Wraps torwanbukaj/ikea-brio-others-compatible-train-tracks-generator
( https://github.com/torwanbukaj/... ) as a third generator alongside
holder and the universal scad playground.
Approach
--------
The upstream .scad ships as "library + one active example call". Used
include<> (rather than use<>) so the library's top-level globals
(track_width, plug/nest dimensions, $fn = 150, etc.) are available
to the modules — `use<>` does NOT propagate variables. Commented out
the upstream `track_tester();` call so include<> doesn't also emit
the tester geometry every time.
Per-render the backend builds a tiny wrapper SCAD on the fly:
include <scad/train_tracks.scad>
track(length=100, end1="plug", end2="nest", cutout=true, ...);
and hands it to holder.render_source().
Part types exposed (9)
----------------------
- tester Calibration block (15-60mm)
- track Straight (length + chamfers + grooves + plug/nest ends)
- arc Curved (radius + angle, IKEA/Brio/J'adore radii in help text)
- dogbone Nest-nest connector
- intersection Crossing (angle + 2 lengths + 4 ends)
- switch Turnout (left/right radius+angle, straight branch, common end)
- snake S-curve (raised default target_length to 200 — the upstream
modules's natural curvy-span at angle=45/radius=86 is ~150
and the assert fires below that)
- adapter BRIO <-> IKEA system adapter (plug + nest side)
- bridge Multi-part (overview/ground/slope/pillar — value_map
translates the UI labels to the int 0..3 the SCAD wants)
Files
-----
- scad/train_tracks.scad Downloaded upstream (57 999 bytes), only
modification is the // before the top-level
track_tester() call.
- tracks.py PART_SCHEMAS dict, build_wrapper_scad,
render() that delegates to render_source.
- app.py GET /api/tracks/params, POST /api/tracks/render,
GET /tracks page route.
- static/tracks.html Page with part selector + dynamic param form +
shared viewer markup. Reuses holder.css.
- static/js/tracks-app.js Controller. Switching the part select redraws
the form (each part has its own schema).
Ctrl+Enter renders, Cancel uses AbortController.
Nav
---
Tracks link added to topbar on holder / index / scad.
Smoke test
----------
All 9 parts render with default params on the Manifold backend in
under 0.5s each (output sizes 440 KB - 1.8 MB).
The bundled hex_cell.scad has many more knobs than the dozen we used to
expose (box clearances, cap/box wall, vertical stacking, busbar template,
etc). Maintaining a hand-curated PARAMS list in Python next to a SCAD file
that already documents every variable inline was always going to drift.
Sync + auto-extract approach:
- scad/hex_cell.scad: replace with the upstream master file from
Albert Phan's Hex-Cell-Holder fork (adds the BUSBAR TEMPLATE section
and the "busbar template" part option).
- holder.py: PARAMS now built at import time by _scan_scad(), which
regexes top-level `name = literal; // help` lines into Param entries
up until the // END OF CONFIGURATION marker. Scan handles bool /
number / string literals; derived expressions and helper variables
are skipped automatically.
- Manual maps stay small and explicit: _SELECT_OPTIONS for the few
string-enum params (part, pack_style, box_style, template_outline,
template_hole_style, etc.), _GROUP_RULES for UI sectioning, and
_NUMBER_HINTS for sensible min/max/step on the most-tweaked numbers.
UI:
- holder-app.js: extra GROUP_ORDER / GROUP_LABELS for the new
sections (cap, box, insulator, bolts, wires, stacking, template,
advanced). Group titles are now click-to-collapse; the advanced
groups start collapsed so the form isn't a wall of inputs on load.
- holder.css: caret marker on the group title, smooth rotate on
collapse, hides the body via .collapsed class.
Net effect: every variable in the .scad — including the new busbar
template knobs — is editable from the page, with helpful comments
copied straight from the .scad source.
Server-side OpenSCAD renders STL from bundled hex_cell.scad with parameter
overrides via -D. Frontend is a Three.js viewer with auto-form generated
from /api/holder/params. 'Design busbars →' button posts the computed
cell coordinates to /api/projects and redirects to the busbar editor with
the holder cells pre-loaded.
- holder.py: openscad subprocess wrapper + compute_cells()
(Python mirror of get_hex_center_points_*)
- scad/hex_cell.scad: verbatim copy of Addy/Hex-Cell-Holder source
- app.py: /holder route + /api/holder/{params,render,cells}
- static/holder.html etc: parameter form + Three.js STL viewer
- Dockerfile / install.sh: apt install openscad
- static/index.html: nav link Holder ↔ Busbars in topbar
wenil