Contents

Axiom 5.4.1

User Manual — Minecraft Block Editor by Moulberry — Requires Fabric + Minecraft 1.21+


Overview

Axiom is a client-side Minecraft mod that turns the game into a real-time block editor. It sits on top of normal Minecraft: you can toggle a full editor overlay, use in-hand tools without ever opening the overlay, or flip on capability modifiers that change how vanilla placement behaves.

30+editing tools
28batch operations
10capabilities
40+keybinds
13mask node types
unlimitedundo history
Editor UI

Full-screen dockable overlay with tools panel, palette, clipboard, history, blueprint browser, world properties, and more. Toggle it with a keybind at any time.

Builder Tools

In-hand editing operations from the hotbar: move, clone, stack, mirror, smear, erase — no overlay needed.

Capabilities

Toggle-able modifiers: angel placement, infinite reach, no-clip, replace mode, bulldozer, no updates, and more.

Fig 1. Tool count by category

Editor UI

Press the Toggle Editor UI keybind to enter or exit the editor overlay. Your cursor is freed from the game and the editor camera takes over. Press it again to return to vanilla Minecraft.

Camera Controls

ActionDefault
Rotate cameraRMB
Arcball / orbit around a pointAlt + RMB
Pan cameraAlt + LMB
Crosshair camera (lock cursor to centre)MMB
Move (fly)WASD + Space / Shift
SprintLeft Ctrl
Use active toolLMB
Adjust tool radiusCtrl + Scroll

Windows

All windows are dockable, resizable, and individually toggleable from the Window menu.

Tools
Tool picker grid. Click to switch; each tool has a keybind slot.
Tool Options
Settings for the currently active tool (radius, mode, noise params, etc.).
Active Block
The block currently being painted. Includes a block-property editor.
Palette
Custom block categories. Nest, reorder, rename, add/remove blocks. Includes recently used.
History
Full undo stack with named entries. Click to rewind; right-click to preview.
Clipboard
Shows current clipboard (block/entity counts) and paste options.
Blueprint Browser
File browser for .blueprint files. Supports folders, tags, upload to server.
Target Info
Block name, coordinates, distance, and biome under the cursor.
World Properties
In-editor gamerule controls (time, weather, drops, gravity, etc.).

The Style Editor (Window menu) gives full control over UI colours, sizes, and rounding. Export/import themes via clipboard.

Viewports

Axiom supports up to 9 named editor viewports. Switch between them with Ctrl+1 through Ctrl+9. Each viewport can be pinned to a specific world location.

Multiple Viewports

Switch viewport 1-9Ctrl+1Ctrl+9
Create new viewWindow > New View
Pin to locationRight-click viewport tab

Selection System

Axiom uses a voxel boolean selection — a set of individual blocks that can be accumulated, subtracted, or intersected. Once you have a selection, operations, clipboard actions, and builder tools all respect it.

Selection Modes

Add
Unions new region with existing selection
Subtract
Removes new region from existing selection
Intersect
Keeps only the overlap between existing and new region
Replace
Discards existing, starts fresh from new region

Selection Workflow

flowchart TD
  A([Choose Selection Tool]) --> B{Selection Mode}
  B -->|Add| C[Union with existing]
  B -->|Subtract| D[Remove from existing]
  B -->|Intersect| E[Keep overlap only]
  B -->|Replace| F[Start fresh]
  C & D & E & F --> G([Active Selection])
  G --> H1[Operations\nFill / Replace / Hollow / Drain / Smooth]
  G --> H2[Builder Tools\nMove / Clone / Stack / Mirror / Smear]
  G --> H3[Clipboard\nCopy / Cut / Paste]
  G --> H4[Modify Selection\nExpand / Shrink / Smooth / Distort]
        
drag to pan · scroll to zoom
Fig 2. Selection workflow: choose a tool, set mode, accumulate blocks, then act.

