forestia/bevy
2
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Add a viewport UI widget (#17253)

Browse Source 
# Objective

Add a viewport widget.

## Solution

- Add a new `ViewportNode` component to turn a UI node into a viewport.
- Add `viewport_picking` to pass pointer inputs from other pointers to
the viewport's pointer.
- Notably, this is somewhat functionally different from the viewport
widget in [the editor
prototype](https://github.com/bevyengine/bevy_editor_prototypes/pull/110/files#L124),
which just moves the pointer's location onto the render target. Viewport
widgets have their own pointers.
  - Care is taken to handle dragging in and out of viewports.
- Add `update_viewport_render_target_size` to update the viewport node's
render target's size if the node size changes.
- Feature gate picking-related viewport items behind
`bevy_ui_picking_backend`.

## Testing

I've been using an example I made to test the widget (and added it as
`viewport_node`):

<details><summary>Code</summary>

```rust
//! A simple scene to demonstrate spawning a viewport widget. The example will demonstrate how to
//! pick entities visible in the widget's view.

use bevy::picking::pointer::PointerInteraction;
use bevy::prelude::*;

use bevy::ui::widget::ViewportNode;
use bevy::{
    image::{TextureFormatPixelInfo, Volume},
    window::PrimaryWindow,
};
use bevy_render::{
    camera::RenderTarget,
    render_resource::{
        Extent3d, TextureDescriptor, TextureDimension, TextureFormat, TextureUsages,
    },
};

fn main() {
    App::new()
        .add_plugins((DefaultPlugins, MeshPickingPlugin))
        .add_systems(Startup, test)
        .add_systems(Update, draw_mesh_intersections)
        .run();
}

#[derive(Component, Reflect, Debug)]
#[reflect(Component)]
struct Shape;

fn test(
    mut commands: Commands,
    window: Query<&Window, With<PrimaryWindow>>,
    mut images: ResMut<Assets<Image>>,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
) {
    // Spawn a UI camera
    commands.spawn(Camera3d::default());

    // Set up an texture for the 3D camera to render to
    let window = window.get_single().unwrap();
    let window_size = window.physical_size();
    let size = Extent3d {
        width: window_size.x,
        height: window_size.y,
        ..default()
    };
    let format = TextureFormat::Bgra8UnormSrgb;
    let image = Image {
        data: Some(vec![0; size.volume() * format.pixel_size()]),
        texture_descriptor: TextureDescriptor {
            label: None,
            size,
            dimension: TextureDimension::D2,
            format,
            mip_level_count: 1,
            sample_count: 1,
            usage: TextureUsages::TEXTURE_BINDING
                | TextureUsages::COPY_DST
                | TextureUsages::RENDER_ATTACHMENT,
            view_formats: &[],
        },
        ..default()
    };
    let image_handle = images.add(image);

    // Spawn the 3D camera
    let camera = commands
        .spawn((
            Camera3d::default(),
            Camera {
                // Render this camera before our UI camera
                order: -1,
                target: RenderTarget::Image(image_handle.clone().into()),
                ..default()
            },
        ))
        .id();

    // Spawn something for the 3D camera to look at
    commands
        .spawn((
            Mesh3d(meshes.add(Cuboid::new(5.0, 5.0, 5.0))),
            MeshMaterial3d(materials.add(Color::WHITE)),
            Transform::from_xyz(0.0, 0.0, -10.0),
            Shape,
        ))
        // We can observe pointer events on our objects as normal, the
        // `bevy::ui::widgets::viewport_picking` system will take care of ensuring our viewport
        // clicks pass through
        .observe(on_drag_cuboid);

    // Spawn our viewport widget
    commands
        .spawn((
            Node {
                position_type: PositionType::Absolute,
                top: Val::Px(50.0),
                left: Val::Px(50.0),
                width: Val::Px(200.0),
                height: Val::Px(200.0),
                border: UiRect::all(Val::Px(5.0)),
                ..default()
            },
            BorderColor(Color::WHITE),
            ViewportNode::new(camera),
        ))
        .observe(on_drag_viewport);
}

fn on_drag_viewport(drag: Trigger<Pointer<Drag>>, mut node_query: Query<&mut Node>) {
    if matches!(drag.button, PointerButton::Secondary) {
        let mut node = node_query.get_mut(drag.target()).unwrap();

        if let (Val::Px(top), Val::Px(left)) = (node.top, node.left) {
            node.left = Val::Px(left + drag.delta.x);
            node.top = Val::Px(top + drag.delta.y);
        };
    }
}

fn on_drag_cuboid(drag: Trigger<Pointer<Drag>>, mut transform_query: Query<&mut Transform>) {
    if matches!(drag.button, PointerButton::Primary) {
        let mut transform = transform_query.get_mut(drag.target()).unwrap();
        transform.rotate_y(drag.delta.x * 0.02);
        transform.rotate_x(drag.delta.y * 0.02);
    }
}

fn draw_mesh_intersections(
    pointers: Query<&PointerInteraction>,
    untargetable: Query<Entity, Without<Shape>>,
    mut gizmos: Gizmos,
) {
    for (point, normal) in pointers
        .iter()
        .flat_map(|interaction| interaction.iter())
        .filter_map(|(entity, hit)| {
            if !untargetable.contains(*entity) {
                hit.position.zip(hit.normal)
            } else {
                None
            }
        })
    {
        gizmos.arrow(point, point + normal.normalize() * 0.5, Color::WHITE);
    }
}
```

