Script Brush

The Script Brush is a very unique tool, the scripting functionality mixed with useful functions can lead to near-unlimited possibilities. The use of clever logic can lead to things like simple texture generators all the way to structural generators.

Although intimidating at first, once you understand the basic concept of programming and have read this documentation, you'll be ready to make your own scripts!

Key Points

  • The Script Brush is a powerful, yet advanced tool so some knowledge of programming languages similar to Python is recommended.

  • The Script Brush is similar to Mask Scripting.

  • An IDE1 window is used to input your code. It uses a similar language to Python called Lua2.

  • Lua doesn't require line indentation like most languages but Axiom provides a tabbing feature to indent.

  • There is only one built-in library3 and there are currently no others.

The Script must use return blocks.stone or use setBlock(x,y,z,blocks.stone) to modify blocks in the world.

There are many predefined variables and functions that can be used throughout the script to interact with the world. Listed below, are all variables and functions with descriptions and examples.

Custom Variables

x,y,zThese three variables represent the XYZ coordinates.if y==5
blocksCan be used to retrieve the Blockstate ID for a block.blocks.stone

Custom Functions

getBlock(x,y,z)Returns the Blockstate ID at the given position (x,y,z).getBlock(x,y,z)==blocks.stone
getBlockState(x,y,z)Returns the Blockstate ID property at a given position.getBlockstate(x,y,z)==withBlockProperty(blocks.chain,"axis=x")
getHighestBlockYAt(x,z)Returns the Y value of the highest solid block on the X and Z coordinates.getHighestBlockYAt(x,z)==20
getSimplexNoise(x,y,z,seed)Returns a value between 0 and 1, representing the Simplex noise for the provided coordinates.getSimplexNoise(x,y,z,42)=>0.5
getVoroniEdgeNoise(x,y,z,seed)Returns a value between 0 and 1, representing the Voroni Edge noise for the provided coordinates.getVoroniEdgeNoise(x,y,z,01134)=>0.5
isSolid(Blockstate ID)Returns true if the Blockstate ID is solid, false if not.isSolid(getBlock(x,y,z))
isBlockTagged(Blockstate ID,"tag")Returns true if the Blockstate ID has the provided tag, false if not.isBlockTagged(getBlock(x,y,z),"wooden_fences")
withBlockProperty(Blockstate ID,"property=value")Used to return or set a Blockstate ID with a Blockstate ID property.withBlockProperty(blocks.oak_slab,"waterlogged=true")
getBlockProperty(Blockstate ID,"property")Returns the value of the provided Blockstate ID property.getBlockProperty(blocks.oak_slab,"waterlogged")==true
setBlock(x,y,z,Blockstate ID)Set an additional Blockstate ID at a given position.setBlock(x,y,z,blocks.stone)

Blockstate IDs with and without properties can be used in all functions which use a Blockstate ID

Template Variables

Template Variables are not shown in the help text. Template Variables are used to visually display tool settings, removing the need to edit values within the script itself. Most Template Variables Use a title, this is used to display the usage or function of the specific Template Variable. The default value is used to set the most appropriate value within the range. The min and max variables are used to set the ranges on sliders.

Template VariableDescriptionExample
$once$Runs the script once per click.$once$
$blockState(title,block)$Allows blocks to be input using GUI.$blockState(Block to Paint,stone)$
$int(title,default,min,max)$Creates a slider with whole values.$int(Randomness Multiplier,1,0,2)$
$float(title,default,min,max)$Creates a slider with decimal values.$float(Noise Threshold,0.5,0,1)$
$boolean(title,default(true/false))$Creates a toggle$boolean(Disable Randomness,true)$

Code Examples

These four code examples range from a novice user all the way to a professional in terms of difficulty. Each script provides a description and a breakdown of how the script works. Feel free to copy these and mess around with them.


This script below is very basic, it replaces oak leaves with birch leaves.

if getBlock(x,y,z)==blocks.oak_leaves then
	return blocks.birch_leaves
Novice Code Breakdown
The if check ensures that the current block is oak leaves. Using "getBlock(x,y,z)" targets the active block. 

Then "blocks.oak_leaves" is used to check if the block IDs match.

Finally, the script returns birch leaves, therefore replacing oak leaves.


This script places pink petal flowers using simplex noise to control the block property.


if getBlock(x,y,z)==blocks.air and isSolid(getBlock(x,y-1,z)) and noise<(0.75*multiplier) then
    return withBlockProperty(blocks.pink_petals,"flower_amount="..math.floor((getSimplexNoise(x/2,y/2,z/2,0)*4)))
Advanced Code Breakdown
Firstly, The multiplier and noise variables by utilising the float variable and the simplex noise function.

Then the script checks that the block is air and is above a solid surface while also checking if the noise is within range.

Finally, the block is placed using "withBlockProperty" to set the flower amount property. This uses a modified simplex noise that returns values between 0 and 4.


The script below generates kelp in water using a maximum height to control the length of kelp.

heightMax=$int(Maximum Height,25,1,50)$


if noise<(multiplier*0.1) and isSolid(getBlock(x,y-length,z)) and getBlock(x,y,z)==blocks.water then
    for block = 0,length do
        if not isSolid(getBlock(x,y-block,z)) then
    return blocks.kelp
Expert Code Breakdown
Firstly, the script defines all the variables. 

As the script builds the kelp from top to bottom, it checks if the lowest attemptable block is solid.  

Then, for each solid block, the script places a kelp plant.

Once all kelp plant blocks are placed, the script then sets the active block to be the top piece of kelp. 


This final script creates a curved bowl shape using mathematical formulae. This is one of the most complex types of script brushes in Axiom.

scale = $int(Scale,30,10,50)$
flatness = $float(Bowl Flatness,0.8,0.1,2.5)$
tolerance = (scale*10)*flatness

function isTolerable(a, b, tol)
    return math.abs(a - b) <= tol

for DistX = -scale, scale do
    for DistY = -scale, scale do
        for DistZ = -scale, scale do
            local formulaL = DistX^2 + DistY^2 + (DistZ^1.5)*-(flatness*10)^2
            local formulaR = 0
            if isTolerable(formulaL, formulaR, tolerance) then
                setBlock(x + DistX, y + DistZ, z + DistY, block)
Professional Code Breakdown
This script represents the following equation:
Where n is the flatness variable. 

The script draws the 3D shape by using a loop for each axis.



An integrated development environment (IDE) is a software application that provides comprehensive facilities for software development.


Lua is a lightweight programming language designed for embedded use within applications.


The Math Library is the only built-in library in the Script Brush.