PHOTON USE
  P
  PHI
 
  X1
 
 
 
  msg(  PLANT BFC grid and sphere
  rot y ang 100;rot z ang 30
  surf MARK Z 0.99
  gr z m;gr ou y m
  gr y m z 1 2
  ENDUSE
  >>>>>>>>>>>>>>>>>>>>>> Comment begins >>>>>>>>>>>>>>>>>>>>

  DISPLAY 
    This input  demonstrates  that  the   "drilling-milling"
    technique  available  in PLANT can be used also with BFC
    grids.  The combination of BFC  with  blocking-off  some
    cells  to fit extra geometrical features,  may bring the
    number of practical advantatges.
 
    In this  case  the   sphere   and   cylinder   will   be
    "drilled-out" in the beam of asteroidal cross section.
  ENDDIS
 
    PLANT information :
     * Data input groups used: 6, 19
     * Ground groups planted : 1, 19-2, 19-6
     * Headings used  : MXYZ??, SC06??
     * Functions used : SPHERE, XYCIRC
     * Commands used  : REGION
 
  <<<<<<<<<<<<<<<<<<<<<<< Comment ends <<<<<<<<<<<<<<<<<<<<<
TEXT( Drilling star-shaped space
 
    GROUP 6. Body-fitted coordinates or grid distortion
nx=28;ny=20;nz=40
bfc=t
dumpc(grid);readco(grid) 
CSG1=PHI;CSG2=XYZ;lsweep=1;IDISPA=1
SOLVE(MARK)
FIINIT(MARK)=0.
NAMSAT=MOSG

     PLANTBEGIN
real(twopi,littler)
littler=1.0;twopi=2.0*3.14157
RG(1)=TWOPI
    ** Calculate BFC star-shaped grid 
    XC=:LITTLER:*FLOAT(J-1)/FLOAT(NY)*$
            COS(RG(1)*FLOAT(I-1)/FLOAT(NX))**3
    YC=:LITTLER:*FLOAT(J-1)/FLOAT(NY)*$
            SIN(RG(1)*FLOAT(I-1)/FLOAT(NX))**3
    ZC=5*FLOAT(K-1)/FLOAT(NZ)
    ** Drill the sphere
   MARK=SPHERE(1.,0.,0.,4.0,0.6)
    ** Drill the cylinder
   MARK=XYCIRC(1.,0.,0.,0.3)
   REGION(,,,,9,20)
  >>>>>>>>>>>>>>>>>>>>>> Comment begins >>>>>>>>>>>>>>>>>>>>
    The use  of  SPHERE,  XYCIRC   and   other   geometrical
    functions is similar to cartesian cases.  The difference
    is  that  arguments  must  be  specified  in  terms   of
    reference cartesian coordinate system.  The latter is of
    routine use for all BFC problems.
  <<<<<<<<<<<<<<<<<<<<<<< Comment ends <<<<<<<<<<<<<<<<<<<<<
    PLANTEND

dmpstk=t
DISTIL=T
EX(MARK)=2.800E-01
 LIBREF=601
STOP