pub fn generate_mesh<'a>(
    vol: &'a VolGrid2d<TerrainChunk>,
    (range, max_texture_size, _boi): (Aabb<i32>, Vec2<u16>, &'a BlocksOfInterest)
) -> MeshGen<TerrainVertex, FluidVertex, TerrainVertex, (Aabb<f32>, TerrainAtlasData, Vec2<u16>, Arc<dyn Fn(Vec3<i32>) -> f32 + Send + Sync>, Arc<dyn Fn(Vec3<i32>) -> f32 + Send + Sync>, AltIndices, (f32, f32))>