Advanced masks

Place detail with mesh selectors, painted corrections, nested mask groups and procedural Mask Graphs.

On this page 4 sections

Put wear on exposed edges, keep rust around screws, or paint out dirt where a character would grip an object. Combine generators, mesh selections, painted corrections and procedural graphs in one mask stack. Each source has its own strength, levels and blend operation.

Inspect and paint a correction

Select the intended layer, then its mask icon. The Inspector names the target.
Use View Mask to inspect grayscale coverage. Refresh the snapshot if it is out of date.
Click Add Paint to Mask to add a separate painted correction over the existing effects.
Follow the Inspector's instruction: paint black to remove coverage for Multiply, or white to add coverage for Add. Paint Mask starts the native brush; Finish ends it.
Choose Back to Material to restore the composed appearance.

Normal replaces coverage according to strength; Multiply restricts it; Add accumulates it; Lighten (Max) combines covered areas and Darken (Min) keeps their intersection. Smart masks add editable presets to this same stack.

Mesh masks

Choose Add Mask › Add Mesh Mask, then set Select By. Coverage is rasterized through the assigned faces' render UVs. Combine a Collection mask with Rust, for example, to restrict corrosion to objects in your Screws collection.

Select By	Coverage
Object	Assigned faces of one object.
Collection	Assigned objects in the collection, optionally including child collections.
Material	Faces using a material now or before the texture set replaced the original slot.
Vertex Group	Interpolated vertex weights from a named group.
Face Set	One sculpt face set.
Face Selection	The current selected faces of assigned meshes.
UV Island	Islands containing selected faces, or one island by index.
Normal Direction	Faces within an angle of a direction, with a soft falloff.
Geometry Attribute	A named point, face or corner attribute: scalar, integer, boolean or vector length.

Collection membership, materials, weights and geometry changes update the mask without a bake. Face-selection changes made in object mode may need entering and leaving Edit Mode to trigger an update. Portable materials retain selector names and attempt to relink them in the destination scene.

Nested mask groups

Add Mask Group creates a nested stack. Members combine first, then the group's result combines with its parent using the group's own operation, levels, strength and invert. For example, group Curvature × Noise followed by Levels, then multiply that group by a painted mask.

Adding while a group or member is selected inserts into that group. The list controls move entries into the group above, lift them out, move a group with its members, or dissolve the group in place. Disabling a group disables its entire contents. Anchors can publish partial coverage from inside groups.

Mask Graphs

Build a procedural mask from Open Painter nodes. Use noise for broad variation, cells for patches, mesh maps to follow the model and a ramp to choose which areas show through. The graph stays editable alongside the rest of the mask stack.

Choose Add Custom Graph to start with Coordinates → Noise → Ramp → Mask Output.
Click Edit Mask Graph to enter it in the Open Painter Graph editor. Press Shift+A to add nodes.
Connect the final value to Mask Output › Coverage. Adjust scale, seed and ramp stops while watching the material.
Press Tab or choose Back to Texture Set Graph to return to the full material.

Nodes	Use them for
Coordinates and Mapping	Choose UV, world position or normal coordinates; adjust scale, rotation and offset.
Noise, Cells, Pattern and Surface	Create grain, patches, scratches, patterns and other surface detail.
Mesh Map	Shape coverage with baked AO, curvature, thickness, position and other maps.
Value, Math and Mix	Combine sources, multiply coverage or set a threshold.
Ramp and Levels	Control contrast, transitions and the amount of visible coverage.

Try the Noise → Ramp, Cells → Ramp or Layered Noise → Ramp templates for a ready-made graph. Each insertion gets its own graph; select an existing graph on another Custom Graph mask to share it. The GPU engine evaluates these graphs directly, and export uses the same formulas.

Related workflows: anchors and graph connections, live scene fields and seam-aware filters. References: mesh masks and mask architecture.