Enumerated from the source rather than from recollection: CadFeatureType and
add_* in CadDocument.hpp, Tool in DesignPanel.hpp, Mode in
DesignSketchTool.hpp, SketchConstraintType + SketchEntity::Type in
SketchEngine.hpp, and the JSON-RPC dispatch in McpControl.cpp.
Findings worth stating up front:
- The 2D sketcher is at or near Onshape parity -- 19 constraints, every entity
type including B-splines and elliptical arcs, trim/extend/offset/mirror and
both array kinds. Very little is missing there.
- The gaps are all breadth beyond sketching: assemblies/mates, surface
modelling, sheet metal, drawings, and variables/configurations.
- The most defensible criticism is the absence of variables and expressions.
Every dimension is a literal double, so the feature tree is parametric in
structure but not in value -- "change one number and the model updates" is
only half delivered. It is also the cheapest Tier 1 item to close.
The doc separates platform capabilities (version control, FeatureScript, FEA,
rendering, cloud PDM) into their own tier rather than counting them as missing
tools: that is Onshape-the-platform, not Onshape-the-modeller, and holding a
slicer tab to it would not be a fair comparison.
One entry is a correctness gap rather than a missing feature: move/rotate body
(m_body_xform) is display-only and never enters the B-rep, so a moved body
exports and booleans at its original position while the viewport shows it
moved.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BVzKmX6Y1aEteit1HTXG4Q
The 2026-06-21 assessment was written before the persistence work landed and
got two load-bearing facts wrong. Both are corrected here against the branch
itself rather than from recollection:
1. It called OCCT "a dependency mainline OrcaSlicer has never carried" and
built its whole conclusion on that. False: deps/OCCT/ exists at the
merge-base, and upstream already links it from Format/STEP.cpp,
Format/svg.cpp and Shape/TextShape.cpp. The real dependency diff is one
line -- BUILD_MODULE_ModelingAlgorithms OFF -> ON -- costing a measured
3.77 MiB of Windows DLLs (TKFillet + TKOffset; TKBool already arrives
transitively via DataExchange).
2. It described the vendored SolveSpace solver as LGPL. False:
src/libslic3r/slvs/LICENSE is GPL-3.0. Harmless for us, but a licence
must not be misstated in a document aimed at upstream.
It also claimed no changes to Model, which stopped being true when 3MF
recipe persistence added a std::string there.
The rewrite replaces prose estimates with counted figures: 138 new files,
23 modified upstream files at +457/-75, nothing deleted, 99.3 % of the diff
in new files. That reframes the ask from "adopt a CAD kernel" to "widen a
build flag you already carry", which is the argument that actually has a
chance upstream.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BVzKmX6Y1aEteit1HTXG4Q