</details>

## Showcase


https://github.com/user-attachments/assets/39f44eac-2c2a-4fd9-a606-04171f806dc1

## Open Questions

- <del>Not sure whether the entire widget should be feature gated behind
`bevy_ui_picking_backend` or not? I chose a partial approach since maybe
someone will want to use the widget without any picking being
involved.</del>
- <del>Is `PickSet::Last` the expected set for `viewport_picking`?
Perhaps `PickSet::Input` is more suited.</del>
- <del>Can `dragged_last_frame` be removed in favor of a better dragging
check? Another option that comes to mind is reading `Drag` and `DragEnd`
events, but this seems messier.</del>

---------

Co-authored-by: ickshonpe <david.curthoys@googlemail.com>
Co-authored-by: François Mockers <mockersf@gmail.com>
This commit is contained in:
Antony 2025-05-05 18:57:37 -04:00 committed by GitHub
parent 55bb59b844
commit bf42cb3532
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
9 changed files with 445 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
Cargo.toml
View File

@ -3510,6 +3510,17 @@ description = "An example for debugging viewport coordinates"
category = "UI (User Interface)"
wasm = true
[[example]]
name = "viewport_node"
path = "examples/ui/viewport_node.rs"
doc-scrape-examples = true
[package.metadata.example.viewport_node]
name = "Viewport Node"
description = "Demonstrates how to create a viewport node with picking support"
category = "UI (User Interface)"
wasm = true
# Window
[[example]]
name = "clear_color"

3
crates/bevy_ui/Cargo.toml
View File

@ -35,6 +35,7 @@ bevy_platform = { path = "../bevy_platform", version = "0.16.0-dev", default-fea
# other
taffy = { version = "0.7" }
serde = { version = "1", features = ["derive"], optional = true }
uuid = { version = "1.1", features = ["v4"], optional = true }
bytemuck = { version = "1.5", features = ["derive"] }
thiserror = { version = "2", default-features = false }
derive_more = { version = "1", default-features = false, features = ["from"] }
@ -51,7 +52,7 @@ serialize = [
"bevy_math/serialize",
"bevy_platform/serialize",
]
bevy_ui_picking_backend = ["bevy_picking"]
bevy_ui_picking_backend = ["bevy_picking", "dep:uuid"]
bevy_ui_debug = []
# Experimental features

