Feathers slider - how does overrides work?

[Galedon1]

Hello,
I am trying to make a nice slider with feathers but I do not understand how the overrides component in the slider() function works.
Is there an example for it?
I tried this using AI:

fn setup(mut commands: Commands) {
    commands.spawn(Camera2d::default());

    // Create custom slider with circular thumb and grey colors
    commands.spawn(
        slider(
            SliderProps {
                value: 0.5,
                min: 0.0,
                max: 1.0,
            },
            // Override bundle for custom styling
            (
                // Make thumb circular by using maximum border radius
                Node {
                    border_radius: BorderRadius::MAX,
                    ..default()
                },
                // Custom grey gradient
                BackgroundGradient(vec![Gradient::Linear(LinearGradient {
                    angle: std::f32::consts::PI * 0.5,
                    stops: vec![
                        ColorStop::new(Color::srgb(0.5, 0.5, 0.5), Val::Percent(0.)),
                        ColorStop::new(Color::srgb(0.5, 0.5, 0.5), Val::Percent(50.)),
                        ColorStop::new(Color::srgb(0.3, 0.3, 0.3), Val::Percent(50.)),
                        ColorStop::new(Color::srgb(0.3, 0.3, 0.3), Val::Percent(100.)),
                    ],
                    color_space: InterpolationColorSpace::Srgba,
                })]),
            ),
        ),
    );
}

but both Node and BackgroundGradient raises an error of "duplicate component.

full error message:

