Anisotropy Map Generator

Some materials have a direction. Brushed metal, satin, and hair all reflect light differently depending on which way the surface is "combed," and renderers capture that with an anisotropy map - a texture that stores a per-pixel direction. Photographing one of those is a pain, so most people fake it procedurally. That's this node's entire job: generate an anisotropy map from nothing.

It's a niche node in an already niche pack, but if you've ever needed brushed metal and reached for a stock texture, this is the faster road. It's also genuinely zero-cost: pure math, instant result, no assets.

How it works

It builds a direction field on a coordinate grid, then encodes it the way PBR renderers expect: the R and G channels store the tangent direction (cos/sin of the angle), and B stores the strength. So a "brushed" surface isn't a pile of parallel scratches - it's a directional vector map, which is exactly what the anisotropy slot of a material wants. The five pattern_type options cover the common cases:

• brushed_horizontal / brushed_vertical - uniform direction. The default starting point for metal.
• brushed_circular - angle wraps around a center. Think spun or lathe-finished metal.
• hair_flow - a wavy, sinusoidal direction field. For cloth and hair strands.
• custom_angle - you supply the exact direction in degrees via angle.

The variation slider (0–1) adds random jitter to the direction field, which is the difference between a perfect grid and something that reads as organic brush strokes. strength (0–1) scales how strongly the direction is expressed.

The inputs

width, height, pattern_type, angle (0–360, only used by custom_angle), strength, variation, and seed. Output: a single anisotropy IMAGE.

The honest caveats

This is a flat, uniform pattern generator - it can't do a mask where only part of the object is brushed, and it can't read an existing texture and figure out its flow. For a full material you'll want to mask or blend it (the pack's Multi-Texture Blender is the obvious partner), and for complex flows you'll want a hand-authored map instead. Also keep in mind that not every engine exposes anisotropy - check that your material model actually has the slot before you build the map. And the "variation" is genuinely random, so remember the seed: if you like a pattern, lock the seed or you'll chase a moving target across re-runs.

Installation

Ships in amtarr/ComfyUI-TextureAlchemy under Add Node → Texture Alchemist → Materials. Install via ComfyUI Manager (search "TextureAlchemy") or:

cd ComfyUI/custom_nodes
git clone https://github.com/amtarr/ComfyUI-TextureAlchemy

Restart ComfyUI. No dependencies, no models to download - it generates on the fly.