FreeCAD-Nxt (trial)

FreeCAD-Nxt is a FreeCAD add-on by Joe (obelisk79), in the style of Fusion and Onshape and built on Qt Quick. It adds a model panel with a rollback bar, a Property Inspector, drag-handle value boxes, its own fillet and chamfer, a section view with filled cut faces, Isolate and Quick Mass. NX-Style bundles it, unmodified, as a git submodule (vendor/FreeCAD-Nxt, version 0.5.15), and it is off by default. This is the first of several steps that bring parts of it into NX’s commands; for now it runs beside NX-Style as it is.

Nxt’s section view in NX-Style: the cut faces are hatched

Turning it on

python launch_nx.py --nxt starts with it once.
"nxt": true in the settings switches it on for good.

It needs FreeCAD 1.1 or newer; on FreeCAD 1.0 the launcher says so and starts without it. Its commands are under Menu › View › FreeCAD-Nxt, and its panel is the Model (Nxt) tab beside the Part Navigator. A copy of Nxt installed in the NX profile’s own Mod folder (through the Addon Manager) is used instead of the bundled one, so it never loads twice; FreeCAD loads that copy whether or not --nxt is given.

Nxt is not a workbench: it is a freecad.nxt package that adds its panel and commands to every workbench.

What NX-Style changes in it

Nothing in Nxt’s code. In the NX profile, NX-Style sets one of Nxt’s own preferences before Nxt starts: CheckAddonUpdates off. Nxt otherwise looks for updates of every installed add-on after start-up and offers the Addon Manager’s Update all dialog; NX-Style’s add-ons are pinned versions, updated with NX-Style itself.

What works on FreeCAD 1.1.4

Measured with the self-test (--smoke-test --nxt) on FreeCAD 1.1.4 (Qt 6.8.3), Windows 11.

Nxt feature FreeCAD 1.1.4 What was seen

Nxt feature	FreeCAD 1.1.4	What was seen
Model panel (tree, timeline)	works	Opens as the Model (Nxt) tab in the left tab strip; the Part Navigator stays in front.
Property Inspector	works	Opens beside the panel for the selected feature.
Isolate	works	Shows only the selection; leaving it shows everything again.
Section view, filled cut faces	works	The cut faces are hatched; the plane can be dragged, with an Offset box.
Quick Mass	works	The mass bar appears at the bottom of the graphics window.
Drag handles with value boxes	works	Editing a Pad shows FreeCAD’s two arrows and two taper handles, with Nxt’s Length and Taper boxes beside them.
Nxt fillet and chamfer	works	Opens its task panel and makes an `NxtFillet` feature that recomputes cleanly.
Rollback (the Body’s tip)	works	Nxt’s panel moves the tip back to the Sketch and forward to the Pad.
Menu entry	works	Menu › View › FreeCAD-Nxt lists Nxt’s commands.

Model panel (tree, timeline)

works

Opens as the Model (Nxt) tab in the left tab strip; the Part Navigator stays in front.

Property Inspector

works

Opens beside the panel for the selected feature.

Isolate

works

Shows only the selection; leaving it shows everything again.

Section view, filled cut faces

works

The cut faces are hatched; the plane can be dragged, with an Offset box.

Quick Mass

works

The mass bar appears at the bottom of the graphics window.

Drag handles with value boxes

works

Editing a Pad shows FreeCAD’s two arrows and two taper handles, with Nxt’s Length and Taper boxes beside them.

Nxt fillet and chamfer

works

Opens its task panel and makes an NxtFillet feature that recomputes cleanly.

Rollback (the Body’s tip)

works

Nxt’s panel moves the tip back to the Sketch and forward to the Pad.

Menu entry

works

Menu › View › FreeCAD-Nxt lists Nxt’s commands.

A Pad in edit with Nxt on: FreeCAD’s drag handles

Nxt’s drag handles are FreeCAD’s own ("gizmos"), which FreeCAD 1.1 already has; nothing above needed a FreeCAD 26.x build. Nxt’s author works on FreeCAD 26.3 (Qt 6.11); its context menu uses a Qt 6.8 feature, which FreeCAD 1.1.4 ships. Not exercised yet: drag reorder, dependency arrows, the detail strip, face snapping and the context menu, which need real mouse work in Nxt’s Qt Quick panel; they come with the next steps.

The tutorials with Nxt on

Nxt is not ready to be on by default: with it on, NX-Style’s own Extrude and Revolve dialogs lose what is typed into them. All 48 tutorial replays were run with Nxt off and on, each group of tutorials in a fresh FreeCAD 1.1.4.

