Free software and open source codes written or supported by Frank C Lanngbein.

Feature Recognition with Database Optimisation
This code is an extension to PostgreSQL for finding CAD features efficiently. Development of this code has been supported by the Marie Curie Initial Training Network INSIST, funded by the 7th EU Framework Programme (FP7) under grant agreement n° 289361.

Efficient Feature Recognizer

Featured capacitor solution
This code is to estimate the simplification error. It’s an an extension to ngsolve / netgen to estimate the effect of model simplifications on a quantity of interest aimed at electrostatics problems.


This is software for denoising meshes using the technique described in our paper “Fast and Effective Feature-Preserving Mesh Denoising”. mdenoise-1.1.tar – Mesh Denoising Version 1.1. If you use this code please cite one of these publications:

Mesh Denoising Algorithm

FReg is the implementation of an algorithm to detect approximate symmetries of point sets and B-rep models. It has been developed as part of the Beautification of reverse engineered geometric models project. The algorithm has been implemented originally by B. I. Mills. I am currently maintaining the sources. The main […]


SiL is an environment for geometric modelling applications. It’s core is an object manager especially tailored for geometric objects. It can load modules dynamically to provide the object types and the basic functionality for these objects. In addition tools can be added as plugins to provide a user front-end to […]


Twisted Eight
LiLit is a program to visualize functionals on freeform surfaces. It uses biquadratic g-splines to display surfaces and functions, which are defined by a control mesh for the surface and the function from some file in a special input format. It can run the Doo-Sabin subdivision algorithm on the control […]


PIDS is an algorithm for simplifying mathematical expressions, implemented in emacs lisp. pids-1.0.tar.gz – PIDS Version 1.0. If you use this code please cite