python library to build paragliders

booya-at, updated 🕥 2023-01-01 18:53:30


Build Status Coverage Status Documentation Status

A future open source paraglider design software (still a WIP)

Try It

Clone the git-repo first: bash git clone

Install with pip

bash cd OpenGlider pip install -e .

Or manually install all dependencies (using distro-repos, easy_install or pip) * ezodf2 * dxfwrite * scipy * (svgwrite) * (vtk)

Install with conda

We are providing packages of OpenGlider and dependencies via conda. To install conda download miniconda and follow the install instructions. Once you have a working base-environment you can create a new environment for openglider:
bash conda create -n openglider openglider freecad meshpy -c conda-forge


Every module inside openglider should have a README where the functionality is documented.
Please have a look at the base module.

Also have a look at the gui-tutorial

Unittests and Visual Tests

To run all unittests, run this from the main directory: bash ./

Or use -a flag to also run visual tests bash ./ -a

Development Screenshots

While still being in an early status, here are a few screenshots showing progress made so far:

screenshot gui glider workbench gui

screenshot testcell with miniribs testcell with miniribs

screenshot demokite with central minirib demo kite with central minirib

screenshot demokite plots demo kite plots

plots plots


The plan is to build on the following technologies:

  • Python (link)

  • self-coded panelmethod (VSAERO) and/or apame implementation (link) for quick 3D-calculation (see parabem)

  • OpenFoam obj-file CFD export

  • paraFEM - Explicit non linear FEM (membrane, truss) for line forces and deformation analysis

  • FreeCAD (Open-Source Cad, written in c++ with python API

  • VTK - visual toolkit for 3d-output

  • ~~Code_Aster FEM export ( - maybe calculix as we've done already, but it does currently not support membrane elements)~~

  • ~~xfoil//Pyxfoil for 2D-foil calculation ( (

It will take some time, if you want to help, feel free to do so!

Using some older code, we already created a few prototypes which can be seen on


Rib Holes misplaced/weird logic

opened on 2022-11-28 14:51:43 by AffiFPV

When I try to use the "create holes" feature it only creates holes above attachment points, which I think should be the opposite to place holes "everywhere" but above them. image image (isn't a zip, just remove .zip to get the FCStd) Also is there a way to remove/edit the holes remaining from the stock wing? I tried to find an obvious solution in the code ( & but didn't fully understand where the placement is calculated.

unwrap breaks under some circumstances

opened on 2022-03-23 13:30:37 by j2l

I just had the exact same error as, At the end, it throws Cannot normalize a vector of length 0.0 ... but I found that it happens under a specific process: ...->unwrap->modify->unwrap

On Ubuntu 21.10, FreeCAD FreeCAD_0.19.3-Linux-Conda_glibc2.12-x86_64.AppImage To be clear: I add the default glider, unwrap it, it works. Then I modify it and try to unwrap, it fails. From there, if I create a new document and add a new glider and unwrap, it fails. If I quit and relaunch FreeCAD, add default glider, MODIFY it and unwrap it works. If I modify it again and unwrap it fails. If I now save the (failing) glider, quit and relaunch FreeCAD, open the saved glider and unwrap it works ...

So unwrap might write something somewhere at first unwrap that is read at second unwrap, if you modify something in between unwraps, it fails. Only saving, quitting FreeCAD and reopening to unwrap again works (it basically can't read the previous unwrap var somewhere). But you know you can't unwrap anymore after this one, you'd better be sure you want to unwrap it :)

Glider breaking freecad weekly

opened on 2022-03-02 01:05:07 by KenwoodFox

Hello! it looks like glider might be causing issues in the freecad weekly bundle?

If i can help in any way lmk!

Only half wing

opened on 2022-02-25 08:02:05 by sandra-walker

Good day

I have the problem that I have only half the wing on the plot. The values are also only transferred to half the wing area. See screenshot wind .

No plots on polars feature

opened on 2021-11-26 10:07:54 by PhilippAumann


once I open the polars feature to create plots for aerodynamic calculations, the "create plots" button does not seem to have an effect. How can I check if there are plots created somewhere?

I am using conda 4.10.3 with Python 3.8.12 on macOS Catalina.

Installation: Old curl version as dependency?

opened on 2021-11-26 10:01:01 by PhilippAumann


thank you for providing this very nice toolbox :) By the way, I am also a paragliding pilot located in Tyrol.

I installed OpenGliger via conda as explained in the Readme. However I couldn't get freecad running as it returned bash dyld: Library not loaded: @rpath/libcurl.4.dylib Reason: Incompatible library version: libxerces-c-3.2.dylib requires version 12.0.0 or later, but libcurl.4.dylib provides version 11.0.0 Abort trap: 6 This issue could be resolved by running bash conda update curl

This might be fixed by requesting the newst version of curl as a dependency?

I am using conda 4.10.3 with Python 3.8.12 on macOS Catalina.

Releases 2021-11-04 16:27:18

minor fix for unwrapping

0.0.7 2021-09-28 10:36:05

minor windows fix

0.0.6_cpp4 2021-01-25 19:16:54

0.0.6_cpp2 2021-01-25 18:53:44

0.0.6_cpp 2021-01-20 19:28:25

testing the cpp stuff

0.0.6_cpp7 2021-01-19 11:14:44


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