Masks & generators

A mask controls where a layer shows. Paint it by hand, or drive it procedurally with generators and filters — for instant edge wear, cavity dirt, and more.

Mask basics

Adding a mask

Add a mask to any layer. The mask is grayscale: white shows the layer, black hides it, grays are partial.

A layer with a mask thumbnail

The mask stack

A mask isn't just one image — it's a small stack of entries evaluated top-to-bottom, so you can combine procedural and hand-painted input:

EntryWhat it adds
PaintHand-painted grayscale (brush / fill directly on the mask).
FillDrive the mask from a single bake or image — drag it onto the source box ( to clear). The mask's simplest source; added via Add Generator ▸ Fill.
GeneratorA procedural mask from the mesh — see Generators.
FilterAdjusts the result so far — see Filters.
AnchorMarks a point in the stack that other entries can reference (advanced).
Each entry has its own blend mode and opacity against the result so far, so you can layer a hand-painted touch-up on top of a generator, for example.

Generators

Generators build a mask procedurally from your mesh and its baked maps — so edge wear, cavity dirt, and dust appear automatically. Most read a baked map, so bake first.

GeneratorWhat it masksReads
Curvature WearExposed edges and peaks — for edge wear, chipping, scratches.Curvature bake
AO CavityCrevices and recesses — for grime in cavities.AO bake
ThicknessThin vs. thick areas — e.g. wear that favours thin edges.Thickness bake
SlopeFaces by their angle to a reference axis — e.g. dust on upward-facing surfaces.World-normal bake
PositionWorld-space position — e.g. a height-based gradient.Position bake
LightA mask from a freely-aimed virtual light (azimuth + elevation) — top-down dust, directional wear.World-normal bake
Color SelectionReveal areas whose ID-map colour matches a picked colour (within a tolerance).ID map bake
FillUse any baked map or imported image as the mask — drag it onto the source box ( to clear), with a tiling/rotation transform plus gain/offset/invert. This is the mask's single-source fill.chosen source
GIF: adding a Curvature Wear generator to a mask

Filters

A filter adjusts whatever is below it in the stack — use them to refine a mask (or colour content).

FilterWhat it doesAvailable on
LevelsRemap black/white points and gamma — tighten, soften, or invert the range.Masks & colour
BlurSoften the mask. The surface blur is seam-aware (no UV-seam artifacts).Masks
SharpenBoost local contrast / crisp up edges.Masks
HSLHue / Saturation / Lightness adjust, for colour content.Colour
KuwaharaPainterly, edge-preserving smoothing.Colour
The Add-Effect menu only offers filters that make sense for the target: Blur and Sharpen need a varying grayscale signal so they're mask-only; HSL and Kuwahara are colour-only; Levels works on both.

On a grayscale mask, an HSL filter has no hue or saturation to act on, so it collapses to a brightness-and-contrast adjustment (the Lightness slider brightens or darkens). This is why HSL is offered on colour content rather than masks.

Screenshot: a Levels filter on a mask