Foliage and biomes

Vegetation in Feather Engine 2 comes from three sources. Foliage layers scatter imported models and generated trees over the terrain. Tree designs are small recipes the engine turns into stylized trees. The built-in grass grows around the camera on open ground. Biomes then vary all three across the world, together with the terrain height and ground colour.

Everything is deterministic: the same settings place the same plants in the editor, in Play and in an exported game.

Scatter models with foliage layers

1. Import the models you want to scatter, such as bushes, rocks or tree models. See Assets.
2. Open Window → World & terrain → Foliage.
3. Click + Add foliage layer and tick the models it scatters. The button is available once the project has imported models.
4. Set the density, scale and slope range.

Setting	Field	Range	Description
Per 100 m²	density	0–400	Instances per 100 m²
Min scale / Max scale	scale	0.05–5 in the panel, 0.01–50 by command	Random scale range
Min slope / Max slope	min_slope, max_slope	0 (flat) – 1 (vertical)	Where the layer may grow
View distance (chunks)	view_chunks	1–8	Spawn ring in 32 m chunks; default 4
Trunk collider m	collider_radius	0–3 in the panel, 0–20 by command	0 means no collider
Keep off roads and paint	avoid_paint	On/off
Keep out of flattened areas	avoid_flattened	On/off
Cast shadows	cast_shadows	On/off
Wind sway	wind	0–3, or automatic	Automatic is 0 for models named as rocks or stones, otherwise 1
Groves	clustering	0–1; default 0	0 scatters evenly. Towards 1, instances gather in groves with open glades between, at about the same overall count
Grove size m	cluster_size	4–500 m; default 28	Shown when Groves is above 0
Placement	placement	Everywhere / Painted, by command only	Painted layers grow only where you paint them in. The panel has no control for it; set it with tree.forest or landscape.layout

To paint a layer in or out by hand, use Paint foliage and Erase foliage in the Landscape workspace. Remove foliage erases every layer, including grass, and Restore foliage brings it back.

Design trees

Tree designs are recipes: trunk, branches, canopy style and colours. Each design produces four differently shaped variants, so one design can fill a forest.

1. Open Window → World & terrain → Trees.
2. Next to New tree, click a preset: oak, birch, pine, palm, willow, cherry, autumn, dead, bush, maple, spruce, cypress, acacia, apple, ancient, sapling or berry bush.
3. Adjust the sections below. Variant previews each of the four variants, and New shape re-rolls the random seed.
4. Under On the map, set Trees per 100 m² and click Scatter all designs or Only this one. This creates or updates a foliage layer named Trees.

Section	Settings
Trunk	Height (0.3–40 m), Thickness (0.03–3 m), Taper, Lean, Bend, Roots, Size variety (0–0.6), Gnarl, Forked trunk, Bark tint, Moss and Moss colour, and a bark: Painted (built-in) or a library bark
Branches	Branches (0–12), Angle (0–120°), Length, Start, Turn up, Side branches (0–4)
Canopy	Style (Puffy, Pine, Palm, Willow, Bare, Cone or Umbrella), Clumps (1–16), Clump size (0.2–8 m), Crown width (0.3–2.5), Flatten (0–0.9), Lumpiness, Leafy edge, leaf colours, Variation, Blossom, Fruit and Fruit colour
Wind and damage	Sway (0–3), Breakable, Health, Storm breaks it above (5–60 m/s)

Setting	Field	Range	Default	Description
Size variety	size_variety	0–0.6	0.12	How different in height the four variants are
Gnarl	gnarl	0 (straight) – 1 (old and twisted)	0.25	Crooked, knotted trunk and branches
Forked trunk	trunk_fork	0–1	0	Chance the trunk splits into two leaders
Moss	moss, moss_color	0–1	0	Moss on the upper side of the bark and the roots
Side branches	twigs	0–4	2	Branches forking off each branch. Every branch end holds a leaf clump, so more side branches make more, smaller clumps and a fuller crown
Crown width	crown_width	0.3 (narrow) – 2.5 (very broad)	1	Branch reach, and the width of pine tiers and cones
Flatten	crown_flatten	0 (round) – 0.9 (flat pads)	0	Squashes the leaf clumps
Fruit	fruit, fruit_color	0–1	0	Fruit or berries in the canopy

Cone stacks clumps up the trunk into a narrow cone, as on a cypress or poplar. Umbrella spreads a flat, wide crown on spreading branches, as on an acacia. Fruit trees blossom in spring instead of fruiting.

