Install

Requirements

Blender	5.0 or newer (tested on 5.0, 5.1, 5.2 LTS)
Platform	Windows / macOS / Linux for the add-on (pure Python); the packaged STEP converter is Windows-only for now
STEP import	needs a separate converter binary — see below
Plasticity bridge import	nothing extra

The add-on

Download from the latest release: one zip (hardcraft-<version>.zip), Blender 5.0+ — there is no per-Blender-version choice to make. A SHA-256 for every file is published in the release body.

Before testing, read Known issues — this is an alpha of a working tool, not a finished product.

1. In Blender: Edit → Preferences → Get Extensions → ⌄ → Install from Disk…
2. Pick the zip. The add-on registers as bl_ext.user_default.hardcraft.
3. A Hardcraft tab appears in the 3D viewport's N-panel.

Nothing else to configure — every numeric default lives in the add-on and is overridable later (see Settings).

The CAD converter (STEP only)

STEP import needs OpenCASCADE, which cannot be imported inside Blender's Python. So the conversion runs in a separate self-contained executable, hc-cadconv (a native OCCT build, ~35 MB, no external dependencies). The Plasticity bridge path does not use it at all.

An installer — nothing to place by hand

Hardcraft CAD Tools is a per-user installer from the same release (hardcraft-cadtools-<version>-win64.exe): no admin rights, lands in %LOCALAPPDATA%\hardcraft\bin\hc-cadconv, uninstalls from Apps & features. The add-on finds it by itself. It is unsigned — Windows 10 may show SmartScreen once (More info → Run anyway); verify the published SHA-256 instead. It does not use the network. Its version (1.1.0) is independent of the add-on's; a protocol handshake decides compatibility.

Windows only, for now

A packaged converter exists for Windows only. On macOS and Linux, install a Python with the OpenCASCADE bindings (pip install cadquery-ocp) and set the STEP_CONVERTER_PY key in Hardcraft's settings.json (<blender config>/hardcraft/settings.json — see Settings) to that python — same conversion, same output. (This is a dev-flavoured path on purpose and has no UI field; it goes away when those platforms get a package.) The Plasticity bridge and OBJ paths need none of this.

If you point Hardcraft at a converter yourself — a custom build, or a location your studio manages — set the CAD converter path in the add-on preferences (Edit → Preferences → Add-ons → Hardcraft), or the HC_CADCONV environment variable. Both override whatever shipped.

Check it before you need it

In Object Mode the Hardcraft panel prints which converter would run, or why none was found — and verifies it by itself: a freshly found binary shows a brief checking… while the add-on runs the protocol handshake, then settles:

binary: hc-cadconv.exe · checking…            →  found, verifying
binary: hc-cadconv.exe · protocol 2 · OCCT …  →  ready
CAD converter not found …                     →  nothing resolved

A stale or broken converter therefore fails with a readable message right in the panel, before any import — never by half-importing a mesh.