SynthBlocks

SynthBlocks is a visual programming system for creating custom toolpaths and printer behaviour. Instead of editing a profile curve, you snap together logical blocks that describe what to print, how to move, and how to extrude — and the engine compiles it into G-code.

What can you build?

Arbitrary 2D shapes lifted into 3D (spirals, stacked layers)
Procedural variation over height using math and variables
Speed, flow, and temperature changes at any point in the path
Repeating patterns with loops and seeded randomness
Anything that goes beyond the limits of a single profile curve

How it works

SynthBlocks uses a blocks-to-G-code pipeline:

Author — drag blocks onto the canvas and snap them together
Compile — the app translates your blocks into a typed data structure (Path Program IR)
Generate — the engine interprets the IR, samples geometry into toolpath points, and writes G-code
Preview — the 3D viewport shows the result in real time

This pipeline is deterministic: the same blocks with the same seed always produce the same output.

The interface

When you activate SynthBlocks, the workspace has three areas:

Area	What it does
Block canvas (left)	Drag blocks from the toolbox, snap them together to build your program. Scroll to zoom; click + drag on empty space to pan. No scrollbars — endless canvas.
3D viewport (center)	Live preview of the generated toolpath — same viewer as Profile mode
G-code inspector (bottom)	View generated G-code, warnings, and print statistics

Your printer, nozzle, and material settings apply automatically — no reconfiguration needed.

The toolbox

Blocks are organized into ten categories in the toolbox sidebar. Each category has a distinct color:

Category	Purpose
Structure	Toolpath root, path groups, sequences, loops
Geometry	2D shapes — circles, polylines, curves
Z Strategy	Lift 2D geometry into 3D — spiral, stacked layers
Transforms	Move, rotate, scale nested geometry
Process	Control speed, flow, temperature, and G-code commands
Travel	Travel moves, retraction, and unretraction
Variables	Create and update named variables for use in loops
Math	Numbers, context variables, expressions, randomness
Safety	Bounds checking, sampling, and debug markers
Printer Settings	Read-only printer and build volume values

Your first program

Every SynthBlocks design starts with a Toolpath block (created automatically). Inside it, you build your toolpath.

A simple spiral vase uses just three blocks:

Example: Spiral Vase

Interactive preview is available in the interactive reader.

The Toolpath block is already on the canvas with an empty Path Group
From Z Strategy, drag a Spiral Up block into the Path Group
From Geometry, drag a Circle block into the Spiral Up's geometry slot
The viewport updates with a spiral cylinder

Add variation by dragging a Variable (normZ) and Map Range block into the Circle's radius input — the cylinder becomes a tapered vase.

Key concepts

Path Groups

A Path Group is an independent toolpath. The engine processes groups sequentially and inserts travel moves (with zhop and retraction) between them. Use multiple groups when you want separate, non-connected paths.

Scoping

Blocks that wrap other blocks (Translate, Rotate, Scale, Spiral Up) create a scope. Their effect only applies to the blocks nested inside them — they never affect blocks outside.

Seed and randomness

The Toolpath block has a seed field (shown only when you use a Random block). All Random blocks use this seed to produce deterministic output. Change the seed to get a different variation; keep it fixed for reproducible results.

Context variables

Math blocks can read context variables that the engine updates automatically during generation:

Variable	Range	Meaning
`z`	mm	Current Z height
`normZ`	0–1	Normalized height (0 = bottom, 1 = top)
`layerIndex`	0, 1, 2...	Current layer number
`t`	0–1	Position along current segment
`s`	mm	Absolute path length so far
`normS`	0–1	Normalized path length

Use these with Map Range, Sin, or Clamp to create geometry and process values that change over height, position, or layer.

Named variables

The Variables category lets you create your own named variables. Click Create Variable, give it a name, and the toolbox automatically populates with ready-to-use Set and Get blocks for that variable. Unlike context variables, you control when and how named variables change — they are especially useful for accumulating values inside loops.

Variables with numeric initial values also appear as interactive controls in the 3D viewport, so you can drag to adjust values and see the result in real time without editing blocks. See the Variables documentation for details and examples.

Saving and presets

SynthBlocks designs are saved in .3dsynth project files, just like Profile designs. You can also save them as Design Presets to reuse or share. The block workspace is stored as part of the design module — no separate file format.