# guide_udf_1
# written by John Dannenhoffer

DESPMTR   rad   2.0
DESPMTR   dz    3.0

# constant cross-section
SKBEG       -.5  -.5  0.0
   LINSEG   0.0  -.5  0.0
   CIRARC   0.5  0.0  0.0  0.0  0.5  0.0
   LINSEG   -.5  0.5  0.0
SKEND

# guide curve
SKBEG        rad              0.0              0.0
   PATBEG    isect  8
      SET    theta  min(isect*45,180)
      SPLINE rad*cosd(theta)  rad*sind(theta)  isect*dz
   PATEND
SKEND

UDPARG    guide     nxsect  17
UDPRIM    guide     origin  "0;0;0"   # xsect point to put on guide curve

END