mirror of
https://github.com/bevyengine/bevy
synced 2024-11-10 15:14:50 +00:00
248 lines
8.2 KiB
Rust
248 lines
8.2 KiB
Rust
//! Bevy has an optional prepass that is controlled per-material. A prepass is a rendering pass that runs before the main pass.
|
|
//! It will optionally generate various view textures. Currently it supports depth and normal textures.
|
|
//! The textures are not generated for any material using alpha blending.
|
|
//!
|
|
//! # WARNING
|
|
//! The prepass currently doesn't work on `WebGL`.
|
|
|
|
use bevy::{
|
|
core_pipeline::prepass::{DepthPrepass, NormalPrepass},
|
|
pbr::{NotShadowCaster, PbrPlugin},
|
|
prelude::*,
|
|
reflect::TypeUuid,
|
|
render::render_resource::{AsBindGroup, ShaderRef, ShaderType},
|
|
};
|
|
|
|
fn main() {
|
|
App::new()
|
|
.add_plugins(DefaultPlugins.set(PbrPlugin {
|
|
// The prepass is enabled by default on the StandardMaterial,
|
|
// but you can disable it if you need to.
|
|
// prepass_enabled: false,
|
|
..default()
|
|
}))
|
|
.add_plugin(MaterialPlugin::<CustomMaterial>::default())
|
|
.add_plugin(MaterialPlugin::<PrepassOutputMaterial> {
|
|
// This material only needs to read the prepass textures,
|
|
// but the meshes using it should not contribute to the prepass render, so we can disable it.
|
|
prepass_enabled: false,
|
|
..default()
|
|
})
|
|
.add_systems((setup.on_startup(), rotate, toggle_prepass_view))
|
|
.run();
|
|
}
|
|
|
|
/// set up a simple 3D scene
|
|
fn setup(
|
|
mut commands: Commands,
|
|
mut meshes: ResMut<Assets<Mesh>>,
|
|
mut materials: ResMut<Assets<CustomMaterial>>,
|
|
mut std_materials: ResMut<Assets<StandardMaterial>>,
|
|
mut depth_materials: ResMut<Assets<PrepassOutputMaterial>>,
|
|
asset_server: Res<AssetServer>,
|
|
) {
|
|
// camera
|
|
commands.spawn((
|
|
Camera3dBundle {
|
|
transform: Transform::from_xyz(-2.0, 3., 5.0).looking_at(Vec3::ZERO, Vec3::Y),
|
|
..default()
|
|
},
|
|
// To enable the prepass you need to add the components associated with the ones you need
|
|
// This will write the depth buffer to a texture that you can use in the main pass
|
|
DepthPrepass,
|
|
// This will generate a texture containing world normals (with normal maps applied)
|
|
NormalPrepass,
|
|
));
|
|
|
|
// plane
|
|
commands.spawn(PbrBundle {
|
|
mesh: meshes.add(shape::Plane::from_size(5.0).into()),
|
|
material: std_materials.add(Color::rgb(0.3, 0.5, 0.3).into()),
|
|
..default()
|
|
});
|
|
|
|
// A quad that shows the outputs of the prepass
|
|
// To make it easy, we just draw a big quad right in front of the camera. For a real application, this isn't ideal.
|
|
commands.spawn((
|
|
MaterialMeshBundle {
|
|
mesh: meshes.add(shape::Quad::new(Vec2::new(20.0, 20.0)).into()),
|
|
material: depth_materials.add(PrepassOutputMaterial {
|
|
settings: ShowPrepassSettings::default(),
|
|
}),
|
|
transform: Transform::from_xyz(-0.75, 1.25, 3.0)
|
|
.looking_at(Vec3::new(2.0, -2.5, -5.0), Vec3::Y),
|
|
..default()
|
|
},
|
|
NotShadowCaster,
|
|
));
|
|
|
|
// Opaque cube using the StandardMaterial
|
|
commands.spawn((
|
|
PbrBundle {
|
|
mesh: meshes.add(Mesh::from(shape::Cube { size: 1.0 })),
|
|
material: std_materials.add(Color::rgb(0.8, 0.7, 0.6).into()),
|
|
transform: Transform::from_xyz(-1.0, 0.5, 0.0),
|
|
..default()
|
|
},
|
|
Rotates,
|
|
));
|
|
|
|
// Cube with alpha mask
|
|
commands.spawn(PbrBundle {
|
|
mesh: meshes.add(Mesh::from(shape::Cube { size: 1.0 })),
|
|
material: std_materials.add(StandardMaterial {
|
|
alpha_mode: AlphaMode::Mask(1.0),
|
|
base_color_texture: Some(asset_server.load("branding/icon.png")),
|
|
..default()
|
|
}),
|
|
|
|
transform: Transform::from_xyz(0.0, 0.5, 0.0),
|
|
..default()
|
|
});
|
|
|
|
// Cube with alpha blending.
