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Documentation Index

Fetch the complete documentation index at: https://mintlify.com/armory3d/armorpaint/llms.txt

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ArmorPaint’s tool palette provides everything you need to paint, fill, clone, and transform textures directly on your 3D mesh. Tools are selected from the toolbar or via keyboard shortcuts defined in the keymap. The active tool determines how mouse input is interpreted in the 3D viewport—from freehand brush strokes to physics-based particle effects.

Tool Reference

Brush

Shortcut: BThe standard freehand painting tool. Applies the active material’s channels to the surface according to brush radius, opacity, hardness, and blending settings. Supports pen pressure, symmetry, and stencil masking.

Eraser

Shortcut: EErases painted pixels on the active layer, restoring transparency. Shares radius, opacity, and hardness controls with the Brush tool. Use swap_brush_eraser to quickly toggle between Brush and Eraser without losing your brush settings.

Fill

Shortcut: GFlood-fills a region using the active material. Four fill modes are available (see Fill Modes below). Useful for quickly blocking in colors or materials on individual faces, UV islands, or the whole object.

Decal

Shortcut: DProjects a decal texture onto the mesh surface. Hold Ctrl (decal_mask) to restrict the decal to a masked area. Press Z (decal_camera_align) to align the decal projection with the current camera view.

Text

Shortcut: TPaints text onto the mesh using the active font. The text content and font are configured in the tool options panel before stamping onto the surface.

Clone

Shortcut: LClone-stamp painting. Hold Alt (set_clone_source) and click to define the clone source point, then paint to copy that region onto another area of the surface.

Blur

Shortcut: USoftens and blurs painted areas beneath the brush. Two sub-modes are available: Blur (BLUR_TYPE_BLUR) for a standard softening effect, and Smudge (BLUR_TYPE_SMUDGE) for a smear/drag effect.

Particle

Shortcut: PPhysics-based particle painting. Particles are simulated with configurable gravity, friction, bounciness, mass, lifetime, and random variance. Paint marks are left wherever particles contact the mesh.

Color ID

Shortcut: CColor ID masking tool. Click on the mesh to pick a color ID, then paint operations are automatically restricted to areas that match that color ID. Useful when using a baked Color ID map to isolate material regions.

Color Picker

Shortcut: VSamples a color from the mesh surface and sets it as the active foreground color. After picking, the tool automatically reverts to the previously active tool (color_picker_previous_tool).

Cursor

Shortcut: RRepositions the 3D cursor in the viewport. The cursor location is used as the camera pivot point when camera_pivot is set to Cursor mode.

Select

Shortcut: MRectangular selection tool. Click and drag to define a selection region in the viewport. The selection can be used to restrict painting or other operations to a specific screen-space area.

Material

Shortcut: (unbound by default)Material picker tool. Click on the mesh surface to pick and set the material at that location as the active material. When used alongside fill layers, switching the active material also updates the fill layer’s material assignment.

Fill Modes

The Fill tool (G) supports four flood-fill modes, selectable in the tool options panel:
ModeValueDescription
ObjectFILL_TYPE_OBJECT = 0Fills the entire painted object with the active material in a single operation.
FaceFILL_TYPE_FACE = 1Fills only the individual polygon face under the cursor.
AngleFILL_TYPE_ANGLE = 2Fills all connected faces whose surface angle is within a threshold of the clicked face.
UV IslandFILL_TYPE_UV_ISLAND = 3Fills all faces belonging to the same UV island as the clicked face. UV island data is cached after the first use for performance.

UV Types

Each layer and fill operation can use one of three UV projection types:
UV TypeValueDescription
UV MapUV_TYPE_UVMAP = 0Uses the mesh’s standard UV map coordinates. Default for most painting workflows.
TriplanarUV_TYPE_TRIPLANAR = 1Projects the material from three axis-aligned planes, blending by surface normal. Ideal for meshes without UV maps or for seamless tiling.
ProjectUV_TYPE_PROJECT = 2Projects the material from the current camera perspective. Used by the Decal layer type.

Stencil Masking

A stencil image can be overlaid on the viewport to mask brush strokes. When a stencil texture is active:
  • Ctrl (hold) — stencil_transform: Enter stencil transform mode. While held, drag the stencil to reposition it, drag a corner handle to scale it, or drag the rotation handle to rotate it. The mouse wheel also adjusts stencil scale while Ctrl is held.
  • Zstencil_hide: Toggle the stencil visibility in the viewport without removing it.
The stencil position, scale, and angle are stored in brush_stencil_x, brush_stencil_y, brush_stencil_scale, and brush_stencil_angle on the context.

Brush Sizing

ActionShortcut
Interactive radius adjustF (brush_radius) — move mouse after pressing to scrub the radius
Decrease radius[ (brush_radius_decrease)
Increase radius] (brush_radius_increase)
Adjust opacity interactivelyShift+F (brush_opacity)
Adjust angle interactivelyAlt+F (brush_angle)

Brush Ruler (Straight Lines)

Hold Shift (brush_ruler) while painting to constrain strokes to a straight line. The start point of the line is set to the last known paint position, so you can click to anchor a point, release, then hold Shift and click again to draw a perfectly straight stroke between the two points.

Swap Brush / Eraser

The swap_brush_eraser shortcut (unbound by default — assign it in Preferences → Keymap) instantly toggles between the Brush and Eraser tools while preserving all other brush settings. This is faster than manually switching tools and is especially useful for detailed cleanup work.

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