[flyyufei]

In the ONERA M6 optimization test case (V3.0.00 test case folder: TestCases\optimization_rans\steady_oneram6\), the grid file (mesh_ONERAM6_turb.su2) includes the FFD control parameters.
The “FFD_CORNER_POINTS” and “FFD_CONTROL_POINTS” is easy for understanding. But the “FFD_SURFACE_POINTS” is quite confusing. The point indexes are the indexes of the wing surface grid, but the coordinates are not on the wing surface (as shown in the figure).

Is the FFD_SURFACE_POINTS necessary? Is there any tutorial for the FFD definition?

When I use the FFD function with my own grid, the SU2_MDC couldn’t generate the deformed mesh, because the maximum difference of the original and deformed surface grids is very large, even when all of the geometry parameters are 0. I think the problem comes from the FFD_SURFACE_POINTS definition.

Thank you for your help!