Layers, channels and masks

The non-destructive stack: fill, paint and folder layers, eight PBR channels, mask effects and filters.

On this page 10 sections

A texture set is a stack of layers evaluated into eight PBR channel images. Source content remains editable even when preview operations use cached images: every fill value, procedural, mask, filter and paint image stays editable, and Blender's undo covers all of it.

Layer types

LayerWhat it does
FillSets a colour, value, procedural or image per enabled channel. Most smart-material layers are fills.
PaintHolds a painted image per channel. Blender's brush writes into it directly; vector strokes composite over it.
FolderGroups layers. A folder has its own opacity, blend mode and mask that apply to every child — including a substrate layer inside it.

Layers are displayed top-first and evaluated bottom-first. Use Add Layer above the list; Add Mask, Add Effect and More provide the related actions. Click a row to select the layer's content; the mask icon on the row selects its mask stack instead. Double-click a name to rename it. Delete removes a folder and its descendants; undo restores them. Duplicating a folder copies its children and their paint images.

Reordering

Press a row and drag it up or down to move the layer (a folder moves with its contents). Move the mouse sideways while dragging to change how deeply the layer nests, and press Esc to put it back. The arrow buttons under the list move one step at a time, and Parent moves the selected layer into a chosen folder. A drop is one undo step. The native list uses single selection.

Channels

Every layer can enable any of the eight channels independently: Base Color, Roughness, Metallic, Normal, Height, AO, Emission and Opacity. Each enabled channel has its own blend mode and opacity, edited in the selected-item strip above the list using Blend Channel (or in each row with the Blend and Opacity in Layer Rows preference); Use Layer Blend keeps the layer-wide setting instead. Opacity is shown as a whole percentage.

The Inspector's Edit Channel shows one selected channel at a time with its colour, value or image, the procedural source with scale, seed and detail, and the projection: UV or triplanar with scale, rotation and offset. Triplanar uses the base mesh's world positions and interpolated vertex normals through the render UV layer, so apply topology-changing modifiers first and use Refresh after moving geometry.

Blend modes cover the arithmetic and separable Photoshop-style set plus Hue, Saturation, Color and Luminosity. Normal channels additionally offer whiteout, RNM, additive and replacement normal blending — pick the intended one explicitly.

Channel filters

Filters sit below a channel's input and transform it in order. The library ships 52 operations: levels and histogram controls, Gaussian, directional and slope blur, warps, morphology, gradient map, HSL/HSV, sharpening, remapping and normal conversion/blending. Filter order matters. Pick them from the Filters asset category (they attach to the active channel, or to the mask stack when mask properties are selected) or from the channel's FILTERS list.

Masks

A mask is an ordered grayscale stack attached to a layer. Each item contributes coverage and combines with what is above it through Multiply, Add, Normal, Lighten (Max) or Darken (Min); every item has enable, invert, levels (black/white) and strength. The mask menu offers:

  • Painted masks, starting white or black. Black · Hide and White · Reveal set the brush value directly.
  • Projected fill masks from a procedural or image with UV/triplanar projection.
  • Generators: Edge Wear, Chips, Dirt, Cavity Dirt, Rust, Drips and the other mesh-aware masks, driven by baked or live geometry.
  • Baked maps from the texture set's mesh maps, including Selected Faces and Mean Curvature.
  • Scene fields that read the live scene — see scene fields.
  • Published Input and anchor references to another stack's result — see Anchors.
  • Vector Strokes, rendering a stroke key into the mask — see Vector Brush.
  • Filters that transform the accumulated mask (blur, levels, warp, …). A filter transforms the mask so far; it does not multiply a second, unrelated image over it.

The Inspector provides selection, reorder, delete, enable/invert, strength, levels and the generator controls; View Mask isolates coverage and Back to Material restores the material. Add Paint to Mask adds an editable correction over existing generators. Select a mask to add procedural sources, generators and filters to it.

Smart masks

Assets › Smart Masks lists 18 presets for edges, cavities, dust, rust, scratches and drips. Select the target layer and preset, then click Apply to add an editable effect. Replace Masks with This in the asset context menu or Assets panel explicitly replaces the stack. Map requirements are checked before application; new smart-mask effects use Normal.

Edge wear, edge size and edge width

Edge Wear uses the current curvature maps, combining sharp crease lines with smooth convex features; noise only breaks that coverage up, and raising a generator's amount never turns triangulation edges into eligible edges. The edge map bakes as four reaches from one Curvature Radius (thin ×0.5, normal ×1, wide ×2, extreme ×4) sharing the same crease lines. Each Edge Wear or Chips mask has a live Edge Size slider that blends between those maps and an Edge Width slider that narrows the chosen band; neither needs a rebake. Minimum Edge Angle decides which convex creases qualify and Edge Width (px) their texture width — these are bake settings, so rebake after changing them with Rebake Edge Map. Applying an edge-driven material, effect or smart mask before the edge maps exist queues that bake in the background, with progress in the status line; the effect updates when the maps land.

Edge Wear and Chips can also take their edges from live geometry instead of a bake; see live edges.

Baking a mask stack

Bake Mask Stack to Texture converts the selected layer's mask effects into one packed, editable grayscale UV texture. It is useful when a geometry effect or an external tool needs a stable image, at the cost of the stack's live parameters. The Shader Native preview evaluates supported masks in the material graph; export and operations requiring pixels use the CPU reference or isolated raster inputs.

For mesh selectors, nested groups, custom shader masks and painted corrections, see Advanced masks. For seam-aware filtering and sizes in metres, see Physical scale and surface filters.

Procedural sources

Fill channels and masks can use any of 65 deterministic procedural sources: 45 noise families (Perlin, Simplex, FBM, Value, Voronoi/Worley and named variants) and 20 pattern and detail sources such as grunge, scratches, cracks, fibers, grain, fingerprints and swirls. Seeds are stable for a material, layer and chosen seed, including after saving and reopening. Shader-compatible sources run in the live graph; sources that require pixels use cached raster inputs.

How the preview is evaluated

The default authoring mode is Shader Native: editable layers and masks are compiled into an internal Blender material shader graph, so supported slider edits update the viewport immediately without rasterising texture outputs. Texture baking is reserved for export, explicit snapshots and operations that need pixels (some procedural fields and spatial filters use isolated raster inputs). Initial graph construction still has a cost that grows with the material; hiding a layer or changing a value afterwards is cheap. Texture Set settings → Preview Quality offers disposable 512/1024 previews. Export and explicit full-resolution evaluation use the authored resolution; Shader Native save preserves source images without baking every output. See profiling, bypass and layer caches.

The add-on repository documents the design and its measured costs in docs/shader-preview-architecture.md.