Terrain-Aware Constraints

Nature doesn't put trees on cliffs. Constraints enforce reality's rules so your scatter looks right.

How Constraints Work

Every candidate scatter point is tested against all active constraints using AND logic. A point must pass every constraint to survive. Fail one, and it's rejected. This is how you keep trees off cliffs, rocks out of water, and flowers below the treeline.

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Constraint visualization — slope and height filters applied to scatter

Recommended: 1920×1080

Constraint Types

Slope Constraint

Rejects points where the terrain slope exceeds a maximum angle. Computed via 3-point gradient sampling — flat ground is 0°, a vertical cliff is 90°. Trees on a 45° slope look wrong. Set maxDegrees: 30 and they stay on walkable ground.

{
  "type": "slope",
  "maxDegrees": 30
}

Height Constraint

Rejects points below a minimum height or above a maximum height. Use this to keep vegetation out of water (min height above sea level) or below the snow line (max height below peaks).

{
  "type": "height",
  "minHeight": 0,
  "maxHeight": 100
}

Exclusion Zone

Defines a circular area where nothing can be placed. Use this for building clearances, paths, sacred areas, or any region you want to keep clear. Points inside the circle are rejected.

{
  "type": "exclusion",
  "center": [50, 50],
  "radius": 20
}

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Exclusion zone — circular clearance around a building

512×512

Density Falloff

Not a hard reject — instead, this constraint modulates placement probability based on distance from a center point. Objects are dense near the center and thin out toward the edges. Perfect for biome transition zones where forest gradually gives way to grassland.

{
  "type": "density_falloff",
  "falloffCenter": [0, 0],
  "falloffRadius": 100
}

Constraint Parameters

Constraint	Parameter	Default	Description
Slope	`maxDegrees`	45	Maximum terrain angle in degrees (0–90)
Height	`minHeight`	-∞	Minimum terrain height for placement
Height	`maxHeight`	∞	Maximum terrain height for placement
Exclusion	`center`	[0, 0]	Center of exclusion circle [x, z]
Exclusion	`radius`	10	Radius of exclusion circle in world units
Density	`falloffCenter`	[0, 0]	Center of density gradient [x, z]
Density	`falloffRadius`	100	Distance at which density reaches zero

Cross-Layer Exclusion

Beyond per-point constraints, Landscaper supports cross-layer exclusion — where placed objects from one layer become exclusion zones for another. Buildings placed first? Trees avoid them automatically.

This works via a spatial hash grid. When a higher-priority layer places its instances, those positions are registered. Lower-priority layers check the grid and reject candidates within minDistance of any previously placed object.

{
  "id": "trees",
  "priority": 10,
  "excludesLayers": ["buildings", "roads"],
  "minDistance": 5
}

✅ Pro Tip

Stack constraints to create realistic biomes. A forest layer with slope < 30°, height 10–80, and density falloff from center creates a natural-looking tree line that thins toward peaks and avoids steep terrain.

Evaluation Pipeline

Generate candidates — Algorithm produces 2D points (x, z)
Cross-layer exclusion — Remove candidates near higher-priority placements
Per-point constraints — Test each surviving candidate against slope, height, exclusion
Density filtering — Apply falloff probability to remaining candidates
Sample terrain — Get Y height for each placed point