FFD point inversion

Generated from SU2 commit 6b54b78464 on 2026-10-23. Do not edit this page. Edit the comment above the option in Common/src/CConfig.cpp instead.

FFD_FIX_I

Fix I plane

More in config_template.cfg: Definition of the FFD planes to be frozen in the FFD (x,y,z). Value from 0 FFD degree in that direction. Pick a value larger than degree if you don’t want to fix any plane.

• Type: list of integers
• In config_template.cfg: FFD_FIX_I= (0,2,3)
• Mentioned in: Setup Guide: Shape Optimization with the Discrete Adjoint, Unconstrained shape design of a two way mixing channel
• Used in 3 test case files, for example: lam_prem_ch4_cht_ad_master.cfg ((100)), inv_NACA0012_ffd.cfg ((0,4))
• Code: CConfig.cpp line 2955

FFD_FIX_J

Fix J plane

• Type: list of integers
• In config_template.cfg: FFD_FIX_J= (0,2,3)
• Mentioned in: Setup Guide: Shape Optimization with the Discrete Adjoint, Unconstrained shape design of a two way mixing channel
• Used in 3 test case files, for example: lam_prem_ch4_cht_ad_master.cfg ((100)), inv_NACA0012_ffd.cfg ((15))
• Code: CConfig.cpp line 2958

FFD_FIX_K

Fix K plane

• Type: list of integers
• In config_template.cfg: FFD_FIX_K= (0,2,3)
• Mentioned in: Setup Guide: Shape Optimization with the Discrete Adjoint, Unconstrained shape design of a two way mixing channel
• Used in 1 test case file, for example: inv_NACA0012_ffd.cfg ((15))
• Code: CConfig.cpp line 2961

FFD_SYMMETRY_PLANE

FFD symmetry plane (j=0)

More in config_template.cfg: There is a symmetry plane (j=0) for all the FFD boxes (YES, NO)

• Type: YES / NO
• Default: NO
• In config_template.cfg: FFD_SYMMETRY_PLANE= NO
• Mentioned in: Setup Guide: Shape Optimization with the Discrete Adjoint
• Code: CConfig.cpp line 2964

FFD_COORD_SYSTEM

Define different coordinates systems for the FFD

More in config_template.cfg: FFD coordinate system (CARTESIAN)

• Type: one of the values below
• Values: CARTESIAN, CYLINDRICAL, SPHERICAL, POLAR
• Default: CARTESIAN
• In config_template.cfg: FFD_COORD_SYSTEM= CARTESIAN
• Mentioned in: Setup Guide: Shape Optimization with the Discrete Adjoint
• Used in 3 test case files, for example: def_cylindrical.cfg (CYLINDRICAL), def_spherical.cfg (SPHERICAL)
• Code: CConfig.cpp line 2967

FFD_AXIS

Axis information for the spherical and cylindrical coord system

More in config_template.cfg: Vector from the cartesian axis the cylindrical or spherical axis (using cartesian coordinates) Note that the location of the axis will affect the wall curvature of the FFD box as well as the design variable effect.

• Type: fixed-size list of real numbers
• Default: Not extracted; see the code.
• In config_template.cfg: FFD_AXIS= (0.0, 0.0, 0.0)
• Mentioned in: Setup Guide: Shape Optimization with the Discrete Adjoint
• Used in 3 test case files, for example: def_cylindrical.cfg ((0.0, 0.0, 0.0))
• Code: CConfig.cpp line 2971

FFD_ITERATIONS

Number of total iterations in the FFD point inversion

More in config_template.cfg: Maximum number of iterations in the Free-Form Deformation point inversion

• Type: integer
• Default: 500
• In config_template.cfg: FFD_ITERATIONS= 500
• Mentioned in: Setup Guide: Shape Optimization with the Discrete Adjoint, Constrained shape design of a transonic inviscid wing at a cte. C_L, Shape Design With Multiple Objectives and Penalty Functions, Unconstrained shape design of a two way mixing channel
• Used in 45 test case files, for example: inv_ONERAM6.cfg (500), inv_ONERAM6_moving.cfg (1000), disc_adj_heat.cfg (100)
• Code: CConfig.cpp line 2974

