2 releases
0.1.1 | May 25, 2023 |
---|---|
0.1.0 | May 25, 2023 |
#1909 in Game dev
26 downloads per month
30KB
594 lines
bevy_sprite_instancing
A plugin for Bevy to render lots of instanced sprites in a single draw call.
How does the plugin work?
Instead of going through all similar entity sprites one-by-one,
the plugin provides SpriteInstancingGroup
s which can contain
Entity ID's of these sprites. The plugin then collect all these sprites'
transforms and submits them to the GPU as one large buffer, which is then
used to draw all of them at once.
Features
- Animated tiles
- Nice FPS when drawing lots of sprites (up to 1 million)
How do I use this?
For a quick example, see this example.
Here's a simple example of how to draw lots of sprites:
pub const ENTITY_COUNT: usize = 100000;
fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
// Create a camera
commands.spawn(Camera2dBundle::default());
// Load a spritesheet
let spritesheet = InstancedSpritesheet {
image: asset_server.load("textures/my_spritesheet.png"),
// Size of this spritesheet in tiles
width_tiles: 32,
height_tiles: 32,
};
// Create an instancing group for the sprites
let mut instancing_group = SpriteInstancingGroup {
entities: HashSet::new(),
};
let group_id = commands.spawn_empty().id();
// Spawn the sprites
for _ in 0..ENTITY_COUNT {
let position = Vec3::new(..., 0.0); // some random position
let scale = Vec3::new(..., 1.0); // some random size
let transform = ...; // create a transform from these
let sprite = InstancedSprite {
group_id,
texture_index: 0
};
let entity = commands.spawn((transform, sprite)).id();
instancing_group.entities.insert(entity);
}
// Attach the instancing group and its spritesheet
commands.entity(group_id).insert((instancing_group, spritesheet));
}
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_plugin(InstancedSpriteRenderPlugin)
.add_startup_system(setup)
.run()
}
What I didn't yet implement
There're some high-level features I haven't yet implemented:
- View region culling: no need to submit transforms of sprites which aren't present on screen
- GPU animations: instead of submitting a
texture_index
for each sprite, maybe it would be a nice idea to submitanim_start_index
andanim_len
through a separate instancing buffer
... and some low-level ones:
- Ability to mark a
SpriteInstancingGroup
as static (i.e. entities do not move) to avoid re-submitting its instancing data each frame
Dependencies
~33–67MB
~1M SLoC