stl-cube-scaffold

name: stl-cube-scaffold description: Analyze an STL mesh (AABB + approximate OBB) and generate a single connected STL that includes an L×L×L cube scaffold (default 100mm) plus connectors, so the final solid's OBB is locked to the target cube size for packing/measurement checks.

STL Cube Scaffold (AABB/OBB, default 100mm)

Goals

Compute an STL's AABB and an approximate OBB (random rotation sampling search)
Generate a single-piece STL: original model + L×L×L cube frame/pillars + connectors (default L=100mm)

Prerequisites

Python 3.8+ with: numpy, scipy, manifold3d

Workflow

1) Analyze the input STL (optional)

python scripts/stl_cube_support.py <in.stl> --analyze
python scripts/stl_cube_support.py <in.stl> --analyze --target <edge_mm>

If the script reports that the model cannot fit into the target cube (given the current search result), stop and confirm next steps with the user (e.g. increase <edge_mm>, or increase --samples/--search-points and retry the search).

2) Export a cube-scaffolded STL (recommended: `frame`, default L=100mm)

python scripts/stl_cube_support.py <in.stl> \
  --export-stl <out.stl> \
  --scaffold frame \
  --target <edge_mm>

If you omit --target, it defaults to 100 (mm).
Check the output:
- AABB dim: <edge_mm> x <edge_mm> x <edge_mm> mm
- Connected components: 1

3) Tuning options

Option	When to use
`--connector-penetration`, `--connector-count`, `--connector-thickness`	Multiple shells (`Connected components > 1`)
`--samples`, `--search-points`	Search didn't find a good orientation (can't fit into cube)
`--objective max`	Alternative optimization objective
`--scaffold frame`	Lock OBB to cube size (default, recommended)

How It Works

AABB vs OBB: An AABB (axis-aligned bounding box) depends on the model's orientation. An OBB (oriented bounding box, minimum-volume sense) is invariant under global rotation/translation.
Why add an L×L×L cube frame/pillars: By unioning an explicit L×L×L frame with the model, the final solid's minimum-volume OBB is forced to L×L×L.
Why connectors must intersect the model: If the scaffold is disconnected from the original mesh, slicers and mesh tools will treat it as multiple shells/parts. Connectors must have a volumetric intersection (not just touching) with the model to ensure the boolean union becomes a single connected solid.