|
|
// Transparent materials are ignored by the prepass
|
|
commands.spawn(MaterialMeshBundle {
|
|
mesh: meshes.add(Mesh::from(shape::Cube { size: 1.0 })),
|
|
material: materials.add(CustomMaterial {
|
|
color: Color::WHITE,
|
|
color_texture: Some(asset_server.load("branding/icon.png")),
|
|
alpha_mode: AlphaMode::Blend,
|
|
}),
|
|
transform: Transform::from_xyz(1.0, 0.5, 0.0),
|
|
..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()
|
|
});
|
|
|
|
let style = TextStyle {
|
|
font: asset_server.load("fonts/FiraMono-Medium.ttf"),
|
|
font_size: 18.0,
|
|
color: Color::WHITE,
|
|
};
|
|
|
|
commands.spawn(
|
|
TextBundle::from_sections(vec![
|
|
TextSection::new("Prepass Output: transparent\n", style.clone()),
|
|
TextSection::new("\n\n", style.clone()),
|
|
TextSection::new("Controls\n", style.clone()),
|
|
TextSection::new("---------------\n", style.clone()),
|
|
TextSection::new("Space - Change output\n", style),
|
|
])
|
|
.with_style(Style {
|
|
position_type: PositionType::Absolute,
|
|
position: UiRect {
|
|
top: Val::Px(10.0),
|
|
left: Val::Px(10.0),
|
|
..default()
|
|
},
|
|
..default()
|
|
}),
|
|
);
|
|
}
|
|
|
|
// This is the struct that will be passed to your shader
|
|
#[derive(AsBindGroup, TypeUuid, Debug, Clone)]
|
|
#[uuid = "f690fdae-d598-45ab-8225-97e2a3f056e0"]
|
|
pub struct CustomMaterial {
|
|
#[uniform(0)]
|
|
color: Color,
|
|
#[texture(1)]
|
|
#[sampler(2)]
|
|
color_texture: Option<Handle<Image>>,
|
|
alpha_mode: AlphaMode,
|
|
}
|
|
|
|
/// Not shown in this example, but if you need to specialize your material, the specialize
|
|
/// function will also be used by the prepass
|
|
impl Material for CustomMaterial {
|
|
fn fragment_shader() -> ShaderRef {
|
|
"shaders/custom_material.wgsl".into()
|
|
}
|
|
|
|
fn alpha_mode(&self) -> AlphaMode {
|
|
self.alpha_mode
|
|
}
|
|
|
|
// You can override the default shaders used in the prepass if your material does
|
|
// anything not supported by the default prepass
|
|
// fn prepass_fragment_shader() -> ShaderRef {
|
|
// "shaders/custom_material.wgsl".into()
|
|
// }
|
|
}
|
|
|
|
#[derive(Component)]
|
|
struct Rotates;
|
|
|
|
fn rotate(mut q: Query<&mut Transform, With<Rotates>>, time: Res<Time>) {
|
|
for mut t in q.iter_mut() {
|
|
let rot = (time.elapsed_seconds().sin() * 0.5 + 0.5) * std::f32::consts::PI * 2.0;
|
|
t.rotation = Quat::from_rotation_z(rot);
|
|
}
|
|
}
|
|
|
|
#[derive(Debug, Clone, Default, ShaderType)]
|
|
struct ShowPrepassSettings {
|
|
show_depth: u32,
|
|
show_normals: u32,
|
|
padding_1: u32,
|
|
padding_2: u32,
|
|
}
|
|
|
|
// This shader simply loads the prepass texture and outputs it directly
|
|
#[derive(AsBindGroup, TypeUuid, Debug, Clone)]
|
|
#[uuid = "0af99895-b96e-4451-bc12-c6b1c1c52750"]
|
|
pub struct PrepassOutputMaterial {
|
|
#[uniform(0)]
|
|
settings: ShowPrepassSettings,
|
|
}
|
|
|
|
impl Material for PrepassOutputMaterial {
|
|
fn fragment_shader() -> ShaderRef {
|
|
"shaders/show_prepass.wgsl".into()
|
|
}
|
|
|
|
// This needs to be transparent in order to show the scene behind the mesh
|
|
fn alpha_mode(&self) -> AlphaMode {
|
|
AlphaMode::Blend
|
|
}
|
|
}
|
|
|
|
/// Every time you press space, it will cycle between transparent, depth and normals view
|
|
fn toggle_prepass_view(
|
|
keycode: Res<Input<KeyCode>>,
|
|
material_handle: Query<&Handle<PrepassOutputMaterial>>,
|
|
mut materials: ResMut<Assets<PrepassOutputMaterial>>,
|
|
mut text: Query<&mut Text>,
|
|
) {
|
|
if keycode.just_pressed(KeyCode::Space) {
|
|
let handle = material_handle.single();
|
|
let mat = materials.get_mut(handle).unwrap();
|
|
let out_text;
|
|
if mat.settings.show_depth == 1 {
|
|
out_text = "normal";
|
|
mat.settings.show_depth = 0;
|
|
mat.settings.show_normals = 1;
|
|
} else if mat.settings.show_normals == 1 {
|
|
out_text = "transparent";
|
|
mat.settings.show_depth = 0;
|
|
mat.settings.show_normals = 0;
|
|
} else {
|
|
out_text = "depth";
|
|
mat.settings.show_depth = 1;
|
|
mat.settings.show_normals = 0;
|
|
}
|
|
|
|
let mut text = text.single_mut();
|
|
text.sections[0].value = format!("Prepass Output: {out_text}\n");
|
|
}
|
|
}
|