Get the equation/data of the hinge line of a control surface / subsurface

[Etienne Behar]

Hello everyone,

    Short version: is there a way to retrieve the equation, the vector, or any sort of data, describing the hinge line defined by a subsurface of type Control_surf, such as shown on this attached snapshot? I am mostly working with python API, but if necessary I could go to the extent of compiling the source. This vector must exist at some point, somewhere, in some variable!

    More context: like many other before me (it seems), I am replacing these control surfaces by separate geometries, the end goal being to deflect these surfaces by any angle, small or large, before any meshing operation. And deal automatically with various models and varying surfaces dimensions. Creating the geometries is fine (see the second attached snapshot), but retrieving the hinge line, aligning a hinge geom there which would allow me to rotate cleanly these surfaces, without manual manipulation on the GUI, turns out to be more difficult. If any one went through the same struggle, found a workaround, or if a "automagical" piece of script already exists out there, please tell me!

    Despite lengthy searches on the Group, I couldn't find anything close to what I am looking for. 

Thank you for your time and help!

Etienne.

[Rob McDonald]

The hinge line endpoints are the mid-points between the corners of the control surface.  You can probably construct them easily that way in your CAD tool.

Otherwise, they are written out to the DegenGeom file -- you can run the Degenerate Geometry analysis and write out the *.csv and/or *.m files and find the data in there.

Rob