About Lua in Netfabb

Introduction

Lua is Netfabb's method of choice to facilitate automation tasks inside the software, available in Netfabb Ultimate and Netfabb Premium. One particular advantage is that a Lua script may work on entirely different parts and project than currently loaded in Netfabb, if any.

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Supported Lua scope

Netfabb employs version 5.1 of the Lua language definition, see: http://www.lua.org/manual/5.1/

Of the Lua 5.1 standard, Netfabb supports the core language specification as well as selected libraries.

Lua library	Support	Note
Base	Yes, with exceptions	Some exceptions: dofile: use system:executescriptfile() instead print: use system:log() instead. Remember to first set where the logging should go, with `system:logtofile("c:\lualog.txt");` for example; otherwise the only place to follow logging output is the debugger.
Coroutine manipulation	Yes
Modules	No	Use system:executescriptfile()
String manipulation	Yes
Table manipulation	Yes
Mathematical functions	Yes
Input and output facilities	No
Operating system facilities	No
Debug library	No	For Lua in the Netfabb default 3D view, also referred to as desktop automation, a debugger GUI is available.

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Lua API reference

The objects, properties, and methods available in Netfabb's Lua implementation are documented in their own section in the online help.

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API scopes

Netfabb's Lua capabilities are split into scopes. In the Netfabb Lua API reference (https://help.autodesk.com/view/NETF/2025/ENU/?guid=NETF-LUA-APIREF), the different scopes are indicated with these tags where necessary.

Scope	Purpose	API reference tag
Desktop automation, 3D parts, GUI	Automate steps in regular 3D workflow, optionally with custom GUI dialogs, optionally involving the current buildroom or any parts present within it	[Desktop Automation]
Slices	Automating the generation and modification of slice stacks similar to desktop automation but focused on work within the Slices project tree section	[Slices]
Selective Space Structures	Algorithmic control of application of lattice structures to 3D geometry	[3S]

Important: Scopes cannot be crossed over. Although objects and their methods and functions may appear in more than one scope, they are independent and cannot interact. For example, while Lua automation can load and slice a 3D model and export the results, it is not possible to also add the slice stacks so generated to the Slicing project tree section in the same script. The Slices section must be selected and any slice stacks then loaded manually.

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Lua script library

Desktop automation only: To make Lua scripts available for execution within Netfabb they are stored in a library, that means creating and editing, or loading them from files, and then storing them internally. The library resides in Netfabb's settings database. The library provides several functions:

If running Lua scripts happens often during working with Netfabb, set any script in the library to appear in a dropdown menu in the toolbar.
The icon in the toolbar makes Lua scripts readily available.
The library provides a Debugger to have a closer look at the operation of a script. You can run one line at a time, observe variables, set breakpoints to halt execution at specified steps, and observe output written for logging purposes.
Stepping through a script can help with identifying mistakes
If Netfabb's settings database is made available on a network, the scripts become available for all connected Netfabb installations.

Lua scripts for slicing and 3S do not make use of a library. For slicing, they are always loaded from files, authored externally. For 3S, they are authored individually per project in a dedicated editor GUI in Netfabb.

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Script examples

Netfabb includes a number of example scripts that demonstrate how to address a variety of tasks with Lua. These can be found in the library as well as at Examples\LUA Scripts in the Netfabb installation directory. Some of them may require modification to meet your particular installation and paths.

Noteworthy examples are the scripts DemoApplication and DemoWorkflows. Both are full applications written in Lua and run within Netfabb. They implement a selection from the example scripts and make them available via GUI to demonstrate not only the use of such scripts but also how to implement a GUI to collate such functions. They are two of the default scripts loaded in the library.

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