Slope Blur

Overview

Shifts and stacks the image along the slope of a height map. Rock erosion, dripping moss, rust streaks, frayed cloth — any "pattern dragged by gravity or weathering" look can be built with this single node. It is the equivalent of Slope Blur in Substance Designer.

Usage tips

• The classic wiring: noise_generate (height map) → map input, and the image you want to process → input. Feed the map with raw noise from noise_generate or a height map from height_from_image rather than the image itself — the flow looks far more natural.
• Keep distance at half the size of your pattern features or less. If the features are around 5px, start at 1–2 and increase while watching the result.
• Pick the mode by intent: erosion (spread dark streaks) → Min, light or moss (spread bright marks) → Max, a soft smeared blur → Average.
• Average accounts for alpha, so hidden RGB in fully transparent pixels does not create a colored fringe. Min / Max extremum selection and falloff remain separate behavior.
• Downhill is the direction of water and gravity. For flames or smoke crawling upward, use Uphill.

Common pitfalls

• Min/Max floods the image with a single color: distance is too large for the size of the pattern. Reduce it, or keep falloff = Linear (the default). falloff = None reproduces the legacy behavior that keeps extreme values regardless of distance and easily destroys fine patterns.
• Nothing changes: a flat (zero-gradient) map produces no flow. Connect a noise or height map with real contrast to the map input.
• Jagged streaks: increase samples for a smoother path (slightly slower).

Examples

• Weathered rock: stone texture + noise_generate (Perlin) map + mode: Min
• Moss / grime drips: dirt mask + a vertical gradient map + direction: Downhill
• Licking flames: flame sprite + noise map + mode: Max

Related nodes

• noise_generate — the go-to source for the map input (Cellular or Perlin)
• height_from_image — estimate a height map from existing pixel art
• directional_warp — for dragging in one fixed direction instead of along terrain
• gaussian_blur — when a uniform, direction-less blur is all you need