Selection Tools

ToolHow It WorksKey Options
Box Select Drag to define a rectangular region between two corners. Gizmo handles allow fine-tuning after drawing. Can also be set to Position + Size mode instead of Pos1/Pos2 corners. Shrink to fit (trims air); create Marker Region
Magic Select Click a block; flood-fills and selects all connected blocks that match by your chosen comparison. Like a 3D paint-bucket selection. Comparison: Block, BlockState, Material, Solid, Any; range limit
Freehand Select Paint over blocks to include them in the selection. Works like a brush. Brush radius
Lasso Select Draw a 2D polygon outline on screen; Axiom projects it into 3D space and selects all blocks within it. Depth (how far into the screen), include non-solid blocks

Modifying a Selection

Use the Select menu after creating a selection:

ModifierEffect
ExpandGrows selection outward by N blocks in all directions
ShrinkContracts selection inward by N blocks
SmoothRounds the edges of the selection shape
DistortApplies noise to the selection boundary for organic edges
FilterRestricts selection to blocks matching a mask
Bounding BoxReplaces selection with its axis-aligned bounding box
ClearDeselects all blocks

Painting Tools

Painting tools apply blocks via a spherical (or configurable-shape) brush. They work in real time as you click and drag.

ToolDescriptionNotable Options
Painter Standard spherical brush that paints blocks. Supports soft-edge falloff and merge-strokes to smooth continuous drags. Modes: Active Block, Tiled Clipboard, Stamped Clipboard, Gradient; inner radius (hollow core)
Gradient Painter Paints blocks as a gradient between two anchored positions. The position-to-block mapping follows a configurable curve. Linear / Sphere gradient; Bezier / Linear / Nearest interpolation; lock Pos1 / Pos2
Biome Painter Paints biome data onto the world. Can fill the entire vertical column at each position. Optionally visualises biomes with colour overlay. Fill vertically; biome visualisation toggle
ToolDescriptionNotable Options
Noise Painter Each block under the brush is placed or skipped probabilistically based on a noise function value at that position. Creates natural-looking irregular fills. Noise types: Simplex, White, Splatter, Voronoi Edges, Worley, Metaball; octaves, scale, lacunarity, gain, jitter; 3D mode; anisotropic mode

Noise Painter is the go-to for organic texturing — for example, scattering gravel across a stone floor or adding moss patches to walls.

Noise type quick reference
Simplex - smooth gradient noise, good for terrain overlay White - random per-block, pure salt-and-pepper Splatter - clustered blobs, good for moss / lichen Voronoi - cell edges highlighted, good for cracked rock Worley - inverse voronoi, rounded cell interiors Metaball - smooth organic blobs merging together
ToolDescriptionNotable Options
Script Brush Runs user-written Lua scripts as a brush. The script receives block position and context, and returns what to place. Enables any custom logic that the built-in tools cannot express. Lua script editor; custom numeric / boolean parameters exposed to the script

Scripts are saved and can be shared as plain .lua files.


Sculpting Tools

Sculpting tools manipulate existing block surfaces rather than painting new blocks over them.

Surface Sculpting

ToolDescriptionNotable Options
Sculpt Draw Pulls blocks outward or pushes them inward along the surface normal. Think of it as clay sculpting — drag to add or remove material. Invert direction; mask Y axis; strength; denoise pass
Rock Tool Places rock-like organic formations at the cursor with noise-driven surface variation. Each click grows a natural-looking boulder. Meld strength, noise radius, noisiness, smoothing (sigma)
Weld Merges adjacent surfaces — fills gaps and smooths junctions between separate block masses. Strength, threshold
Melt Inverse of Weld — erodes block surfaces inward, thinning edges and removing small protrusions. Strength, threshold
Extrude (sculpt) Expands or shrinks a one-block-thick surface shell. Displace mode moves the surface instead of duplicating it. Mode: Expand / Shrink / Displace

