9de25ad330
# Objective - Bevy now supports an opaque phase for mesh2d, but it's very common for 2d textures to have a transparent alpha channel. ## Solution - Add an alpha mask phase identical to the one in 3d. It will do the alpha masking in the shader before drawing the mesh. - Uses the BinnedRenderPhase - Since it's an opaque draw it also correctly writes to depth ## Testing - Tested the mes2d_alpha_mode example and the bevymark example with alpha mask mode enabled --- ## Showcase  The white logo on the right is rendered with alpha mask enabled. Running the bevymark example I can get 65fps for 120k mesh2d all using alpha mask. ## Notes This is one more step for mesh2d improvements https://github.com/bevyengine/bevy/issues/13265 --------- Co-authored-by: Kristoffer Søholm <k.soeholm@gmail.com>
98 lines
3.3 KiB
Rust
98 lines
3.3 KiB
Rust
//! This example is used to test how transforms interact with alpha modes for [`MaterialMesh2dBundle`] entities.
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//! This makes sure the depth buffer is correctly being used for opaque and transparent 2d meshes
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use bevy::{
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color::palettes::css::{BLUE, GREEN, WHITE},
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prelude::*,
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sprite::{AlphaMode2d, MaterialMesh2dBundle},
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};
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fn main() {
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App::new()
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.add_plugins(DefaultPlugins)
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.add_systems(Startup, setup)
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.run();
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}
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fn setup(
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mut commands: Commands,
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asset_server: Res<AssetServer>,
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mut meshes: ResMut<Assets<Mesh>>,
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mut materials: ResMut<Assets<ColorMaterial>>,
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) {
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commands.spawn(Camera2dBundle::default());
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let texture_handle = asset_server.load("branding/icon.png");
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let mesh_handle = meshes.add(Rectangle::from_size(Vec2::splat(256.0)));
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// opaque
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// Each sprite should be square with the transparent parts being completely black
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// The blue sprite should be on top with the white and green one behind it
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commands.spawn(MaterialMesh2dBundle {
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mesh: mesh_handle.clone().into(),
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material: materials.add(ColorMaterial {
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color: WHITE.into(),
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alpha_mode: AlphaMode2d::Opaque,
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texture: Some(texture_handle.clone()),
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}),
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transform: Transform::from_xyz(-400.0, 0.0, 0.0),
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..default()
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});
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commands.spawn(MaterialMesh2dBundle {
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mesh: mesh_handle.clone().into(),
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material: materials.add(ColorMaterial {
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color: BLUE.into(),
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alpha_mode: AlphaMode2d::Opaque,
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texture: Some(texture_handle.clone()),
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}),
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transform: Transform::from_xyz(-300.0, 0.0, 1.0),
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..default()
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});
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commands.spawn(MaterialMesh2dBundle {
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mesh: mesh_handle.clone().into(),
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material: materials.add(ColorMaterial {
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color: GREEN.into(),
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alpha_mode: AlphaMode2d::Opaque,
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texture: Some(texture_handle.clone()),
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}),
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transform: Transform::from_xyz(-200.0, 0.0, -1.0),
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..default()
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});
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// Test the interaction between opaque/mask and transparent meshes
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// The white sprite should be:
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// - only the icon is opaque but background is transparent
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// - on top of the green sprite
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// - behind the blue sprite
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commands.spawn(MaterialMesh2dBundle {
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mesh: mesh_handle.clone().into(),
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material: materials.add(ColorMaterial {
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color: WHITE.into(),
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alpha_mode: AlphaMode2d::Mask(0.5),
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texture: Some(texture_handle.clone()),
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}),
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transform: Transform::from_xyz(200.0, 0.0, 0.0),
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..default()
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});
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commands.spawn(MaterialMesh2dBundle {
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mesh: mesh_handle.clone().into(),
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material: materials.add(ColorMaterial {
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color: BLUE.with_alpha(0.7).into(),
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alpha_mode: AlphaMode2d::Blend,
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texture: Some(texture_handle.clone()),
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}),
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transform: Transform::from_xyz(300.0, 0.0, 1.0),
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..default()
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});
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commands.spawn(MaterialMesh2dBundle {
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mesh: mesh_handle.clone().into(),
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material: materials.add(ColorMaterial {
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color: GREEN.with_alpha(0.7).into(),
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alpha_mode: AlphaMode2d::Blend,
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texture: Some(texture_handle),
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}),
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transform: Transform::from_xyz(400.0, 0.0, -1.0),
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..default()
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});
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}
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