pub fn place_foliage(
hmap: &Heightmap,
density_map: Option<&Vec<f32>>,
params: &FoliagePlacementParams,
seed: u64,
cell_size: f32,
) -> Vec<FoliageInstance>pub fn place_foliage(
hmap: &Heightmap,
density_map: Option<&Vec<f32>>,
params: &FoliagePlacementParams,
seed: u64,
cell_size: f32,
) -> Vec<FoliageInstance>