Trees sway with the world wind, gusts and the weather. Bullets, melee swings, blasts, tornadoes and wind above the limit damage them; they shake and shed leaves, and when broken they topple as physics bodies and leave a stump. A storm limit of 60 m/s never breaks the tree.

The season changes broadleaf trees through the year; see Sky, weather and climate.

Plant a forest kit

A forest kit plants a layered forest in one step: canopy trees in groves, a few giants and an understory. In the Trees tab, click a kit next to Forest kit.

Kit	Contents
Woodland	Groves of oaks, maples and birches with glades between, a few ancient giants, and bushes, berry bushes and saplings underneath
Conifer	Dark stands of spruces, pines and cypresses, with saplings between them
Autumn	Autumn trees among birches and maples, with bushes and berry bushes underneath
Savanna	Lone acacias far apart, with clumps of bushes
Orchard	Evenly spaced apple and cherry trees, with berry bushes
Ancient	An old, mossy forest: ancient giants, oaks, willows and maples, with thick undergrowth
Tropical	Palms and maples in loose clusters, with bushes and berry bushes

A kit adds the tree designs it needs from the presets, with matching library barks when the texture library is installed. Designs you already have with the same ID are kept and used as they are. It replaces the foliage layers Trees, Giants and Understory (a layer’s Placement is kept), removes those a kit doesn’t use, and turns off Procedural trees, rocks and flowers. Tune the layers afterwards in the Foliage tab. Applying a kit is one undo step.

Grass

The built-in grass grows in a field around the camera on open terrain. It stays off roads, painted layers, rivers, flattened plots, water and the ground under buildings.

1. Open Window → World & terrain → Ambience.
2. Under Grass, pick a Preset: meadow (the default), lush, lawn, savanna, autumn, toon, alien, wildflowers, forest floor, highland or tundra.
3. Adjust Grass, Grass colour and Grass motion.

Setting	Range	Description
Amount	0–2	Density
Blade shape	Sharp / Soft / Wide
Other shapes mixed in	0–1	Share of blades in another shape, such as broad weeds among sharp blades. Default 0.15
Curvature	0–1	How far the blades arc over. Default 0.4
Soft shading	0–1	Rounded shading across each blade, from flat cards to fully rounded. Default 0.6
Field radius	10–60 m	How far from the camera grass grows
Match the ground	On/off	Takes the colour from the base terrain layer
Root shade, Variation	0–1
Sun-bleached tips, Tip colour (bleached)	0–1; sRGB	How much the top of each blade takes the bleached colour. Default 0.22
Patches, Patch size	0–1; 2–200 m	Colour patches
Sun through blades	0–2	Translucency
Trees match the grass	0–1	Generated trees take on the grass colour where they grow
Flowers	0–0.3	Share of flowering blades
Flowers in patches	0–1	0 scatters flowers evenly; 1 grows them only in patches of one colour. Default 0.6
Flower size	0.5–2.5	Flower head size. Default 1
Wind sway, Gusts	0–3; 0–2
Gust size	4–80 m	Size of the gust fronts rolling over the field. Default 18 m
Trampling, Player reach	0–2; 0.2–5 m	The player, characters, rolling bodies and blasts press trails into the grass
Stands back up in	0.2–60 s
Springy (wobbles back)	0–1	Trampled grass overshoots and wobbles as it stands up. Default 0.6
Can be cut, Grows back in	On/off; 0–600 s (0 never)	Melee swings, blasts and scripts cut it to stubble
Shots clip it	On/off	Shots hitting the ground flick the grass aside and, if it can be cut, clip a tuft. Default on
Rain weighs it down	0–1

To vary grass by hand, use the grass brushes in the Landscape workspace. Scripts use push_grass(x, y, z, radius) and cut_grass(x, y, z, radius).