Drawing & Path Tools

ToolDescriptionNotable Options
Freehand Draw Drag the mouse through 3D space to place blocks along the drawn path. Brush radius
Path Place a series of control points; Axiom draws a smooth tube or corridor through them. Automatically uses stairs and slabs on diagonal runs. Curve types: Bezier, Catmull-Rom, Catenary, Bresenham Line, DDA Line; easing; looped / inverted; extend to ground
Text Renders text as placed blocks in the world. Choose font (including a built-in pixel font), size, direction, and rasterisation mode. Font; size; direction (all 6 faces); full-cube mode
Stamp Scatters saved blueprints randomly across a surface. Each blueprint has its own placement probability. Per-blueprint chance; min spacing; random yaw / flip; extend foundation to ground; deferred vs immediate placement
Floodfill Fills an enclosed hollow space with a chosen block — a 3D paint bucket. Target block
Fluid Ball Places a sphere of simulated fluid at the cursor. Radius; fluid type

Mesh Modelling

ToolDescription
Modelling Freeform 3D mesh editing via moveable control-point gizmos. Move individual vertices in world space to deform a block mesh. Supports full undo.
Generator Places organic tree forms (Ash, Cyprus types) at the clicked location with natural variation.

Terrain Tools

Terrain tools work on height and surface topology. They operate like a heightmap editor layered on top of the block grid.

ToolDescriptionModes / Key Options
Elevation Raises or lowers terrain under the brush. Clicking continuously keeps raising/lowering; apply-once mode makes a single change per click. Raise, Lower, Flatten, Flatten Up; Y limit; falloff; rate; smoothing; dynamics; load custom heightmap image
Slope Click two points; Axiom grades the terrain between them to form a smooth ramp. Shape: Cone or Plane
Smooth Blurs terrain height values under the brush to remove sharp spikes and jagged edges. Stable / Grow / Melt modes; strength; block ratio; fix edges
Distort Displaces blocks using a noise vector field. Creates organic wrinkled or turbulent terrain. Per-axis distance control; scale; iterations; smooth edges
Roughen Adds or removes surface micro-detail (small bumps and divots). Add / Remove mode; ratio; min exposed faces
Blend Softens the transition between different block types at their borders. Spread / Warp modes; spread distance; spread power; falloff
Shatter Fractures a region into irregular noise-edged shards, as if a rock cracked. Axis: X / Y / Z / 3D; scale; width; use active block for shard fill

The Clentaminator tool (via server-side API) converts terrain biomes: sets ground type (Grass, Dirt, Sand, Gravel, Stone), adds vegetation, and controls farmland moisture and ocean-floor fertility.


Shape Tool

The Shape tool places geometric primitives. Select a category and shape in Tool Options, then click (or click-and-drag) to place. A live preview appears before you confirm.

Three-dimensional filled or hollow volumes:

Sphere
Supersphere
Cuboid
Cube
Cylinder
Supercylinder
Cone
Pyramid
Torus
Capsule
Tube
Octahedron
Dodecahedron
Icosahedron
Metaball

Two-dimensional surfaces placed in 3D space:

Disk
Plane
Regular Polygon
Triangle Fan
Triangle Strip
Archimedean Spiral

Control-point driven surface patches:

Convex Hull
Bezier Surface
Flat Surface
Catmull-Rom Surface
Smart Surface

Smart Surface shows a live mesh wireframe overlay as you edit control points.

Shape Options (all shapes)

OptionEffect
HollowPlaces only the shell, leaving the interior empty
Separate X/Z (or H/V)Unlocks horizontal and vertical dimensions independently
Rotation mode: Auto / Keep / ResetControls whether rotation carries over between placements
Pivot: Base / CentreSets whether you place from the bottom or the centre of the shape
Gizmo space: Global / LocalWhether rotation handles align to world axes or the shape's own axes
Extrude point (E)Extrudes the nearest control point outward while placing

Utility Tools

ToolDescription
Ruler Click to place measurement points. Axiom shows Euclidean distance, Manhattan distance, bounding box dimensions, yaw, and pitch between each segment. You can split a segment, jump to the midpoint, and keep multiple rulers active at once.
Annotation Places a named text label at a world position. All annotations are listed in the Annotations window and can be shown or hidden as an overlay.

Operations

Operations apply a batch transformation to the current selection. Access them from the Operations menu or via keybind. Most open a settings dialog before executing. After every operation an undo entry is created.

Quick shortcuts: Ctrl+F Quick Fill, Ctrl+R Quick Replace — these use the last-used settings and skip the dialog.