thread 'main' (98352) panicked at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\bundle\info.rs:118:13:
Bundle (bevy_ui::ui_node::Node, bevy_ui_widgets::slider::Slider, bevy_feathers::controls::slider::SliderStyle, bevy_ui_widgets::slider::SliderValue, bevy_ui_widgets::slider::SliderRange, bevy_feathers::cursor::EntityCursor, bevy_input_focus::tab_navigation::TabIndex, bevy_ui::gradients::BackgroundGradient, (bevy_ui::ui_node::Node, bevy_ui::gradients::BackgroundGradient), bevy_ecs::spawn::SpawnRelatedBundle<bevy_ecs::hierarchy::ChildOf, bevy_ecs::spawn::Spawn<(bevy_ui::ui_node::Node, bevy_feathers::theme::ThemeFontColor, bevy_feathers::font_styles::InheritableFont, bevy_ecs::spawn::SpawnRelatedBundle<bevy_ecs::hierarchy::ChildOf, bevy_ecs::spawn::Spawn<(bevy_ui::widget::text::Text, bevy_feathers::theme::ThemedText, bevy_feathers::controls::slider::SliderValueText)>>)>>) has duplicate components: ["bevy_ui::ui_node::Node", "bevy_ui::gradients::BackgroundGradient"]
stack backtrace:
   0: std::panicking::panic_handler
             at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library\std\src\panicking.rs:698
   1: core::panicking::panic_fmt
             at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library\core\src\panicking.rs:80
   2: bevy_ecs::bundle::info::BundleInfo::new
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\bundle\info.rs:118
   3: bevy_ecs::bundle::info::impl$3::register_info::closure$0
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\bundle\info.rs:445
   4: enum2$<hashbrown::map::Entry<core::any::TypeId,bevy_ecs::bundle::info::BundleId,bevy_platform::hash::NoOpHash,hashbrown::raw::alloc::inner::Global> >::or_insert_with
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\hashbrown-0.16.1\src\map.rs:3636
   5: bevy_ecs::bundle::info::Bundles::register_info<tuple$<bevy_ui::ui_node::Node,bevy_ui_widgets::slider::Slider,bevy_feathers::controls::slider::SliderStyle,bevy_ui_widgets::slider::SliderValue,bevy_ui_widgets::slider::SliderRange,enum2$<bevy_feathers::cursor
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\bundle\info.rs:437
   6: bevy_ecs::world::World::register_bundle_info
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\world\mod.rs:3239
   7: bevy_ecs::bundle::spawner::BundleSpawner::new
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\bundle\spawner.rs:29
   8: bevy_ecs::world::World::spawn_at_unchecked
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\world\mod.rs:1083
   9: bevy_ecs::world::World::spawn_at_with_caller<tuple$<bevy_ui::ui_node::Node,bevy_ui_widgets::slider::Slider,bevy_feathers::controls::slider::SliderStyle,bevy_ui_widgets::slider::SliderValue,bevy_ui_widgets::slider::SliderRange,enum2$<bevy_feathers::cursor::
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\world\mod.rs:1068
  10: bevy_ecs::system::commands::impl$2::spawn::closure$0
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\system\commands\mod.rs:406
  11: bevy_ecs::system::commands::command::impl$0::apply
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\system\commands\command.rs:62
  12: bevy_ecs::error::command_handling::impl$0::handle_error::closure$0
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\error\command_handling.rs:45
  13: bevy_ecs::system::commands::command::impl$0::apply
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\system\commands\command.rs:62
  14: bevy_ecs::world::command_queue::impl$5::push::closure$0
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\world\command_queue.rs:185
  15: core::ops::function::FnOnce::call_once<bevy_ecs::world::command_queue::impl$5::push::closure_env$0<bevy_ecs::error::command_handling::impl$0::handle_error::closure_env$0<bevy_ecs::system::commands::impl$2::spawn::closure_env$0<tuple$<bevy_ui::ui_node::Node
             at C:\Users\User\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\src\rust\library\core\src\ops\function.rs:250
  16: bevy_ecs::world::command_queue::impl$5::apply_or_drop_queued::closure$0
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\world\command_queue.rs:275
  17: core::panic::unwind_safe::impl$25::call_once
             at C:\Users\User\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\src\rust\library\core\src\panic\unwind_safe.rs:274
  18: std::panicking::catch_unwind::do_call
             at C:\Users\User\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\src\rust\library\std\src\panicking.rs:590
  19: std::panicking::catch_unwind
             at C:\Users\User\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\src\rust\library\std\src\panicking.rs:553
  20: std::panic::catch_unwind
             at C:\Users\User\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\src\rust\library\std\src\panic.rs:359
  21: bevy_ecs::world::command_queue::RawCommandQueue::apply_or_drop_queued
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\world\command_queue.rs:280
  22: bevy_ecs::world::command_queue::CommandQueue::apply
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\world\command_queue.rs:106
  23: bevy_ecs::world::command_queue::impl$7::apply
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\world\command_queue.rs:342
  24: bevy_ecs::system::system_param::impl$22::apply
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\system\system_param.rs:1349
  25: bevy_ecs::system::system_param::impl$107::apply
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\system\system_param.rs:2242
  26: bevy_ecs::system::commands::_::impl$0::apply
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\system\commands\mod.rs:161
  27: bevy_ecs::schedule::executor::multi_threaded::apply_deferred::closure$0
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\schedule\executor\multi_threaded.rs:809
  28: core::ops::function::FnOnce::call_once
             at C:\Users\User\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\src\rust\library\core\src\ops\function.rs:250
  29: core::panic::unwind_safe::impl$25::call_once
             at C:\Users\User\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\src\rust\library\core\src\panic\unwind_safe.rs:274
  30: std::panicking::catch_unwind::do_call
             at C:\Users\User\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\src\rust\library\std\src\panicking.rs:590
  31: std::panicking::catch_unwind
             at C:\Users\User\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\src\rust\library\std\src\panicking.rs:553
  32: std::panic::catch_unwind
             at C:\Users\User\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\src\rust\library\std\src\panic.rs:359
  33: bevy_ecs::schedule::executor::multi_threaded::apply_deferred
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\schedule\executor\multi_threaded.rs:808
  34: bevy_ecs::schedule::executor::multi_threaded::impl$2::run
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\schedule\executor\multi_threaded.rs:302
  35: bevy_ecs::schedule::schedule::Schedule::run
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\schedule\schedule.rs:547
  36: bevy_ecs::world::impl$4::try_run_schedule::closure$0
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\world\mod.rs:3732
  37: bevy_ecs::world::World::try_schedule_scope<tuple$<>,bevy_ecs::intern::Interned<dyn$<bevy_ecs::schedule::set::ScheduleLabel> >,bevy_ecs::world::impl$4::try_run_schedule::closure_env$0<bevy_ecs::intern::Interned<dyn$<bevy_ecs::schedule::set::ScheduleLabel> >
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\world\mod.rs:3665
  38: bevy_ecs::world::World::try_resource_scope
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\world\mod.rs:2826
  39: bevy_ecs::world::World::resource_scope<bevy_app::main_schedule::MainScheduleOrder,tuple$<>,bevy_app::main_schedule::impl$2::run_main::closure_env$0>
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\world\mod.rs:2705
  40: bevy_app::main_schedule::Main::run_main
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_app-0.18.0\src\main_schedule.rs:283
  41: core::ops::function::FnMut::call_mut
             at C:\Users\User\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\src\rust\library\core\src\ops\function.rs:166
  42: core::ops::function::impls::impl$3::call_mut
             at C:\Users\User\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\src\rust\library\core\src\ops\function.rs:298
  43: bevy_ecs::system::exclusive_function_system::impl$5::run::call_inner
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\system\exclusive_function_system.rs:270
  44: bevy_ecs::system::exclusive_function_system::impl$5::run
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\system\exclusive_function_system.rs:273
  45: bevy_ecs::system::exclusive_function_system::impl$2::run_unsafe::closure$0
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\system\exclusive_function_system.rs:135
  46: bevy_ecs::world::World::last_change_tick_scope
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\world\mod.rs:3144
  47: bevy_ecs::system::exclusive_function_system::impl$2::run_unsafe
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\system\exclusive_function_system.rs:113
  48: bevy_ecs::system::system::System::run_without_applying_deferred<bevy_ecs::system::exclusive_function_system::ExclusiveFunctionSystem<void (*)(bevy_ecs::system::system_param::Local<bool>),tuple$<>,void (*)(ref_mut$<bevy_ecs::world::World>,bevy_ecs::system::
             at C:\Users\User\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\bevy_ecs-0.18.0\src\system\system.rs:138
  49: core::hint::black_box
             at C:\Users\User\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib\rustlib\src\rust\library\core\src\hint.rs:472
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
Encountered a panic when applying buffers for system `BevyPlayground::setup`!
2026-01-15T10:31:21.538186Z  WARN bevy_ecs::world::command_queue: CommandQueue has un-applied commands being dropped. Did you forget to call SystemState::apply?
Encountered a panic in system `bevy_app::main_schedule::Main::run_main`!
error: process didn't exit successfully: `target\debug\BevyPlayground.exe` (exit code: 101)