Example: a cherry orchard in lush grass

You’ll design a cherry tree, scatter it over the land and switch the grass to a lush look. Start from a new project (File → New project…); it has no tree designs yet.

1. Open Window → World & terrain and select the Trees tab.
2. Next to New tree, click Cherry. A design named after the preset appears and is selected.
3. Under On the map, set Trees per 100 m² to 4 and click Only this one. This creates a foliage layer named Trees that scatters the cherry design.
4. Select the Ambience tab and, under Grass, click Lush next to Preset.
5. Fly over the meadow: cherry trees in four shapes cover the open ground, with taller, deeper green grass and flowers beneath them.

To clear a spot, open the Landscape workspace, choose Paint, pick Trees next to Foliage and use Erase foliage.

Do the same from the command line:

feather-cli --workspace ./orchard command project.create \
  --json '{"name":"Orchard"}' --save project.feather.json

feather-cli --workspace ./orchard --project project.feather.json command tree.upsert \
  --json '{"preset":"cherry","value":{"id":"cherry","name":"Cherry"}}' --save project.feather.json

feather-cli --workspace ./orchard --project project.feather.json command tree.forest \
  --json '{"trees":["cherry"],"density":4}' --save project.feather.json

feather-cli --workspace ./orchard --project project.feather.json command ambience.grass_preset \
  --json '{"preset":"lush"}' --save project.feather.json

To grow the orchard only where you paint it, create the layer as Painted and paint it in. This puts a 16 m patch of cherries at X 20, Z −10:

feather-cli --workspace ./orchard --project project.feather.json command tree.forest \
  --json '{"trees":["cherry"],"layer":"Orchard","density":4,"placement":"Painted"}' \
  --save project.feather.json

feather-cli --workspace ./orchard --project project.feather.json command landscape.stroke \
  --json '{"brushes":[{"mode":"FoliagePaint","foliage_layer":"Orchard","center":[20,-10],"radius":16,"strength":1}]}' \
  --save project.feather.json

Check it worked:

feather-cli --workspace ./orchard --project project.feather.json command tree.get
feather-cli --workspace ./orchard --project project.feather.json command tree.inspect \
  --json '{"id":"cherry"}'

tree.get lists the cherry design with "canopy": "Puffy" under trees, and a forests entry {"layer": "Trees", "trees": ["cherry"], "density": 4.0} (plus Orchard if you made it). tree.inspect generates variant 0 and reports its height, about 6 m, and its triangle counts.

Wind

Wind is a project physics setting. It sways vegetation, blows cloth and smoke, and pushes bodies. Set the wind vector in metres per second, the gust strength (0–1) and a global foliage sway multiplier (0–3) with physics.set; the weather adds to it during storms. Each foliage layer and tree design has its own sway multiplier on top. See Physics.

Level of detail

Foliage stays cheap without per-model setup:

• Instances fade out with a dithered dissolve over the last chunk of their view distance, so nothing pops in or out. Small foliage fades over a wide band; trees, bushes and rocks over a short one.
• Foliage models use at most two detail levels: full detail near the camera and one simplified level beyond it.
• Imported models carry their own detail levels as sibling nodes named <name>_LOD0, _LOD1 and so on. Each level shows within a distance band scaled to the model’s size and cross-fades into the next.
• Beyond the streamed chunks, the distant land is drawn without foliage. Areas where tree layers grow are tinted to read as forest.

Biomes

Biomes split a level into climate regions such as meadow, forest, highlands and scrub. Two noise fields, temperature and moisture, give every point a climate; each biome claims a point in that climate space, and the nearest biomes win, blended at their borders. A biome then shapes the terrain height and dresses the ground, grass and foliage, and sets footstep sounds and gameplay tags.

1. Open Window → World & terrain → Biomes.
2. Start from a set: temperate, wilderness, arid or frozen. A set replaces the biome list and points each biome at the level’s matching texture layer by name.
3. Tune the Map, then each biome. The live preview shows the blended biomes, shaded by height.
4. Add Regions to force one biome inside a disc, such as cursed lands around a castle or a safe start area.

