Dear OpenMesh developers, I am working on a Vertex Model code. Vertex Model is one of the standard models for epithelial tissue mechanics. The tissue is modelled as a polygonal tessellation of the plane making the half-edge data structure ideal for implementing it. One of the key ingredients in modelling tissue mechanics is describing the so-called T1- transition. Briefly, for a quadruplet of cells labelled as 1,2,3 and 4, cells 1 and 2 are neighbours (share an edge). During the T1 transition, this edge shrinks and collapses to a point (a four-vertex). This vertex is then resolved (split) in the opposite direction, such that cells 3 and 4 now share an edge and cells 1 and 2 are no longer in contact. T1 can also be seen as what happens to the dual of a Delaunay triangulation when an edge is flipped due to the angle criterion being violated. If I am not mistaken, at the moment vertex split is supported only for triangular meshes. How hard would it be to implement it for a general polygonal mesh? (Unfortunately, it is not possible to work with triangular meshes as it would lead to very serious complications with force calculations.) At the moment I have my own light-weight C++11 implementation of the half-edge data structure that does this. However, using OpenMesh would be far more appealing due to its many powerful features. Many thanks, Rastko ________________________________________ Rastko Sknepnek Senior Lecturer in Physics School of Science and Engineering School of Life Sciences University of Dundee Discovery Centre, Room 2.28 Dundee DD1 5EH, UK +44 (0) 1382 385699 The University of Dundee is a registered Scottish Charity, No: SC015096