Vegetation · Berlenga

Biome plant placement from terrain maps; grass in the weather's wind; GPU-placed instances seen by path tracing; per-instance bones.

Plant placement (VegetationField3D, Biome, PlantSpecies): places species by spacing, footprint and rules on slope, wetness and distance to water over a TerrainDataMap3D; evenly spread, the same for a seed. 12,899 plants over 256 m place once in about 45 ms, then draw as ordinary MultiMeshes.
Placement by geology (TerrainDataMap3D.geology_source; PlantSpecies soil_depth_range, rock_range, talus_range): plants follow the generated soil, rock and scree; trees stay off bare rock and thin soil, grass thins on rock.
Density masks (density_mask, density_mask_rect; per species mask_channel, mask_invert): a painted texture thins or clears any species per channel, for clearings and paths.
Placement by climate (temperature_range, january_temperature_range, precipitation_range, aridity_range, sunlight_range): species by temperature, winter frost, rain, aridity and sunlight.
Canopy shade (canopy_radius, shade_range; weather_map): understorey placed by the shade of placed crowns; crowns feed the weather’s canopy map.
Grass (GrassField3D): blades grow round the camera in clumps, follow TerrainDataMap3D rules, thin with distance, bend in the WeatherMap3D wind and darken in rain; path traced.
Trampling (grass_trample group, GrassField3D.trample_recovery): bodies lay grass down and it springs back.
Ground cover (GrassField3D undercoat fields, view_facing; PlantSpecies patches): edge-on blades widened, ground tinted under grass, clover and flower drifts.
GPU-placed instances (RenderingServer.multimesh_mark_buffer_rd_changed()): MultiMesh records written by a compute shader reach culling, motion vectors and path tracing.
Instance bones (MultiMesh.bones_per_instance): each instance is skinned from its own records, so thousands of plants bend in the wind without a Skeleton3D each; raster and path traced. 900 swaying stems: 0.30 ms render CPU, against 5.97 ms as 900 Skeleton3D.

Images#

A valley with trees, bushes and reeds placed by biome rules, raster and path traced

Plant placement: trees on dry ground, bushes between them, reeds along the banks (placeholder meshes).

A grass carpet with undercoat, clover and flowers, raster and path traced

Grass: a full carpet, raster and path traced.

Sparse grass before, then with ground cover

Ground cover: bare ground between blades is filled with undercoat, clover and flowers.

Grass bending as gusts travel downwind, raster

Grass in wind: gusts sweep across the field downwind.

A body walking through grass that lies down and springs back, raster

Trampling: the grass lies down under the body and springs back behind it.

GPU-written MultiMesh records, path traced: before and after the call

GPU-placed instances: without the call the GPU-written instances never appear.

Stems in rest pose, then bent by instance bones in one MultiMesh, path traced

Instance bones: one MultiMesh, every stem bent by its own bones.