LEparagliding Studio 0.3.5

LEparagliding Studio is a free, cross-platform design tool for paragliders — a modern Qt / Open CASCADE port of Pere Casellas' LEparagliding 3.28. Draw your wing with live curve editors, preview the exact 3D shape (NURBS/STEP, DXF, STL), analyse airfoils with the built-in XFLR5, and test the design in the Playground: a soft-body simulation that inflates your actual wing and measures how well it holds its designed shape under flight load.

What's new in 0.3.5

This release rebuilds the Playground from a toy into a wind-tunnel instrument — and, separately, teaches the wing to fly.

The wind tunnel

• Flight load — the tethered wing is loaded with a realistic ~1.5 kN wing-level resultant (imposed as pressure, anchored on the designed hang line), so line loads and shape response mean something. On by default; the load is prescribed by the Angle slider, and the angle the rigging actually holds is an output you read, not an input you fight.
• Live shape instruments — the wing is measured continuously against its design shape (the mesh samples the exact ballooning law, so the rest pose is the design): per-section deviation and washout change, leading-edge dent, slack fabric, span/area/volume retention, mirror asymmetry, and per-row line loads (A/B/C/D, left/right) read from the exact solver multipliers. A compact HUD carries it all.
• "Anything weird" flags — heuristic tripwires (FrontTuckRisk, ProfileDistortion, WashoutChange, SlackFabric, SpanLoss, UnderInflated, Asymmetry, SlackRow, Unsettled) calibrated across three dissimilar wings, with every dimensional threshold relative to the wing's own chord/span/airspeed so the calibration carries across sizes.
• Analyse… — sweeps the tunnel across an angle-of-attack range on a background thread (a fresh wing per point, settled to convergence) and reports shape integrity vs α: plots, the full table, every flag with its onset angle, CSV export.
• Settle — steps the live wing at the Accurate solver setting (60×4), unpaced, until the measurement converges — watch it happen under any heatmap — then pauses at the converged pose with a Done line carrying the numbers that matter (L/D, lift, worst deviation, flags).
• Pull any line — Ctrl-click a line junction and drag: a force-instrumented kinematic grab (pull distance and newtons in the HUD) for inducing collapses and probing recovery.
• Headless twins of every GUI number: softwing-bench --shape and --shape-sweep (CSV).

Ways of looking

• Four heatmaps, smoothly vertex-shaded: Stress (edge stretch), Shape deviation (mm from the aligned design shape), Slack fabric (compression — the wrinkle map) and Pressure (the pressure difference on every cell face, deliberately un-smoothed so the cell-by-cell inflation structure is visible — watch the wing inflate).
• A calibrated legend inside the viewport — the exact colour ramp with units, numeric ticks and a live peak marker; a peak beyond the scale parks at the top with its true value printed, so saturation reads as saturation.
• Strain maps measure fabric, not solver residual: pinning ties and sub-scale edges are excluded, and strains aggregate as length-weighted means.

The page

• Everything in a left panel, the viewport at full height (a wing is ~1:1; the window is ~2:1 — chrome belongs beside the picture, not above it), Design-style view buttons under it (Fit, Iso, Front, Back, Left, Right, Top, Bottom), one status line across the bottom. Fit frames the whole system — canopy and lines.
• Sliders that explain themselves — live readouts (Pressure in Pa and km/h, Angle in degrees, brakes in cm), and an angle-of-attack dial showing the set angle, the angle the wing actually holds, and the computed lift in newtons. Default tunnel speed 36 km/h.
• Simulation on its own thread — the camera, colour modes and sliders stay fluid at any mesh density; the picture updates whenever the solver delivers; rebuilds no longer freeze the app. Hardened by an adversarial concurrency review.

Free flight and structure

• The wing actually flies — free flight with a pilot slung under the risers, trimming at the angle the lines were designed for, launching on its glide. Steer with the brakes; a little symmetric brake steadies it. (Experimental, off by default.)
• Fly mode — the mouse is the brake input: top-centre hands-up, straight down both brakes, sideways releases the opposite brake. Esc exits. Also fixed: the Left brake slider used to pull the wing's right side.
• Detailed ribs (preference) — ribs meshed as real holed sheets instead of hub-and-spokes, so rib load means something; a dropped centreline rib fixed; a Reset button returns the wing to its rest pose.
• Dark-theme polish: check-box indicators and buttons are properly visible, with hover/checked/disabled states.

The claim boundary is documented in docs/playground-shape-analysis.md: relative, structural signals of one design and comparisons between revisions — not certified absolute aerodynamics.

Install

Platform	How
Windows	Download the winx64 zip, unzip anywhere, run LEparagliding.exe — self-contained, no install needed.
Linux	Download the AppImage, chmod +x it, run.
macOS	Download the DMG (signed and notarized), open it, drag the app to Applications.