Process finished with exit code 101

[mnmaita]

I feel like you have to use insert() to override already existing components in this specific scenario... Not ideal but it's a way you can circumvent this. I feel like the overrides parameter is not quite that but just an additional bundle that you can add to the entity.

Maybe @viridia and @ickshonpe can shed some light here as I'm not 100% sure if there's some workaround to this.

[viridia]

The 'overrides' parameter should be renamed, it doesn't actually override - it can only add new components. This is a limitation of how bundles work. I don't think I really understood this when I first wrote this code.

This will get solved much more neatly when we implement the BSN version of these widgets, as BSN is very flexible about overriding and patching.

[mnmaita]

Thanks for clarifying this!

[viridia]

You might be better off starting with a headless widget rather than feathers. Have a look at the color_slider widget:

bevy/crates/bevy_feathers/src/controls/color_slider.rs

Line 187 in 2d4bf0c

pub fn color_slider<B: Bundle>(props: ColorSliderProps, overrides: B) -> impl Bundle {

[Galedon1]

Thank you for the recommendation - this is actually my current solution. the problem is that as far I understood the color_slider is meant to be used for color-mixing, having a bound component ColorChannel. Do you have any tips how to make a color_slider with a single-color background?

[viridia]

Just cut & paste the color slider code and replace the gradient with a solid background color.