Erosion and Smoothing¶

Smooth and Erosion reshape the ground using the heights around each point, inside the layer's mask. They read across the borders of neighbouring terrains of the same target, so tiles stay seamless.

Smooth¶

The Smooth operation softens the terrain shape: each pass averages every point with its neighbours.

Iterations: How many smoothing passes to run.
Strength: How much of the smoothed result is used, from 0 to 1. The mask scales it further.
Radius: How far each pass reaches, in heightmap samples.

Note

Smoothing and erosion only change points inside the mask, and smoothing only averages points inside it. To soften the ground around a shape too, widen the mask with a Border adjustment. See Shape adjustments.

Erosion¶

The Erosion operation simulates natural weathering, giving terrain a more realistic, worn look.

Mode¶

Thermal: Material slides down slopes steeper than the Talus Angle, in degrees, softening cliffs and building up slopes at their base.
Hydraulic: Simulates rain droplets flowing downhill, picking up and dropping sediment. It carves gullies and channels. Droplets start at random points inside the mask, and stop when they leave it.

Common settings¶

Iterations: For Thermal, how many passes to run. For Hydraulic, multiplied by Droplets Per Iteration to give the number of droplets (70,000 at most).
Strength: How much of the eroded result is used, from 0 to 1. The mask scales it further.

Thermal settings¶

Talus Angle: The steepest slope, in degrees, that stays in place. Anything steeper slides down.

Hydraulic settings¶

Setting	What it does
Radius	How wide each droplet erodes around itself, in heightmap samples, 8 at most.
Seed	Changes where the droplets fall.
Inertia	How much droplets keep their direction instead of following the slope.
Rain Amount	Water carried by each droplet.
Sediment Capacity / Min Sediment Capacity	How much sediment a droplet can carry. Fast, steep, heavy droplets carry more; the minimum applies even on flat ground.
Erosion Rate / Deposition Rate	How fast droplets pick up and drop sediment.
Evaporation Rate	How much water droplets lose at each step.
Gravity	How fast droplets speed up going downhill.
Max Droplet Lifetime	How many steps a droplet lives, 128 at most.
Droplets Per Iteration	How many droplets fall per iteration.
Initial Speed	How fast droplets start.