21
crates/bevy_ui/src/lib.rs
View File

@ -19,6 +19,8 @@ pub mod widget;
pub mod picking_backend;
use bevy_derive::{Deref, DerefMut};
#[cfg(feature = "bevy_ui_picking_backend")]
use bevy_picking::PickSet;
use bevy_reflect::{std_traits::ReflectDefault, Reflect};
mod accessibility;
// This module is not re-exported, but is instead made public.
@ -39,7 +41,7 @@ pub use render::*;
pub use ui_material::*;
pub use ui_node::*;
use widget::{ImageNode, ImageNodeSize};
use widget::{ImageNode, ImageNodeSize, ViewportNode};
/// The UI prelude.
///
@ -59,7 +61,7 @@ pub mod prelude {
geometry::*,
ui_material::*,
ui_node::*,
widget::{Button, ImageNode, Label, NodeImageMode},
widget::{Button, ImageNode, Label, NodeImageMode, ViewportNode},
Interaction, MaterialNode, UiMaterialPlugin, UiScale,
},
// `bevy_sprite` re-exports for texture slicing
@ -157,6 +159,7 @@ impl Plugin for UiPlugin {
.register_type::<UiTargetCamera>()
.register_type::<ImageNode>()
.register_type::<ImageNodeSize>()
.register_type::<ViewportNode>()
.register_type::<UiRect>()
.register_type::<UiScale>()
.register_type::<BorderColor>()
@ -187,7 +190,8 @@ impl Plugin for UiPlugin {
);
#[cfg(feature = "bevy_ui_picking_backend")]
app.add_plugins(picking_backend::UiPickingPlugin);
app.add_plugins(picking_backend::UiPickingPlugin)
.add_systems(First, widget::viewport_picking.in_set(PickSet::PostInput));
let ui_layout_system_config = ui_layout_system
.in_set(UiSystem::Layout)
@ -205,9 +209,10 @@ impl Plugin for UiPlugin {
ui_layout_system_config,
ui_stack_system
.in_set(UiSystem::Stack)
// the systems don't care about stack index
// These systems don't care about stack index
.ambiguous_with(update_clipping_system)
.ambiguous_with(ui_layout_system)
.ambiguous_with(widget::update_viewport_render_target_size)
.in_set(AmbiguousWithTextSystem),
update_clipping_system.after(TransformSystem::TransformPropagate),
// Potential conflicts: `Assets<Image>`
@ -218,8 +223,16 @@ impl Plugin for UiPlugin {
.in_set(UiSystem::Content)
.in_set(AmbiguousWithTextSystem)
.in_set(AmbiguousWithUpdateText2DLayout),
// Potential conflicts: `Assets<Image>`
// `widget::text_system` and `bevy_text::update_text2d_layout` run independently
// since this system will only ever update viewport images.
widget::update_viewport_render_target_size
.in_set(UiSystem::PostLayout)
.in_set(AmbiguousWithTextSystem)
.in_set(AmbiguousWithUpdateText2DLayout),
),
);
build_text_interop(app);
if !self.enable_rendering {

67
crates/bevy_ui/src/render/mod.rs
View File

@ -7,7 +7,7 @@ pub mod ui_texture_slice_pipeline;
