[Insight-developers] FEM loads

[Huai-Ping Lee]

Hello,

I'm trying to debug the examples for FEMRegistrationFilter
(Examples/Registration/DeformableRegistration1.cxx and
DeformableRegistration11.cxx), which have been disabled due to API
changes in ITK4. I found that the image-based loads in the FEMObject
are always ignored, and the registration does nothing as a result.
Actually, in the function itk::fem::Solver::ApplyBC(), only LoadBCMFC
and LoadBC are considered, and all other kinds of loads are ignored
(which means external forces are ignored). Also, in
SolverCrankNicolson::AssembleKandM(), I see a comment asking if
there's a bug in ApplyBC().

In addition, I couldn't find any test for the image-based loads
(FiniteDifferenceFunctionLoad and ImageMetricLoad).

Without these components, FEMRegistrationFilter cannot work. I'll need
help from experts in these classes. Is anyone working on the FEM
module?

Thanks.

--
Huai-Ping Lee
Kitware, Inc.