Operation ↕ Category ↕ What It Does
FillFillFills the entire selection with the chosen block
Fill OutlineFillFills only the outer edge faces of the selection bounding box
Fill TopFillFills only the topmost layer of the selection
Fill BottomFillFills only the bottommost layer
Fill WallsFillFills the four vertical sides of the selection box
Fill NearestFillReplaces every air block with its nearest non-air neighbour (closes gaps)
Fill GapsFillFills enclosed interior gaps
Fill UnreachableFillFills all positions not reachable from outside the selection by flood-fill
ReplaceReplaceReplaces one block type with another throughout the selection
Type ReplaceReplaceSmart material-aware replace: maps block shapes across materials (e.g. any stair becomes the active block's stair type)
HollowStructureRemoves all interior blocks, leaving only the shell
DrainStructureRemoves all liquid blocks in the selection
WaterlogStructureWaterloggs all eligible blocks in the selection
GravityStructureSimulates block gravity for all falling-block types in the selection
Set BiomeStructureOverwrites the biome for all blocks in the selection
SmoothModify SelectionRounds the edges of the selection shape
DistortModify SelectionApplies noise to the selection boundary for organic edges
ExpandModify SelectionGrows selection outward by N blocks
ShrinkModify SelectionContracts selection inward by N blocks
FilterModify SelectionRestricts selection to blocks that pass a mask
Bounding BoxModify SelectionReplaces selection with its axis-aligned bounding box
ClearModify SelectionDeselects all blocks
AnalyzeAnalysisCounts and lists block-type distribution within the selection
AutoshadeAnalysisApplies ambient occlusion and sun shading using the palette block colours. Options: AO, Global Illumination, Sun Shading, Dither, palette filtering
Generate Colour FieldAnalysisGenerates a colour-gradient field within the selection volume
Animated RebuildSpecialReplays construction history as a time-lapse animation
Trigger UpdatesSpecialFires neighbour block updates for all blocks in the selection
Trigger Updates & TickSpecialFires neighbour updates and a block tick for all blocks

Builder Tools

Builder Tools operate without the Editor UI overlay. Assign the Builder Tool to a hotbar slot, select it, then use the actions below. The current selection is shown as a highlight in the world. All actions create undo entries.

ActionWhat It DoesScroll Wheel
Move Picks up and moves the selected region. Click to confirm the new position. The original blocks are deleted. Adjusts move offset / direction
Clone Places a copy of the selection at the target location. Original stays in place. Repositions clone offset
Erase Removes blocks. Sub-modes: Delete (single click removes one block), Erase Box (drag a rectangle), Erase Connected (flood-fill delete).
Stack Repeats the selection in a direction N times, placing copies end-to-end. Adjusts repetition count / direction
Smear Stretches blocks in a direction, dragging their column along as you scroll. Extends smear distance
Mirror Reflects the selection across a chosen axis. Supports X, Y, and Z.
Extrude Extrudes a face of the selection outward by one layer at a time.
Setup Symmetry Places a symmetry plane in the world. All subsequent block edits are automatically mirrored. Supports flip, rotate, and nudge of the plane. Deactivates beyond a configurable range.

Builder Tool Tips

Middle Click
Configurable as Extend Select (grow selection from current) or Magic Select (flood-fill select the targeted block type).
Axis Lock
Hold X, Y, or Z to lock the scroll direction to that axis only.
Symmetry Icon
A small icon appears in the HUD when symmetry is active, reminding you that placements are being mirrored.

Capabilities

Capabilities are toggle-able modifiers to normal Minecraft behaviour. Toggle each via the Context Menu (hold or tap Alt) or a dedicated keybind. Active capabilities are shown in the HUD.