#[cfg(feature = "bevy_ui_debug")]
mod debug_overlay;
use crate::widget::ImageNode;
use crate::widget::{ImageNode, ViewportNode};
use crate::{
BackgroundColor, BorderColor, BoxShadowSamples, CalculatedClip, ComputedNode,
ComputedNodeTarget, Outline, ResolvedBorderRadius, TextShadow, UiAntiAlias,
@ -107,6 +107,7 @@ pub enum RenderUiSystem {
ExtractImages,
ExtractTextureSlice,
ExtractBorders,
ExtractViewportNodes,
ExtractTextBackgrounds,
ExtractTextShadows,
ExtractText,
@ -152,6 +153,7 @@ pub fn build_ui_render(app: &mut App) {
extract_uinode_background_colors.in_set(RenderUiSystem::ExtractBackgrounds),
extract_uinode_images.in_set(RenderUiSystem::ExtractImages),
extract_uinode_borders.in_set(RenderUiSystem::ExtractBorders),
extract_viewport_nodes.in_set(RenderUiSystem::ExtractViewportNodes),
extract_text_background_colors.in_set(RenderUiSystem::ExtractTextBackgrounds),
extract_text_shadows.in_set(RenderUiSystem::ExtractTextShadows),
extract_text_sections.in_set(RenderUiSystem::ExtractText),
@ -697,6 +699,69 @@ pub fn extract_ui_camera_view(
transparent_render_phases.retain(|entity, _| live_entities.contains(entity));
}
pub fn extract_viewport_nodes(
mut commands: Commands,
mut extracted_uinodes: ResMut<ExtractedUiNodes>,
camera_query: Extract<Query<&Camera>>,
uinode_query: Extract<
Query<(
Entity,
&ComputedNode,
&GlobalTransform,
&InheritedVisibility,
Option<&CalculatedClip>,
&ComputedNodeTarget,
&ViewportNode,
)>,
>,
camera_map: Extract<UiCameraMap>,
) {
let mut camera_mapper = camera_map.get_mapper();
for (entity, uinode, transform, inherited_visibility, clip, camera, viewport_node) in
&uinode_query
{
// Skip invisible images
if !inherited_visibility.get() || uinode.is_empty() {
continue;
}
let Some(extracted_camera_entity) = camera_mapper.map(camera) else {
continue;
};
let Some(image) = camera_query
.get(viewport_node.camera)
.ok()
.and_then(|camera| camera.target.as_image())
else {
continue;
};
extracted_uinodes.uinodes.push(ExtractedUiNode {
render_entity: commands.spawn(TemporaryRenderEntity).id(),
stack_index: uinode.stack_index,
color: LinearRgba::WHITE,
rect: Rect {
min: Vec2::ZERO,
max: uinode.size,
},
clip: clip.map(|clip| clip.clip),
image: image.id(),
extracted_camera_entity,
item: ExtractedUiItem::Node {
atlas_scaling: None,
transform: transform.compute_matrix(),
flip_x: false,
flip_y: false,
border: uinode.border(),
border_radius: uinode.border_radius(),
node_type: NodeType::Rect,
},
main_entity: entity.into(),
});
}
}
pub fn extract_text_sections(
mut commands: Commands,
mut extracted_uinodes: ResMut<ExtractedUiNodes>,

