pub fn generate_mesh_base_vol_particle<'a: 'b, 'b, V>(
    vol: V,
    greedy: &'b mut GreedyMesh<'a, FigureSpriteAtlasData>
) -> MeshGen<ParticleVertex, ParticleVertex, TerrainVertex, ()>
where V: BaseVol<Vox = Cell> + ReadVol + SizedVol + 'a,