Layers, channels and masks

Build a material one layer at a time: metal underneath, paint above it, then scratches, dirt or hand-painted detail. Each layer controls the PBR channels it contributes, and masks decide where it appears. Group related layers in folders to adjust a whole material at once.

Layer types

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. Use it to capture a finished mask for a reusable material or further brush work.

For mesh selectors, nested groups, Mask Graphs 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 71 procedural sources, including noise, cells, grunge, scratches, cracks, fibers, grain and fingerprints. Change the scale for finer or broader detail and the seed for another variation. The pattern stays consistent when you save and reopen the project.

Weathering Front, Corrosion Grain and Runoff Trails help build worn coatings, granular rust and streaks. Combine sources in a Mask Graph, or use a graph template to start with a connected material.

Live material preview

The Open Painter Engine evaluates layers and masks on the GPU and updates the texture set's channel images. Edits update the affected channels from the changed layer upward, reusing earlier results. Adjusting a slider, adding a mask or rearranging layers keeps the Blender material connected through one Open Painter Texture Set node.

To use the set in another Blender material, add that node from Shader Editor › Add › Input and select the texture set. Its Normal output includes the normal map and height bump, ready to connect to a shader. See Preview and performance for preview resolution, layer caches and profiling.