Writing Functions¶

A reusable function is a DSL script whose inputs become function parameters and whose outputs become its returned values. Save the script to Local to use it from other scripts.

Write the Function¶

Create the function in a Blender Text datablock. Use input_* methods for parameters and output(...) for the result.

geometry = input_geometry('Geometry')
translation = input_vector('Translation', default=vector(0, 0, 1))

result = transform(geometry, translation=translation)
output('Geometry', result)

The input socket names define the parameters exposed by the function. Call arguments can be positional or use unique input labels as keywords.

Each input_*() call creates a separate parameter. If two inputs have the same displayed label, call the function positionally because that label is ambiguous as a keyword.

Return Multiple Values¶

Declare more than one output when the caller needs separate values.

geometry = input_geometry('Geometry')
value = input_float('Value', default=1.0)

result = transform(geometry, scale=value)
output('Geometry', result)
output('Scaled Value', value * 2.0)

Unpack the results in the same order as the output declarations.

from local import scale_and_measure

geometry = input_geometry('Geometry')
result, scaled_value = scale_and_measure(geometry, 2.0)
output('Geometry', result)
output('Scaled Value', scaled_value)

You can also store the fixed result and select an output with a compile-time integer index, including a negative index.

Save to Local¶

Open Library → Local, browse to a NodeForge-managed folder, then click Save.

Enter a name for the selected Text datablock. The saved name becomes the function name used by imports. Use letters, digits, and underscores, and begin the name with a letter. Enable Overwrite when replacing an existing function.

You can also use Add Folder... to register an existing directory of .nf files. External Local folders are read-only in NodeForge; edit those files with your normal editor.

Use the Function¶

Import the saved script from local and call it with the inputs declared by the function.

from local import move_geometry

geometry = input_geometry('Geometry')
result = move_geometry(geometry, translation=vector(0, 0, 2))
output('Geometry', result)

See Imports for aliases, star imports, and name-resolution rules.

Update the Function¶

For a managed Local function, load or open its source in a Text datablock, edit it, then save it to the same Local path with Overwrite enabled. For an external Local function, edit its .nf file on disk.

Existing generated groups keep the dependency source used when they were compiled. Compile a new caller to use the current function source, or select an existing library-backed group node and click Reload from Source to rebuild that group in place. Compatible links and input values are preserved during the reload.