This example is running in WebGL2 and should work in most browsers. You can check the WebGPU examples here.
render_ui_to_texture.rs:
//! Shows how to render UI to a texture. Useful for displaying UI in 3D space.
use std::f32::consts::PI;
use bevy::{
color::palettes::css::GOLD,
prelude::*,
render::{
camera::RenderTarget,
render_resource::{
Extent3d, TextureDescriptor, TextureDimension, TextureFormat, TextureUsages,
},
},
};
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_systems(Startup, setup)
.add_systems(Update, rotator_system)
.run();
}
// Marks the cube, to which the UI texture is applied.
#[derive(Component)]
struct Cube;
fn setup(
mut commands: Commands,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<StandardMaterial>>,
mut images: ResMut<Assets<Image>>,
) {
let size = Extent3d {
width: 512,
height: 512,
..default()
};
// This is the texture that will be rendered to.
let mut image = Image {
texture_descriptor: TextureDescriptor {
label: None,
size,
dimension: TextureDimension::D2,
format: TextureFormat::Bgra8UnormSrgb,
mip_level_count: 1,
sample_count: 1,
usage: TextureUsages::TEXTURE_BINDING
| TextureUsages::COPY_DST
| TextureUsages::RENDER_ATTACHMENT,
view_formats: &[],
},
..default()
};
// fill image.data with zeroes
image.resize(size);
let image_handle = images.add(image);
// Light
commands.spawn(DirectionalLightBundle::default());
let texture_camera = commands
.spawn(Camera2dBundle {
camera: Camera {
// render before the "main pass" camera
order: -1,
target: RenderTarget::Image(image_handle.clone()),
..default()
},
..default()
})
.id();
commands
.spawn((
NodeBundle {
style: Style {
// Cover the whole image
width: Val::Percent(100.),
height: Val::Percent(100.),
flex_direction: FlexDirection::Column,
justify_content: JustifyContent::Center,
align_items: AlignItems::Center,
..default()
},
background_color: GOLD.into(),
..default()
},
TargetCamera(texture_camera),
))
.with_children(|parent| {
parent.spawn(TextBundle::from_section(
"This is a cube",
TextStyle {
font_size: 40.0,
color: Color::BLACK,
..default()
},
));
});
let cube_size = 4.0;
let cube_handle = meshes.add(Cuboid::new(cube_size, cube_size, cube_size));
// This material has the texture that has been rendered.
let material_handle = materials.add(StandardMaterial {
base_color_texture: Some(image_handle),
reflectance: 0.02,
unlit: false,
..default()
});
// Cube with material containing the rendered UI texture.
commands.spawn((
PbrBundle {
mesh: cube_handle,
material: material_handle,
transform: Transform::from_xyz(0.0, 0.0, 1.5)
.with_rotation(Quat::from_rotation_x(-PI / 5.0)),
..default()
},
Cube,
));
// The main pass camera.
commands.spawn(Camera3dBundle {
transform: Transform::from_xyz(0.0, 0.0, 15.0).looking_at(Vec3::ZERO, Vec3::Y),
..default()
});
}
const ROTATION_SPEED: f32 = 0.5;
fn rotator_system(time: Res<Time>, mut query: Query<&mut Transform, With<Cube>>) {
for mut transform in &mut query {
transform.rotate_x(1.0 * time.delta_seconds() * ROTATION_SPEED);
transform.rotate_y(0.7 * time.delta_seconds() * ROTATION_SPEED);
}
}