 255).into()),
        transform: Transform::from_xyz(1.0, 0.0, -2.0),
        ..default()
    }, RenderLayers::layer(1)));

    // light
    commands.spawn((
        PointLightBundle {
        point_light: PointLight {
            intensity: 1500.0,
            shadows_enabled: true,
            ..default()
        },
        transform: Transform::from_xyz(4.0, 8.0, 4.0),
        ..default()
    }, RenderLayers::all()));

    // camera 1
    commands.spawn(Camera3dBundle {
        transform: Transform::from_xyz(-2.5, 4.5, 9.0).looking_at(Vec3::ZERO, Vec3::Y),
        ..default()
    });

    // camera 2
    commands.spawn((Camera3dBundle {
        transform: Transform::from_xyz(-2.5, 4.5, 9.0).looking_at(Vec3::ZERO, Vec3::Y),
        camera_3d: Camera3d {
            clear_color: ClearColorConfig::None,
            ..default()
        },
        camera: Camera {
            order: 1,
            ..default()
        },
        ..default()
    }, RenderLayers::layer(1)));

}