How to visualize/export deformed FFD after shape optimization (DAFoam v4+)

[rrestoy]

Hi everyone,

I am currently learning to use DAFoam for aerodynamic shape optimization, mainly by running and modifying the tutorial cases (e.g. NACA airfoil cases) to better understand the full workflow with FFD-based shape parameterization.
I have read the available DAFoam user documentation, the FFD-related resources, and several GitHub discussions, but I am still unclear about one specific point.
After an optimization converges, I would like to visualize or export the deformed FFD itself, not only the deformed surface or mesh. My goal is to verify that the final shape deformation is consistent with the intended FFD control-point movements, and to better understand how the geometry deformation propagates from the FFD to the design surface.
At the moment, I can see the deformed geometry and mesh in ParaView, but I cannot figure out:

• how to see the deformation of the FFD as optimization progresses, to see the final shape and the shift between the initial form of the FFD and its final form
• Is there a simple option (such as an addition to the runScript.py code) that allows you to extract and save the evolution of the FFD throughout the optimization loops?

Could you please clarify:

1. How one can visualize the deformation of the FFD as the optimization progresses, in order to observe the final FFD shape as well as the displacement between the initial and final FFD configurations.
   2 ) Whether there is a simple option or recommended modification (for example an addition to the runScript.py) that allows one to extract and save the evolution of the FFD throughout the optimization iterations, or if this must be done manually using DVGeo and the design variables.

Thank you very much for your time.
Best regards,

[friedenhe]

Set writeDeformedFFDs to true. Check:

dafoam/tests/runRegTests_AeroOpt.py

Line 41 in 31433b4

"writeDeformedFFDs": True,

You also need to add a line later in the runScript.py. Check:

dafoam/tests/runRegTests_AeroOpt.py

Line 142 in 31433b4

self.cruise.coupling.solver.add_dvgeo(self.geometry.DVGeo)