4
crates/bevy_ui/src/widget/mod.rs
View File

@ -3,11 +3,11 @@
mod button;
mod image;
mod label;
mod text;
mod viewport;
pub use button::*;
pub use image::*;
pub use label::*;
pub use text::*;
pub use viewport::*;

176
crates/bevy_ui/src/widget/viewport.rs Normal file
View File

@ -0,0 +1,176 @@
use bevy_asset::Assets;
use bevy_ecs::{
component::Component,
entity::Entity,
event::EventReader,
query::{Changed, Or},
reflect::ReflectComponent,
system::{Commands, Query, Res, ResMut},
};
use bevy_image::Image;
use bevy_math::Rect;
#[cfg(feature = "bevy_ui_picking_backend")]
use bevy_picking::{
events::PointerState,
hover::HoverMap,
pointer::{Location, PointerId, PointerInput, PointerLocation},
};
use bevy_platform::collections::HashMap;
use bevy_reflect::Reflect;
use bevy_render::{
camera::{Camera, NormalizedRenderTarget},
render_resource::Extent3d,
};
use bevy_transform::components::GlobalTransform;
use bevy_utils::default;
#[cfg(feature = "bevy_ui_picking_backend")]
use uuid::Uuid;
use crate::{ComputedNode, Node};
/// Component used to render a [`Camera::target`] to a node.
///
/// # See Also
///
/// [`update_viewport_render_target_size`]
#[derive(Component, Debug, Clone, Copy, Reflect)]
#[reflect(Component, Debug)]
#[require(Node)]
#[cfg_attr(
feature = "bevy_ui_picking_backend",
require(PointerId::Custom(Uuid::new_v4()))
)]
pub struct ViewportNode {
/// The entity representing the [`Camera`] associated with this viewport.
///
/// Note that removing the [`ViewportNode`] component will not despawn this entity.
pub camera: Entity,
}
impl ViewportNode {
/// Creates a new [`ViewportNode`] with a given `camera`.
pub fn new(camera: Entity) -> Self {
Self { camera }
}
}
#[cfg(feature = "bevy_ui_picking_backend")]
/// Handles viewport picking logic.
///
/// Viewport entities that are being hovered or dragged will have all pointer inputs sent to them.
pub fn viewport_picking(
mut commands: Commands,
mut viewport_query: Query<(
Entity,
&ViewportNode,
&PointerId,
&mut PointerLocation,
&ComputedNode,
&GlobalTransform,
)>,
camera_query: Query<&Camera>,
hover_map: Res<HoverMap>,
pointer_state: Res<PointerState>,
mut pointer_inputs: EventReader<PointerInput>,
) {
// Handle hovered entities.
let mut viewport_picks: HashMap<Entity, PointerId> = hover_map
.iter()
.flat_map(|(hover_pointer_id, hits)| {
hits.iter()
.filter(|(entity, _)| viewport_query.contains(**entity))
.map(|(entity, _)| (*entity, *hover_pointer_id))
})
.collect();
// Handle dragged entities, which need to be considered for dragging in and out of viewports.
for ((pointer_id, _), pointer_state) in pointer_state.pointer_buttons.iter() {
for &target in pointer_state
.dragging
.keys()
.filter(|&entity| viewport_query.contains(*entity))
{
viewport_picks.insert(target, *pointer_id);
}
}
for (
viewport_entity,
&viewport,
&viewport_pointer_id,
mut viewport_pointer_location,
computed_node,
global_transform,
) in &mut viewport_query
{
let Some(pick_pointer_id) = viewport_picks.get(&viewport_entity) else {
// Lift the viewport pointer if it's not being used.
viewport_pointer_location.location = None;
continue;
};
let Ok(camera) = camera_query.get(viewport.camera) else {
continue;
};
let Some(cam_viewport_size) = camera.logical_viewport_size() else {
continue;
};
// Create a `Rect` in *physical* coordinates centered at the node's GlobalTransform
let node_rect = Rect::from_center_size(
global_transform.translation().truncate(),
computed_node.size(),
);
// Location::position uses *logical* coordinates
let top_left = node_rect.min * computed_node.inverse_scale_factor();
let logical_size = computed_node.size() * computed_node.inverse_scale_factor();
let Some(target) = camera.target.as_image() else {
continue;
};
for input in pointer_inputs
.read()
.filter(|input| &input.pointer_id == pick_pointer_id)
{
let local_position = (input.location.position - top_left) / logical_size;
let position = local_position * cam_viewport_size;
let location = Location {
position,
target: NormalizedRenderTarget::Image(target.clone().into()),
};
viewport_pointer_location.location = Some(location.clone());
commands.send_event(PointerInput {
location,
pointer_id: viewport_pointer_id,
action: input.action,
});
}
}
}
/// Updates the size of the associated render target for viewports when the node size changes.
pub fn update_viewport_render_target_size(
viewport_query: Query<
(&ViewportNode, &ComputedNode),
Or<(Changed<ComputedNode>, Changed<ViewportNode>)>,
>,
camera_query: Query<&Camera>,
mut images: ResMut<Assets<Image>>,
) {
for (viewport, computed_node) in &viewport_query {
let camera = camera_query.get(viewport.camera).unwrap();
let size = computed_node.size();
let Some(image_handle) = camera.target.as_image() else {
continue;
};
let size = Extent3d {
width: u32::max(1, size.x as u32),
height: u32::max(1, size.y as u32),
..default()
};
images.get_mut(image_handle).unwrap().resize(size);
}
}

