CAD add-in · Preview
Pick a polyline, choose an aircraft, and the swept envelope, clearance envelope, gear and wingtip tracks, footprints and issues are drawn on dedicated TX-* layers — ready for your sheets, xrefs and plot styles.
tractrix-engine, or Tractrix CloudCommands
Each command maps to a task of the tractrix/1 protocol, so a DWG study and a QGIS study of the same layout give the same numbers.
| Command | What it does | Engine task | Status |
|---|---|---|---|
| TXPATH | Aircraft taxi or group path along a selected polyline, with nose-gear, cockpit or custom tracking | aircraft_path | Preview |
| TXPUSHBACK | Pushback or forward tow with a towbar or towbarless tug | pushback | Preview |
| TXTURN | Turning radii R1–R6 table and the 180° turn drawn at a picked point | turning | Preview |
| TXJETBLAST | Jet blast contours and intake hazard areas at picked positions | jet_blast | Preview |
| TXGSE | Ground vehicle and trailer-train swept path with jack-knife check | vehicle_path | Preview |
| TXLIBRARY | Browse the aircraft and vehicle libraries | library | Preview |
| TXSETTINGS | Local or cloud engine, API token, default standard, drawing options | — | Preview |
| TXRESULTS | Results palette: pass/fail summary of the latest run | — | Preview |
| TXCLEAR | Erase one or all Tractrix results from the drawing | — | Preview |
| TXREPORT | Write a report of the last results | — | Preview |
| TXRERUN | Run a stored result again with its saved request | (stored task) | Preview |
| Stand, fillet | Stand design and taxiway fillets | stand, fillet | Planned v1.1 |
Layers
Tractrix never edits your own geometry. Everything it draws goes on layers whose names start with TX-, with true colours from the Tractrix palette, the nearest ACI colour for exports that drop true colour, and lineweights and transparency chosen to plot well.
Freeze, lock, rename in a layer translator, or remove them in one go with TXCLEAR.
| Layer | Contents |
|---|---|
| TX-ENVELOPE | Swept envelope (filled) |
| TX-CLEARANCE | Clearance envelope (dashed) |
| TX-SWATH-MAINGEAR | Main-gear swath |
| TX-TRACK-MAINGEAR | Outer main-gear tyre tracks |
| TX-TRACK-WINGTIP | Wingtip tracks |
| TX-FOOTPRINT | Aircraft outline along the path |
| TX-ISSUE | Steering, edge-margin and conflict issues |
| TX-JETBLAST-56 | Jet blast contour, 56 km/h (one layer per velocity) |
Engine
The add-in is a thin client. It sends a tractrix/1 request and draws the response; the mathematics lives in one place.
Local engine
The add-in starts tractrix-engine run and exchanges JSON over standard input and output. Nothing leaves the workstation. It finds the engine through the path in TXSETTINGS, the TRACTRIX_ENGINE environment variable, the installation folders, or PATH.
Cloud engine
Paste a Tractrix Cloud API token into TXSETTINGS and requests go to POST /api/v1/simulate over HTTPS. The token is stored encrypted for your Windows user, never in the drawing.
The add-in is open source. Follow the repository to be notified, or build it yourself from cad/.