Performance issues with static colliders and bevy_ecs_tilemap

[vladinator1000]

Hi there, I added a static collider to every tile in this example from bevy_ecs_tilemap. My FPS slowed down to a crawl. Is this a known limitation to Avian when dealing with high numbers of static colliders, do I have to generate my own mesh in that case?

I have a few hundred tiles active at a time and they are constantly getting spawned/de-spawned procedurally. Here's what my scene looks like without any colliders:

2025-01-03.12-18-00.mp4

[StrikeForceZero]

im not using bevy_ecs_tilemap but im generating a grid map where all the statics are touching and ran into the same problem. if you use https://docs.rs/avian2d/latest/avian2d/collision/struct.CollisionLayers.html and just make it so the tile doesn't filter the same layer its a member of then it should improve performance. at least it did for me

[vladinator1000]

Thank you @StrikeForceZero, using collision layers fixed the performance problem ❤️

#[derive(PhysicsLayer, Default)]
pub enum CollisionLayer {
  #[default]
  Default,
  Player,
  Item,
  Ground,
}

// later when spawning tiles I added the layers like this:
 let tile_entity = commands
        .spawn((
          RigidBody::Static,
          Collider::rectangle(TILE_SIZE.x, TILE_SIZE.y),
          CollisionLayers::new(
            crate::physics::CollisionLayer::Ground,
            [
              crate::physics::CollisionLayer::Default,
              crate::physics::CollisionLayer::Player,
              crate::physics::CollisionLayer::Item,
            ],
          ),
          Transform::from_translation(world_pos.extend(0.0)),
          TileBundle {
            position: tile_pos,
            texture_index,
            tilemap_id: TilemapId(tilemap_entity),
            ..Default::default()
          },
        ))
        .id();

[Jondolf]

@vladinator1000 Have you verified with the PhysicsDebugPlugin that the tiles are actually at the correct positions? In the chunking example you linked, with a static rigid body and collider for each tile, I'm getting ~300 fps in debug mode and 1500-1700 fps in release mode, not using CollisionLayers or anything like that.

Also see StarArawn/bevy_ecs_tilemap#504 for a somewhat related issue.

[vladinator1000]

@Jondolf it does look like my tiles are touching 👀