CapabilityEffect When On
Angel Placement Place blocks in mid-air without needing an adjacent support surface.
Bulldozer Hold left-click to break blocks continuously at high speed. Great for clearing large areas.
Fast Place Place blocks much faster than vanilla allows while still maintaining precise control over which block is placed.
Force Place Bypasses all block placement restrictions (entity collisions, block limits, placement rules).
Infinite Reach Removes the block interaction distance limit. Configurable maximum reach in blocks, or truly unlimited.
No Clip Move through solid blocks while flying. Requires flight mode to be active.
Phantom Move through blocks without triggering them: pressure plates, tripwires, and sensors are not activated.
No Updates Suppress neighbour block updates when placing or breaking blocks. Allows unsupported blocks: sand mid-air, floating torches, etc.
Replace Mode Right-clicking a block replaces it with the held block instead of placing adjacent. Combine with Type Replace to preserve block shape (e.g. replace any stair material while keeping the stair orientation).
Tinker Right-clicking with an empty hand activates quick interaction: set block states, toggle doors/levers, inspect block properties.

Block Attribute Helpers

These are visual-only overlays, not persistent world changes:

HelperWhat It Shows
Show Collision MeshRed outline around block collision boxes
Show Light BlocksMakes otherwise invisible light-source blocks visible and clickable
Show Structure Void BlocksRenders structure void blocks in-world
Expand Hitboxes to Full CubeMakes small blocks (buttons, torches) easier to click
Make Fluid Hitboxes SolidAllows clicking on fluid surfaces to destroy or place blocks on them
Prevent InteractionsPrevents opening containers, doors, and signs while holding a block

Clipboard & Blueprints

Clipboard

The clipboard holds blocks, block entities, and entities. It persists until you copy or cut again. The Clipboard window shows what is stored and exposes paste options.

ActionKeybindNotes
CopyCtrl+CCopies blocks and entities from the selection
Copy With Air(unbound)Includes air blocks in the copy; they will overwrite on paste
CutCtrl+XCopies then deletes the selection
PasteCtrl+VShows placement gizmo; click to confirm position
Paste and Select(unbound)Pastes and simultaneously selects the pasted region
DuplicateCtrl+JCopies the selection and immediately starts a paste

Paste Options

Paste Air
When on, air blocks in the clipboard overwrite existing world blocks. When off, only non-air blocks are written.
Keep Existing
Never overwrite non-air world blocks; only fill empty space.
Rotate / Scale
Before confirming, rotate the clipboard or scale it. Non-90-degree rotations and non-integer scales are flagged as lossy.

Rotation Algorithms

AlgorithmQualityBest For
Nearest NeighborFast90-degree rotations, large structures
RotSpriteHighArbitrary-angle rotations with less aliasing
Scale2xHigh2x integer upscale with edge enhancement
Scale3xHigh3x integer upscale with edge enhancement

Blueprint Workflow

flowchart LR
  A([Select Region]) --> B["Copy\nCtrl+C"]
  B --> C["Save Blueprint\nCtrl+P"]
  C --> D[("Blueprint File\n.blueprint")]
  D --> E[Blueprint Browser]
  E --> F{Use As}
  F -->|Paste once| G["Ctrl+V to paste"]
  F -->|Scatter| H[Stamp Tool]
  F -->|Share| I[Upload to Server]
        
drag to pan · scroll to zoom
Fig 3. Blueprint save and reuse workflow.

Blueprint Browser Features

Schematics

Import and export standard .schem schematic files via File → Import Schematic and File → Export Schematic. After import the structure lands in the clipboard ready to paste.


Tool Masks

Tool Masks restrict which blocks any tool is allowed to read from or write to. They are global — every tool respects the active mask. Open the mask editor from the Tool Masks window or menu.

Application Mode

Source Only
The mask tests the block the tool is targeting (reading)
Destination Only
The mask tests the block the tool will write to
Source and Destination
Both must pass the mask for the action to proceed

Mask Node Reference

NodeWhat It Matches
BlockA specific block or list of blocks
BiomeBlocks that fall within a specific biome
SurfaceBlocks that have at least one adjacent air block (surface-exposed)
Can See SkyBlocks with an unobstructed vertical path to the sky
In SelectionBlocks that are inside the current selection
Above / BelowBlocks above or below a Y coordinate
Adjacent / NeighborBlocks that are next to a block matching a sub-condition
NearBlocks within a specified radius of a position
AngleBlock faces at a specified surface angle (90 = up, 0 = horizontal, -90 = down) with a configurable tolerance range
OFFSETShifts which block is tested by the sub-mask by a position offset
NOTInverts the result of a sub-mask
ANDAll connected sub-masks must match
ORAt least one connected sub-mask must match
Example mask: paint only on upward-facing stone surfaces
AND Block: [stone, stone_bricks, cobblestone, mossy_cobblestone] Surface -- has at least one adjacent air face Angle: 60 to 90 degrees -- near-vertical upward-facing faces only
Example mask: paint only on blocks adjacent to water
Adjacent Block: [water] -- the adjacent neighbour must be water

