Layer System: Paint, Mask, Filter, and Group Layers

ArmorPaint uses a non-destructive layer stack similar to professional 2D painting applications. Every stroke, fill, and effect lives on its own layer, and layers are composited together in real time using GPU shaders. You can reorder, hide, duplicate, merge, and delete layers at any time without permanently altering your base mesh. The Layers panel is available in the sidebar and can be expanded to a full 2D view via the 2D View button.

Layer Types

Paint Layer
Mask Layer
Fill Layer
Group Layer
Path Layer

The standard layer type (LAYER_SLOT_TYPE_LAYER). Stores painted texture data across up to three internal textures:

texpaint — Base color and opacity.
texpaint_nor — Normal map data.
texpaint_pack — Packed channel data: Occlusion (R), Roughness (G), Metallic (B).

Paint layers support all 11 paintable channels (base color, opacity, occlusion, roughness, metallic, normal, normal blend, height, height blend, emission, and subsurface) that can be toggled on or off per layer.

A black-and-white mask (LAYER_SLOT_TYPE_MASK) attached to a parent layer or group. White areas of the mask reveal the parent layer; black areas conceal it. Masks support opacity (mask_opacity) to control blend strength.Masks can be added as Black Mask, White Mask, or Fill Mask from the new layer menu. You can Invert or Apply a mask via the layer context menu (right-click).

A fill layer is a paint layer whose pixels are procedurally generated by assigning a material (fill_material). Rather than storing hand-painted brush strokes, the layer content is driven entirely by the material’s node graph and re-evaluated whenever the material changes.Fill layers expose UV Scale and Angle sliders in the context menu, and support all three UV types (UV Map, Triplanar, Project).

Fill layers use the assigned material’s full node graph to generate their content. Editing that material’s nodes will update the fill layer in real time. To convert a fill layer back to a static paint layer, right-click and choose To Paint Layer.

A container layer (LAYER_SLOT_TYPE_GROUP) that holds other paint layers and/or fill layers as children. Groups can be collapsed or expanded in the panel. Masks applied to a group affect all child layers simultaneously.Groups cannot currently be nested inside other groups.

A stroke-based layer that stores paint as a series of UV-space and world-space path points (path_points, path_points_world, path_points_camera) rather than rasterized pixels. Path layers can be straight or curved (path_curved) and are associated with a material (path_material) that determines their appearance.Create a Path or Curve layer from the New Layer menu (+ button in the Layers panel).

Layer Properties

Each layer slot (slot_layer_t) exposes the following configurable properties:

Visibility and Opacity

Property	Description
`visible`	Toggle the layer on/off. A hidden layer is excluded from compositing. Click the eye icon next to the layer.
`mask_opacity`	Overall opacity of the layer (0.0–1.0, displayed as 0–100%). For mask layers this controls how strongly the mask is applied to its parent.

Paint Channels

Each channel can be individually enabled or disabled per layer via the Channels section in the layer context menu (right-click on the layer):

Field	Channel
`paint_base`	Base Color
`paint_opac`	Opacity
`paint_occ`	Occlusion
`paint_rough`	Roughness
`paint_met`	Metallic
`paint_nor`	Normal
`paint_nor_blend`	Normal Blend
`paint_height`	Height
`paint_height_blend`	Height Blend
`paint_emis`	Emission
`paint_subs`	Subsurface

Channels beyond Base Color and Opacity are only active in the PBR workflow.

UV Settings

Property	Description
`uv_type`	UV projection mode: UV Map (0), Triplanar (1), or Project (2).
`uv_map`	The specific UV channel index to use (`uv0`, `uv1`, etc.) when `uv_type` is UV Map.
`scale`	UV tiling scale for fill layers (0.0–5.0). Defaults to 1.0.
`angle`	UV rotation angle for fill layers (0–360°). Defaults to 0.0.

Object Mask

The object_mask property restricts a layer’s paint contribution to a specific mesh object in the scene. Set it via the Object dropdown on the layer row. Choose Shared (index 0) to paint across all objects, or select a named object to isolate painting to that mesh.

Blending Modes

All 18 blending modes from blend_type_t are supported. Select the blending mode from the dropdown on the layer row or in the layer context menu:

Mix

Default alpha-blend compositing.

Darken

Keeps the darker of the two colors.

Multiply

Multiplies colors, always darkening.

Burn

Darkens by increasing contrast.

Lighten

Keeps the lighter of the two colors.

Screen

Inverted multiply; always lightens.

Dodge

Brightens by decreasing contrast.

Add

Adds color values together.

Overlay

Combines Multiply and Screen based on base brightness.

Soft Light

Softer version of Overlay.

Linear Light

Linear Dodge or Burn based on blend color.

Difference

Absolute difference between colors.

Subtract

Subtracts blend color from base.

Divide

Divides base color by blend color.

Hue

Applies hue from blend, keeps base saturation/value.

Saturation

Applies saturation from blend, keeps base hue/value.

Color

Applies hue and saturation from blend, keeps base value.

Value

Applies value (brightness) from blend, keeps base hue/saturation.

Right-click any layer to access its context menu. Key actions include:

Export

Export the layer’s texture to a PNG file on disk, or export the full texture set via the standard export dialog.

To Fill Layer / To Paint Layer

Convert between a procedural fill layer and a rasterized paint layer. Converting to a fill layer uses the current active material. Converting to a paint layer bakes the fill result into pixel data.

Delete / Clear / Duplicate

Delete removes the layer entirely. Clear resets all pixels to transparent (or white for masks). Duplicate (Ctrl+D) creates a copy of the layer above the original.

Merge Down

Flattens the selected layer onto the layer directly below it. Only available when a compatible layer exists below.

Apply / Invert (Masks only)

Apply bakes the mask into its parent layer and removes the mask slot. Invert flips all mask pixel values.

Undo and Redo

Action	Shortcut
Undo	`Ctrl+Z` (`edit_undo`)
Redo	`Ctrl+Shift+Z` (`edit_redo`)

The number of undo steps is configurable in Preferences → Usage via undo_steps. At very high texture resolutions (≥16384 px), the undo step count is automatically reduced to 1 to conserve GPU memory.

Getting Started

Painting

Node Editor

Rendering & Baking

Import & Export

Configuration

Layer System: Paint, Mask, Filter, and Group Layers

Layer Types

Layer Properties

Blending Modes

Mix

Darken

Multiply

Burn

Lighten

Screen

Dodge

Add

Overlay

Soft Light

Linear Light

Difference

Subtract

Divide

Hue

Saturation

Color

Value

Layer Context Menu

Undo and Redo

Build docs developers (and LLMs) love

Getting Started

Painting

Node Editor

Rendering & Baking

Import & Export

Configuration

Documentation Index

​Layer Types

​Layer Properties

​Blending Modes

Mix

Darken

Multiply

Burn

Lighten

Screen

Dodge

Add

Overlay

Soft Light

Linear Light

Difference

Subtract

Divide

Hue

Saturation

Color

Value

​Layer Context Menu

​Undo and Redo

Build docs developers (and LLMs) love

Layer Types

Layer Properties

Blending Modes

Layer Context Menu

Undo and Redo