LDraw for PartCAD

Exposes the LDraw parts library as PartCAD parts, published as //pub/universe/lego/ldraw. Every LDraw category becomes a sub-package, and every part in it is a parametric :ldraw part that meshes the LDraw .dat on demand.

Nothing is vendored: the category list, the per-category part lists (paginated in full), the part metadata and the part geometry are all fetched from ldraw.org and cached on disk on first use.

How it works

Two mechanisms are combined:

1. An external repository plugin (ldraw_repo.py). It serves the package contents over PartCAD's key/value repository protocol:

   • the categories (from parts/category-list) as top-level sub-packages;
   • within each category, the complete list of parts (walking every page of parts/list), each with its description, author and license read from the part's .dat header. Category enumeration is lazy (per category) and every remote call — each list page and each .dat — is cached under ~/.cache/partcad-ldraw/, consistent with how partcad-bosl2 caches BOSL2.

2. A wrapper partType (ldraw.py). Each part's type is :ldraw, which resolves to this partType. The wrapper fetches the part's .dat, recursively resolves its sub-parts, meshes the triangles/quads, and returns the shape.

Layout

Path	Purpose
partcad.yaml	//pub/universe/lego; the ldraw external dependency (the library), the ldraw_repo repository, and the ldraw partType.
ldraw_repo.py	Repository plugin: categories, paginated part lists, .dat-header metadata, the partType, and the wrapper file.
ldraw.py	The :ldraw partType wrapper: fetch + recursively mesh a .dat.

Usage

# Categories (top-level sub-packages)
pc list packages //pub/universe/lego/ldraw

# The complete part list of a category (first use fetches + caches it)
pc list parts //pub/universe/lego/ldraw/Brick

# Render any LDraw part to an image
pc inspect //pub/universe/lego/ldraw/Brick:3001

Caching

Everything fetched from ldraw.org is cached under ~/.cache/partcad-ldraw/ (override with PARTCAD_LDRAW_CACHE):

category-list.html                 the category list
categories/<Category>/page-N.html  each part-list page
parts/<id>.dat                      each part (also used by the render)

Requirements

Requires a PartCAD version that provides plugin-backed (external) packages and partTypes (partcad: ">=0.7.146" in partcad.yaml). Because parts are fetched on demand, first use of a part or category needs network access; afterwards the cache is used.

Licensing

The code here is Apache-2.0 (LICENSE). LDraw parts are not bundled; they are fetched from ldraw.org and remain under their own per-part licenses (CC BY 4.0 / CCAL), recorded in each part's .dat header. See NOTICE.