Keybindings

All keybinds are fully rebindable in the Keybinds window. Two preset profiles: Axiom Defaults and Blender-like. Click a column header to sort.

Action ↕ Category ↕ Default
UndoEditCtrl+Z
RedoEditCtrl+Y
CopyEditCtrl+C
CutEditCtrl+X
PasteEditCtrl+V
DuplicateEditCtrl+J
DeleteEditDel
Save BlueprintEditCtrl+P
Extrude PointEditE
Confirm placementEditEnter
Quick FillOperationsCtrl+F
Quick ReplaceOperationsCtrl+R
Rotate PlacementOperationsCtrl+R
Flip PlacementOperationsCtrl+F
Rotate CameraCameraRMB
Arcball CameraCameraAlt+RMB
Pan CameraCameraAlt+LMB
Crosshair CameraCameraMMB
Use ToolCameraLMB
Adjust Tool RadiusCameraCtrl+Scroll
Move ForwardMovementW
Move LeftMovementA
Move BackwardMovementS
Move RightMovementD
Move UpMovementSpace
Move DownMovementLeft Shift
SprintMovementLeft Ctrl
Nudge ForwardsGizmoUp Arrow
Nudge BackwardsGizmoDown Arrow
Nudge RightGizmoRight Arrow
Nudge LeftGizmoLeft Arrow
Nudge +YGizmoPage Up
Nudge -YGizmoPage Down
Toggle Editor UICapability(set by user)
Toggle Angel PlacementCapability(set by user)
Toggle BulldozerCapability(set by user)
Toggle Fast PlaceCapability(set by user)
Toggle Force PlaceCapability(set by user)
Toggle No ClipCapability(set by user)
Toggle No UpdatesCapability(set by user)
Toggle Replace ModeCapability(set by user)
Toggle Infinite ReachCapability(set by user)
Toggle TinkerCapability(set by user)
Show BiomesViewCtrl+B
Switch Viewport 1-9ViewCtrl+1 to Ctrl+9
Context MenuIngameAlt
Jump to BlockIngame(set by user)
Orbit CameraIngame(set by user)
Swap to Last ToolTools(set by user)

World Properties

The World Properties window controls game rules without leaving the editor. Changes take effect immediately.

Blocks
Block Drops, Block Gravity, Fire Tick, Trample Farmland, Random Tick Speed
Time
Presets: Day / Noon / Night / Midnight; Freeze Time toggle
Weather
Clear / Rain / Thunder; Pause Weather toggle
Player
Invulnerability toggle
Mobs
Mob Spawning toggle

Additional Features

Reference Image
Open an image file as a floating in-game overlay. Adjust opacity, toggle linear/nearest filtering, go borderless. Useful for tracing pixel art or reference builds.
History Window
Every action is named ("Painted 100 blocks", "Moved 55 blocks", "Filled 30 blocks"). Left-click any entry to rewind; right-click to preview without committing.
Display Entity Editor
Create and edit Item Display, Block Display, and Text Display entities with full property control: billboard mode, glow colour, brightness, shadow, opacity, culling, interpolation.
Brush Studio
Save and manage reusable brush presets. Any combination of tool type and options can be saved as a named preset.
Color Picker
A Creative menu tab with RGB/HSV/Hex input for finding blocks by colour. Filters: Full Cube, Solid, Opaque, Same Texture.
Gradient Helper
A Creative menu tab for building multi-step block colour gradients. Define stops and get a palette of blocks ordered by brightness/hue.

Axiom 5.4.1 • Fabric mod • Minecraft 1.21+ • by Moulberry