FFD_TOLERANCE

Free surface damping coefficient

More in config_template.cfg: Tolerance of the Free-Form Deformation point inversion

• Type: real number
• Default: 1E-10
• In config_template.cfg: FFD_TOLERANCE= 1E-10
• Mentioned in: Setup Guide: Shape Optimization with the Discrete Adjoint, Constrained shape design of a transonic inviscid wing at a cte. C_L, Shape Design With Multiple Objectives and Penalty Functions, Unconstrained shape design of a two way mixing channel
• Used in 45 test case files, for example: inv_ONERAM6.cfg (1E-10), inv_ONERAM6_moving.cfg (1E-8), def_brick_hex.cfg (1E-15)
• Code: CConfig.cpp line 2977

FFD_INTPREV

Procedure to prevent self-intersections within the FFD box based on Jacobian determinant

More in config_template.cfg: Parameters for prevention of self-intersections within FFD box

• Type: YES / NO
• Default: NO
• In config_template.cfg: FFD_INTPREV = YES
• Mentioned in: Setup Guide: Shape Optimization with the Discrete Adjoint
• Used in 1 test case file, for example: def_intersect.cfg (YES)
• Code: CConfig.cpp line 2980

FFD_INTPREV_ITER

Number of total iterations in the convexity check procedure

• Type: integer
• Default: 10
• In config_template.cfg: FFD_INTPREV_ITER = 10
• Mentioned in: Setup Guide: Shape Optimization with the Discrete Adjoint
• Used in 1 test case file, for example: def_intersect.cfg (2)
• Code: CConfig.cpp line 2983

FFD_INTPREV_DEPTH

Recursion depth in the FFD self-intersection prevention

• Type: integer
• Default: 3
• In config_template.cfg: FFD_INTPREV_DEPTH = 3
• Mentioned in: Setup Guide: Shape Optimization with the Discrete Adjoint
• Used in 1 test case file, for example: def_intersect.cfg (3)
• Code: CConfig.cpp line 2986

CONVEXITY_CHECK

Convexity check on all mesh elements

More in config_template.cfg: Parameters for prevention of nonconvex elements in mesh after deformation

• Type: YES / NO
• Default: NO
• In config_template.cfg: CONVEXITY_CHECK = YES
• Used in 1 test case file, for example: def_intersect.cfg (YES)
• Code: CConfig.cpp line 2989

CONVEXITY_CHECK_ITER

Number of total iterations in the convexity check procedure

• Type: integer
• Default: 10
• In config_template.cfg: CONVEXITY_CHECK_ITER = 10
• Used in 1 test case file, for example: def_intersect.cfg (10)
• Code: CConfig.cpp line 2992

CONVEXITY_CHECK_DEPTH

Recursion depth in the FFD self-intersection prevention

• Type: integer
• Default: 3
• In config_template.cfg: CONVEXITY_CHECK_DEPTH = 3
• Used in 1 test case file, for example: def_intersect.cfg (3)
• Code: CConfig.cpp line 2995

FFD_DEFINITION

Definition of the FFD boxes

More in config_template.cfg: FFD box definition: 3D case (FFD_BoxTag, X1, Y1, Z1, X2, Y2, Z2, X3, Y3, Z3, X4, Y4, Z4, X5, Y5, Z5, X6, Y6, Z6, X7, Y7, Z7, X8, Y8, Z8) 2D case (FFD_BoxTag, X1, Y1, 0.0, X2, Y2, 0.0, X3, Y3, 0.0, X4, Y4, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0)