Tip

Use the Flat landscape base for pure biome terrain. On Meadow, the biome height adds on top of the base.

Map settings

Setting	Field	Range	Default
Enabled	enabled	On/off
Seed	seed	0–9,999 in the panel
Patch size	scale	20–5,000 m in the panel, up to 50,000 by command	700 m
Border blend	blend	0 (hard) – 1 (wide)
Ragged borders	warp	0–1

Biome settings

Section	Setting	Field	Range
Climate	Temperature, Moisture	temperature, moisture	0 (cold, dry) – 1 (hot, wet)
Climate	Weight	weight	0–4; 0 means only regions place it
Terrain	Elevation	elevation	−100 to 300 m in the panel, −500 to 2,000 by command
Terrain	Hill height	relief	0–300 m in the panel, up to 1,000 by command
Terrain	Hill size	roughness	4–2,000 m in the panel, up to 10,000 by command
Terrain	Ridges	ridges	0 (rolling) – 1 (sharp)
Ground	Tint, texture layer, Layer amount	ground_color, ground_layer, ground_layer_amount	Layer 0–3; amount 0–1
Grass	Density, Height, colour	grass, grass_height, grass_color	0–2; 0.2–3
Foliage	Every layer, per-layer multipliers	foliage_default, foliage	0–4; 0 removes the layer here
Gameplay	Footstep surface, tags	surface, tags	grass, dirt, stone, wood, water, snow, metal or sand; up to 8 tags

Biome presets: meadow, forest, highlands, scrub, lakeland, snowfield, taiga and cursed. A biome’s temperature and moisture also feed the climate.

Scripts read biomes with biome_at(x, z), biome_weight(id, x, z), biome_has_tag(x, z, tag) and biomes().

Limits

• Up to 32 foliage layers per landscape, each with up to 16 models and 16 tree designs.
• Up to 16 biomes and 64 regions per level.
• Foliage view distance is at most 8 chunks (256 m).
• You cannot delete a tree design while a foliage layer scatters it, or a biome while a region places it.

Automate it

This creates an oak design, scatters it in groves, installs the temperate biome set and checks the result:

feather-cli --connect .feather-session.json command tree.upsert \
  --json '{"preset":"oak","value":{"id":"oak","name":"Oak"}}'

feather-cli --connect .feather-session.json command tree.forest \
  --json '{"trees":["oak"],"density":2,"view_chunks":5,"clustering":0.6,"cluster_size":40}'

feather-cli --connect .feather-session.json command biome.set \
  --json '{"preset":"temperate","patch":{"enabled":true,"scale":900}}'

feather-cli --connect .feather-session.json command biome.query \
  --json '{"center":[0,0],"radius":1500,"size":40}'

Command	Purpose
landscape.layout	Replaces foliage layers, among other landscape data
tree.get / tree.inspect	Reads designs; generates one to report its size and triangle counts
tree.upsert / tree.remove	Creates, edits or deletes a tree design
tree.forest	Creates or updates a foliage layer of tree designs, with optional clustering and cluster_size
tree.forest_kit	Plants a forest kit; density multiplies every layer (0.1–4, default 1) and seed reshuffles placement
tree.bark	Gives a design a library bark texture
ambience.grass_preset / ambience.set	Applies a grass preset or patches the grass settings
biome.get / biome.set	Reads biomes; sets up the biome map
biome.upsert / biome.remove	Creates, edits or deletes a biome or region
biome.query	Reports the biome at a point and returns an ASCII map of the layout
physics.set	Sets the wind, gusts and foliage sway

To plant a whole layered forest instead, with wildflower grass beneath it:

feather-cli --connect .feather-session.json command tree.forest_kit \
  --json '{"kit":"woodland","density":1.5}'

feather-cli --connect .feather-session.json command ambience.grass_preset \
  --json '{"preset":"wildflowers"}'

The tree.forest_kit response lists the layers it planted (Trees, Giants, Understory) with their densities, and designs_added names the designs it created.

See Agents & automation for connecting a live session.