# stiffener_udf_1
# written by John Dannenhoffer

DESPMTR   span      3.0
DESPMTR   angle     60.0
DESPMTR   depth     -.05
DESPMTR   nstiff    6

# create sheet (upper wing skin)
UDPRIM    naca   series  0025
EXTRUDE   0  0  span
SELECT    face   @nbody  3
EXTRACT   @sellist
STORE     unstiffened 0 1

# find the extents of the parametric coordinates
EVALUATE  faceinv  @nbody @nface  0  0  0
SET       ule      @edata[1]
SET       vroot    @edata[2]

EVALUATE  faceinv  @nbody @nface  1  0  span
SET       ute      @edata[1]
SET       vtip     @edata[2]

# add nstiff spanwise stiffners (ordered from leading edge to trailing edge)
PATBEG istiff nstiff
   SET       ustiff   ule-istiff/(nstiff+1)*(ule-ute)
   RESTORE   unstiffened
   UDPRIM    stiffener beg ustiff;vroot  end ustiff;vtip  angle angle  depth -depth
      ATTRIBUTE  stiffener $1
   UNION
PATEND

END