• Type: special format, see config_template.cfg
• In config_template.cfg: FFD_DEFINITION= (MAIN_BOX, 0.5, 0.25, -0.25, 1.5, 0.25, -0.25, 1.5, 0.75, -0.25, 0.5, 0.75, -0.25, 0.5, 0.25, 0.25, 1.5, 0.25, 0.25, 1.5, 0.75, 0.25, 0.5, 0.75, 0.25)
• Mentioned in: Setup Guide: Shape Optimization with the Discrete Adjoint, Adjoint design optimization of a turbulent 3D pipe bend, Constrained shape design of a transonic inviscid wing at a cte. C_L, Shape Design With Multiple Objectives and Penalty Functions, Unconstrained shape design of a two way mixing channel
• Used in 42 test case files, for example: inv_ONERAM6.cfg ((MAIN_BOX, -0.0403, 0.0, -0.04836, 0.8463, 0.0, -0.04836, 1.209, 1.2896, -0.04836, 0.6851, 1.2896, -0.04836, -0.0403, 0.0, 0.04836, 0.8463, 0.0, 0.04836, 1.209, 1.2896, 0.04836, 0.6851, 1.2896, 0.04836)), inv_wedge_ROE.cfg ((MAIN_BOX, 0.5, -0.25, 0, 1.5, -0.25, 0, 1.5, 0.25, 0, 0.5, 0.25, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0)), chtMaster.cfg ((BOX,\)
• Code: CConfig.cpp line 2998

FFD_DEGREE

Definition of the FFD boxes

More in config_template.cfg: FFD box degree: 3D case (i_degree, j_degree, k_degree) 2D case (i_degree, j_degree, 0)

• Type: special format, see config_template.cfg
• In config_template.cfg: FFD_DEGREE= (10, 10, 1)
• Mentioned in: Setup Guide: Shape Optimization with the Discrete Adjoint, Adjoint design optimization of a turbulent 3D pipe bend, Constrained shape design of a transonic inviscid wing at a cte. C_L, Shape Design With Multiple Objectives and Penalty Functions, Unconstrained shape design of a two way mixing channel
• Used in 42 test case files, for example: inv_ONERAM6.cfg ((10, 8, 1)), inv_wedge_ROE.cfg ((10, 1,0)), chtMaster.cfg ((8, 1, 0))
• Code: CConfig.cpp line 3001

FFD_CONTINUITY

Surface continuity at the intersection with the FFD

More in config_template.cfg: Surface grid continuity at the intersection with the faces of the FFD boxes. To keep a particular level of surface continuity, SU2 automatically freezes the right number of control point planes (NO_DERIVATIVE, 1ST_DERIVATIVE, 2ND_DERIVATIVE, USER_INPUT)

• Type: one of the values below
• Values: NO_DERIVATIVE, 1ST_DERIVATIVE, 2ND_DERIVATIVE, USER_INPUT
• Default: 2ND_DERIVATIVE
• In config_template.cfg: FFD_CONTINUITY= 2ND_DERIVATIVE
• Mentioned in: Setup Guide: Shape Optimization with the Discrete Adjoint, Adjoint design optimization of a turbulent 3D pipe bend, Constrained shape design of a transonic inviscid wing at a cte. C_L, Shape Design With Multiple Objectives and Penalty Functions, Unconstrained shape design of a two way mixing channel
• Used in 40 test case files, for example: inv_ONERAM6.cfg (2ND_DERIVATIVE), chtMaster.cfg (NO_DERIVATIVE), def_brick_hex.cfg (1ST_DERIVATIVE)
• Code: CConfig.cpp line 3004

FFD_BLENDING

Kind of blending for the FFD definition

More in config_template.cfg: FFD Blending function: Bezier curves with global support (BEZIER), uniform BSplines with local support (BSPLINE_UNIFORM)

• Type: one of the values below
• Values: BSPLINE_UNIFORM, BEZIER
• Default: BEZIER
• In config_template.cfg: FFD_BLENDING= BEZIER
• Mentioned in: Setup Guide: Shape Optimization with the Discrete Adjoint
• Used in 4 test case files, for example: def_spherical_bspline.cfg (BSPLINE_UNIFORM)
• Code: CConfig.cpp line 3007

FFD_BSPLINE_ORDER

Order of the BSplines for BSpline Blending function

• Type: fixed-size list of real numbers
• Default: Not extracted; see the code.
• In config_template.cfg: FFD_BSPLINE_ORDER= 2, 2, 2
• Mentioned in: Setup Guide: Shape Optimization with the Discrete Adjoint
• Used in 4 test case files, for example: def_spherical_bspline.cfg (2, 2, 2), disc_adj_heat.cfg (4,4,2), configMaster.cfg (4,3,2)
• Code: CConfig.cpp line 3011