I recently installed FreeFem because I am interested in the 3d mesh adaption routines (very satisified with that so far).
My problem right now is, that I want to solve a 3 dimensional PDE (with a scalar solution “u”) but I want to have boundary condition on the 2d surface where u=u_fix (just for the next time step).
Is there a smart (efficient) way to extract the iso mesh computational efficient and include a “int2d” boundary condition (du/dn=f(x,y,z))
(I have some Fortran code of my “old” naive solution without adaptive mesh algorithms, but I am not “willing” to port my bad code to FF++).
I know the 2d isoline function (but to my knowledge nothing like this exists for 3d).
Every bit of help is appreciated!