# bspline_udp_2
# written by John Dannenhoffer

DESPMTR   dy        0.3

# make a NACA wing
UDPRIM    naca      series 0012
RESTORE   .
TRANSLATE 1  0  5
RULE

# extract the knot vectors and control points
EVALUATE  FACEUKT   @nbody       1
DIMENSION faceukt   @edata.size  1
SET       faceukt   @edata

EVALUATE  FACEVKT   @nbody       1
DIMENSION facevkt   @edata.size  1
SET       facevkt   @edata

EVALUATE  FACECP    @nbody       1
DIMENSION facecp    @edata.size  1
SET       facecp    @edata

# translate the y control points
PATBEG    i         facecp.size/3
   SET    facecp[3*i-1]  facecp[3*i-1]+dy
PATEND

# create a bspline surface with those knots and control points
UDPARG    bspline   uknots   faceukt
UDPARG    bspline   vknots   facevkt
UDPARG    bspline   cps      facecp
UDPRIM    bspline

END