1
examples/README.md
View File

@ -567,6 +567,7 @@ Example | Description
[UI Texture Slice Flipping and Tiling](../examples/ui/ui_texture_slice_flip_and_tile.rs) | Illustrates how to flip and tile images with 9 Slicing in UI
[UI Z-Index](../examples/ui/z_index.rs) | Demonstrates how to control the relative depth (z-position) of UI elements
[Viewport Debug](../examples/ui/viewport_debug.rs) | An example for debugging viewport coordinates
[Viewport Node](../examples/ui/viewport_node.rs) | Demonstrates how to create a viewport node with picking support
[Window Fallthrough](../examples/ui/window_fallthrough.rs) | Illustrates how to access `winit::window::Window`'s `hittest` functionality.
## Window

148
examples/ui/viewport_node.rs Normal file
View File

@ -0,0 +1,148 @@
//! A simple scene to demonstrate spawning a viewport widget. The example will demonstrate how to
//! pick entities visible in the widget's view.
use bevy::{
image::{TextureFormatPixelInfo, Volume},
picking::pointer::PointerInteraction,
prelude::*,
render::{
camera::RenderTarget,
render_resource::{
Extent3d, TextureDescriptor, TextureDimension, TextureFormat, TextureUsages,
},
},
ui::widget::ViewportNode,
window::PrimaryWindow,
};
fn main() {
App::new()
.add_plugins((DefaultPlugins, MeshPickingPlugin))
.add_systems(Startup, test)
.add_systems(Update, draw_mesh_intersections)
.run();
}
#[derive(Component, Reflect, Debug)]
#[reflect(Component)]
struct Shape;
fn test(
mut commands: Commands,
window: Query<&Window, With<PrimaryWindow>>,
mut images: ResMut<Assets<Image>>,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<StandardMaterial>>,
) {
// Spawn a UI camera
commands.spawn(Camera3d::default());
// Set up an texture for the 3D camera to render to
let window = window.single().unwrap();
let window_size = window.physical_size();
let size = Extent3d {
width: window_size.x,
height: window_size.y,
..default()
};
let format = TextureFormat::Bgra8UnormSrgb;
let image = Image {
data: Some(vec![0; size.volume() * format.pixel_size()]),
texture_descriptor: TextureDescriptor {
label: None,
size,
dimension: TextureDimension::D2,
format,
mip_level_count: 1,
sample_count: 1,
usage: TextureUsages::TEXTURE_BINDING
| TextureUsages::COPY_DST
| TextureUsages::RENDER_ATTACHMENT,
view_formats: &[],
},
..default()
};
let image_handle = images.add(image);
// Spawn the 3D camera
let camera = commands
.spawn((
Camera3d::default(),
Camera {
// Render this camera before our UI camera
order: -1,
target: RenderTarget::Image(image_handle.clone().into()),
..default()
},
))
.id();
// Spawn something for the 3D camera to look at
commands
.spawn((
Mesh3d(meshes.add(Cuboid::new(5.0, 5.0, 5.0))),
MeshMaterial3d(materials.add(Color::WHITE)),
Transform::from_xyz(0.0, 0.0, -10.0),
Shape,
))
// We can observe pointer events on our objects as normal, the
// `bevy::ui::widgets::viewport_picking` system will take care of ensuring our viewport
// clicks pass through
.observe(on_drag_cuboid);
// Spawn our viewport widget
commands
.spawn((
Node {
position_type: PositionType::Absolute,
top: Val::Px(50.0),
left: Val::Px(50.0),
width: Val::Px(200.0),
height: Val::Px(200.0),
border: UiRect::all(Val::Px(5.0)),
..default()
},
BorderColor(Color::WHITE),
ViewportNode::new(camera),
))
.observe(on_drag_viewport);
}
fn on_drag_viewport(drag: Trigger<Pointer<Drag>>, mut node_query: Query<&mut Node>) {
if matches!(drag.button, PointerButton::Secondary) {
let mut node = node_query.get_mut(drag.target()).unwrap();
if let (Val::Px(top), Val::Px(left)) = (node.top, node.left) {
node.left = Val::Px(left + drag.delta.x);
node.top = Val::Px(top + drag.delta.y);
};
}
}
fn on_drag_cuboid(drag: Trigger<Pointer<Drag>>, mut transform_query: Query<&mut Transform>) {
if matches!(drag.button, PointerButton::Primary) {
let mut transform = transform_query.get_mut(drag.target()).unwrap();
transform.rotate_y(drag.delta.x * 0.02);
transform.rotate_x(drag.delta.y * 0.02);
}
}
fn draw_mesh_intersections(
pointers: Query<&PointerInteraction>,
untargetable: Query<Entity, Without<Shape>>,
mut gizmos: Gizmos,
) {
for (point, normal) in pointers
.iter()
.flat_map(|interaction| interaction.iter())
.filter_map(|(entity, hit)| {
if !untargetable.contains(*entity) {
hit.position.zip(hit.normal)
} else {
None
}
})
{
gizmos.arrow(point, point + normal.normalize() * 0.5, Color::WHITE);
}
}

22
release-content/release-notes/viewport-node.md Normal file
View File

@ -0,0 +1,22 @@
---
title: `ViewportNode`
authors: ["@chompaa", "@ickshonpe"]
pull_requests: [17253]
---
Bevy UI now has a `ViewportNode` component, which lets you render camera output directly to a UI node. Furthermore, if the `bevy_ui_picking_backend` feature is enabled, you can pick using the rendered target. That is, you can use **any** picking backend through the viewport node, as per normal. In terms of UI, the API usage is really straightforward:
```rust
commands.spawn((
// `ViewportNode` requires `Node`, so we just need this component!
ViewportNode::new(camera)
// To disable picking "through" the viewport, just disable picking for the node.
// Pickable::IGNORE
));
```
The referenced `camera` here does require its target to be a `RenderTarget::Image`. See the new [`viewport_node`](https://github.com/bevyengine/bevy/blob/v0.17.0/examples/ui/viewport_node.rs) for more implementation details.
## Showcase
`https://private-user-images.githubusercontent.com/26204416/402285264-39f44eac-2c2a-4fd9-a606-04171f806dc1.mp4?jwt=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.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.DXec6l2SYDIpSCRssEB4o3er7ib3jUQ9t9fvjdY3hYw`