	Steps run	FAILED	Steps not run after a failure
Nxt off	771	6	0
Nxt on	742	25	40

The six with Nxt off fail with Nxt on too, the same way, and have nothing to do with Nxt (three Ctrl+S save checks, an Orient View, and two steps of the Carbon tutorial that tutorial AN runs). The regressions with Nxt on:

Extrude and Revolve values are lost (tutorials AE, AF, AJ: an End of 20 or 60 mm gives FreeCAD’s default 10 mm; AO: Revolve takes none of the 10 picked curves). Nxt replaces FreeCAD’s Pad, Pocket and Revolve parameter boxes with its own cards; with that replacement removed, tutorial AE replays as with Nxt off, while switching off only Nxt’s floating value boxes does not help. Revolve’s box is replaced the same way; that AO fails for the same reason is likely but was not tested on its own. Nxt has no setting for the replacement yet.
Offset Curve in a sketch (tutorial I): the Add offset constraint option does not take, so the offset loop stays where the click put it (14.6 mm instead of 15). It repeats; the cause is not yet known.
Datum Plane, Datum Axis and Hole (tutorial AN): a typed offset reads 0, the datum axis stays unattached, and the Hole’s sketch does not start. The cause is not yet known.

The other tutorials (A to H, J to Z, AA to AD, AG, AH, AK, AP to AY) replay as with Nxt off.

Where it meets NX-Style

Measured with the self-test, Nxt on against Nxt off:

Where What happens with Nxt on

Where	What happens with Nxt on
`Space` in the graphics window	Nxt takes it: it hides or shows the feature behind the pick (a Pad, not its Body). FreeCAD’s own Space command (Show/Hide, `Std_ToggleVisibility`) no longer gets the key.
`Home`, `End` in Nxt’s panel	While Nxt’s panel has the keyboard focus, Nxt keeps them for its own list; they do not turn the view to Trimetric and Isometric. In the graphics window they keep their NX meaning.
`F2`	In the Part Navigator it still opens the name editor.
Toolbars	Nxt adds a toolbar of its own (Nxt Fillet/Chamfer) when Part Design starts. It shows above the ribbon, where NX-Style hides FreeCAD’s toolbars.
Model panel	Nxt tabs its panel beside FreeCAD’s Model dock, so the Part Navigator, Dialog and Versions strip gains a Model (Nxt) tab.
Colours	Nxt takes its colours from the window around it: background `#f0f0f0`, text `#1e2329`, but a grey accent (`#606060`) where NX-Style uses teal (`#0B6E79`).
Drag-handle preferences	On its first run Nxt sets two FreeCAD preferences that no FreeCAD page shows: a plain drag moves in fine steps and `Ctrl` gives coarse ones (FreeCAD: coarse first, `Shift` for fine). Nxt records what it replaced and puts it back when it is disabled or removed.
Sketch profiles	Nxt’s sketch repair is on, and changes the sketch without asking: a Pad on a rectangle with a 0.01 mm gap, which fails with Nxt off, is valid with Nxt on, because Nxt added a Coincident constraint. It offers Undo afterwards.
Task dialogs	Nxt replaces the parameter boxes of FreeCAD’s Pad, Pocket and Revolve dialogs, which NX-Style’s Extrude and Revolve drive (see the tutorials above).

Space in the graphics window

Nxt takes it: it hides or shows the feature behind the pick (a Pad, not its Body). FreeCAD’s own Space command (Show/Hide, Std_ToggleVisibility) no longer gets the key.

Home, End in Nxt’s panel

While Nxt’s panel has the keyboard focus, Nxt keeps them for its own list; they do not turn the view to Trimetric and Isometric. In the graphics window they keep their NX meaning.

F2

In the Part Navigator it still opens the name editor.

Toolbars

Nxt adds a toolbar of its own (Nxt Fillet/Chamfer) when Part Design starts. It shows above the ribbon, where NX-Style hides FreeCAD’s toolbars.

Model panel

Nxt tabs its panel beside FreeCAD’s Model dock, so the Part Navigator, Dialog and Versions strip gains a Model (Nxt) tab.

Colours

Nxt takes its colours from the window around it: background #f0f0f0, text #1e2329, but a grey accent (#606060) where NX-Style uses teal (#0B6E79).

Drag-handle preferences

On its first run Nxt sets two FreeCAD preferences that no FreeCAD page shows: a plain drag moves in fine steps and Ctrl gives coarse ones (FreeCAD: coarse first, Shift for fine). Nxt records what it replaced and puts it back when it is disabled or removed.

Sketch profiles

Nxt’s sketch repair is on, and changes the sketch without asking: a Pad on a rectangle with a 0.01 mm gap, which fails with Nxt off, is valid with Nxt on, because Nxt added a Coincident constraint. It offers Undo afterwards.

Task dialogs

Nxt replaces the parameter boxes of FreeCAD’s Pad, Pocket and Revolve dialogs, which NX-Style’s Extrude and Revolve drive (see the tutorials above).

Turning it off again

Leave out --nxt, or set "nxt": false (the default). Nxt’s own settings stay in the NX profile’s user.cfg under Mod/Nxt; they do nothing while Nxt is off.

Licence

FreeCAD-Nxt is LGPL-2.1-or-later, as NX-Style is, and included unmodified. Changes it needs go to its own repository.