Python script to load STL, OBJ, STP and FORM files & compute best packing arrangement

Developers
1

I have written a python script that uses Preform Server local API to load .form, .obj, .stl and .stp files, pack them and display statistics. If models need repair it can optionally call a Python mesh repair library. Finally it can calculate the cost of materials like Preform does. I’ll be creating a public github repro for it soon. Anyone have any feature requests?

usage: sls_packing_analyzer.py [-h] [--server-path SERVER_PATH] [--port PORT] [--machine MACHINE] [--material MATERIAL] [--spacing SPACING] [--list-materials]
                               [--auto-repair] [--cost-per-kg COST_PER_KG]
                               [files ...]

Analyze SLS packing efficiency for Formlabs Fuse printers

positional arguments:
  files                 One or more 3D model files (.form, .stl, .obj, .step, .stp)

optional arguments:
  -h, --help            show this help message and exit
  --server-path SERVER_PATH
                        Path to PreFormServer installation (auto-detected if not specified)
  --port PORT           Port for PreFormServer (default: 44388)
  --machine MACHINE     Machine type (e.g., FUSE-1-0, FUSE-1+-30W-0). Use --list-materials to see all options.
  --material MATERIAL   Material code (e.g., FLNYL2PA for Nylon 12). Use --list-materials to see all options.
  --spacing SPACING     Model spacing in mm (default: 5.0)
  --list-materials      List available machine types and materials, then exit
  --auto-repair         Attempt to repair models automatically if import fails (experimental)
  --cost-per-kg COST_PER_KG
                        Cost of powder per kg in USD (default: 120.0)

Examples:
  sls_packing_analyzer.py part1.form part2.form part3.form
  sls_packing_analyzer.py part1.stl part2.stl part3.obj
  sls_packing_analyzer.py model.step --machine FUSE-1+ --material FLNYL2PA
  sls_packing_analyzer.py *.stl --server-path /path/to/PreFormServer
  sls_packing_analyzer.py part1.stl part2.obj --spacing 3.0
  sls_packing_analyzer.py broken.stl --auto-repair

Supported file formats:
  .form - Formlabs PreForm scene files
  .stl  - STereoLithography files
  .obj  - Wavefront OBJ files
  .step - STEP 3D CAD files
  .stp  - STEP files (alternative extension)

Note: For best results with combinations, use STL/OBJ/STEP files.
Multiple .form files in combinations will only use the first file as base.
4 Likes
2

This is awesome. Thanks for sharing.

3

Hey man! This sounds incredible — I’d love to get my hands on it. That functionality would be a total game-changer!

Do you think it could be expanded to handle more than one plate at a time? I’m imagining a scenario where I load in 100+ parts queued for production, and it automatically organizes them into the most efficient set of build chambers to hit the highest packing density and minimize total print runs.

Any chance you could share what you’ve got so far? I’d be happy to test it out and give feedback. You can reach me at jeremiah.ison@merit3D.com or 4352993216