Erosion brush docs

Prerequisites

• Purchase and install the plugin from Fab.
• Enable Unreal's Landmass plugin.
• Enable Edit Layers on your landscape actor.

Quick start

1. Go into Landscape mode in the editor.
2. Open Manage › Blueprint.
3. Add MK_ErosionBrush to your landscape.
4. Choose an erosion preset, or start tweaking the erosion values on the brush.
5. Give the landscape some height variation. The effect is driven by landscape height, so a flat landscape shows little or no erosion.
6. Add layer data. Type the name of one of your landscape's paint layers at the top of a weightmap entry, and its settings drive the effect onto that layer. The demo landscape material shows a working setup.
7. Choose a blend type for each layer, and save your settings as a preset to reuse in later projects.

Things to know

Walkthrough video

Erosion settings

These shape the erosion carved into the height.

Erosion Scale

Horizontal size of erosion features. Higher values give larger, broader gullies and ridges; lower values give finer, more detailed patterns. Think of it as the zoom level of the effect.

Erosion Strength

Overall depth and intensity of the displacement. Higher values carve deeper gullies and raise ridges more. Keep it low for subtle weathering; raise it for dramatic erosion.

Octaves

Number of erosion detail layers stacked together. More octaves add finer gully detail but cost more performance. 4–6 suits most landscapes.

Gully Weight

How strongly gullies carve in versus how much the effect spreads across slopes. Higher values give deeper, more pronounced channels; lower values spread erosion more evenly.

Detail

How quickly fine-detail octaves fade out on flat areas. Lower values keep fine erosion to steep slopes; higher values let it appear on gentle slopes too.

Gain

How much each octave contributes relative to the previous one. At 0.5 each octave is half the strength of the last. Lower values let large features dominate; higher values favour fine detail.

Lacunarity

How much frequency increases per octave. At 2.0 each octave is twice the frequency of the last. Higher values add very fine detail quickly; lower values keep octaves closer in scale.

Resolution Multiplier

Scales the internal texture resolution used for erosion. Higher values give more precise slope detection at a performance cost. Match it to your landscape resolution for best results.

Noise Scale

Offsets the base frequency of the Phacelle noise independently of Erosion Scale. Lower values give broader noise features; higher values give finer patterns. Use it to tune the pattern without changing the overall scale.

Cell Scale

Size of the internal Phacelle cells relative to the stripe width. Lower values give short, fragmented gullies with a rocky feel; higher values give long, unbroken channels that run further downhill.

No settings match.

Weightmap settings

Each weightmap entry paints one landscape layer from an erosion mask.

Weightmap Name

The name of the landscape layer this entry paints. It must match one of your landscape's layer names.

Enable Layer

Turns this layer on or off. When off, the layer gets no paint and keeps its current values.

Effect

Which erosion output drives this layer.

SlopeRidgeDepositionAltitude mask

Blend Type

How the mask is applied. Add blends on top of existing values, Replace overwrites them, Multiply scales them by the mask.

Erosion Splat Strength

Overall intensity of the mask on this layer. At 0 the layer gets no paint; at 1 the full mask is applied.

Erosion Offset

Shifts the mask value up or down before it's applied. Use it to grow or shrink the painted area without changing its shape.

Normalization

Consistency of the Phacelle noise output. Lower values allow more variation in gully intensity; higher values make the pattern more uniform.

Sample Step

Distance in texels between height samples used for slope. Higher values smooth quantization artifacts and broaden slope detection; lower values are more precise but noisier.

Octaves

Detail layers used for this layer's mask. More octaves add finer detail to the painted edges.

Gain

Amplitude falloff per octave for this mask. Lower values let large features dominate the painted area.

Lacunarity

Frequency increase per octave for this mask. Higher values add finer edge detail sooner.

Resolution Multiplier

Sampling resolution for this mask. Match it to your landscape resolution for accurate results.

Mask Slope

Enables slope masking. The layer is only painted where the slope is inside the set range.

Slope Mask Strength

Intensity of the slope mask. Higher values make the cutoff sharper and more dominant.

Slope Mask Scale

Coverage threshold. Lower values include gentle slopes; higher values restrict paint to steep slopes.

Slope Mask Falloff

Softness of the slope mask edge. Lower values feather the transition; higher values give a hard cutoff.

Invert Slope Amount

Offsets and inverts the slope mask. At 0 steep slopes are white; at 1 flat areas are white. Values in between create bands or outlines at specific slope angles.

Mask Altitude

Enables altitude masking. The layer is only painted inside the set height range.

Invert Altitude Mask

Flips the altitude mask, so you can paint valley floors instead of peaks with the same settings.

Altitude Mask Strength

Intensity of the altitude mask. Higher values make the height cutoff sharper and more dominant.

Altitude Offset

Moves the painted band up or down the landscape without changing its shape.

Altitude Distance

Range of heights that get full paint. Larger values paint a wider band; smaller values a narrow one.

No settings match.

Support

Found a bug or need help? Contact Michael Kinsey through the Fab listing's support link.

Changelog

v1

First release on Fab.