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(x' is x - xCenter etc)
R = sqrt(x'*x'+y'*y'+z'*z')/Rmax;
if inside==1 {
// simple mode, out Mandel and in Julia.
if R < 1 {
  R -= Speed
  if R > 0 {      // Transition
    // never get here if R==0 or you get in trouble!...
    R /= (1-Speed);
    Cx = (1-R) * Sx + R * Cx;
    Cy = (1-R) * Sy + R * Cy;
    Cz = (1-R) * Sz + R * Cz;
    rc = rec*(1-R);
    x -= rc*xC;
    y -= rc*yC;
    z -= rc*zC;
  } else {      // inside must be Julia
    rc = rec;
    Cx = Sx;    Cy = Sy;    Cz = Sz;
    x -= rc*xC; y -= rc*yC; z -= rc*zC; // implemented with a GOTO
}}  // outside is left untouched
} else {
// alternate mode, out Julia and in Mandel. Longer formula
if R < 1 {
  R -= Speed
  if R > 0 {      // Transition
    // never get here if R==0 or you get in trouble!...
    R /= (1-Speed);
    Cx = (1-R) * (Cx-rec*xC) + R * Sx;
    Cy = (1-R) * (Cy-rec*yC) + R * Sy;
    Cz = (1-R) * (Cz-rec*zC) + R * Sz;
    rc = rec*(1-R); // implemented with a GOTO
    x -= rc*xC;
    y -= rc*yC;
    z -= rc*zC;
  } else {      // inside must be shifted Mset
    Cx = Cx-rec*xC;
    Cy = Cy-rec*yC;
    Cz = Cz-rec*zC;
    rc = rec; // implemented with a GOTO
    x -= rc*xC; y -= rc*yC; z -= rc*zC;
}} else {   // (R>=1 is outside)
  // outside must be unshifted Julia with given seed!
  Cx = Sx;
  Cy = Sy;
  Cz = Sz;
}

} // end

Mandelbulb3Dv17{
R.....S....O/...w....2.....Pzvsb0nQA.jW9bwmE1l4EH9Zzy7GytzvWNGiOWJtjzG9SoM1Bjw.k
................................gAY93cAPGz1........Y./..................y.2.....
................/M.0/....6.V/...O0....E2.....6utp4VMWysD/..........m/dkpXm1....U
z.UaNadD12../..........wz..................................u1....y1...sD...../..
.w1...sDwCv1HZRL4y1/i1SdJAZgyGsd78czSNsjM41QRifCZr9DEuk1W7uXzkhkwEUAebfjlYTO2ujL
4y1/i1SdJAZgyMLGj2JqRNsD......Y2..............kD.2....sD.2kz0...................
.............oAnAr1...........JRW4.wp7O.EObc/.nRW4.or7O.kVbc/.FSW4..............
..................kz.wzzz1.U..6.P....M4...EB....W....k1....F....8/...I1....UJl42
...U.qFG9yzb2zzzRYoWzz7lz16.mc..zXCc.El18XGQeGyDjvIRhrVAkz1..........2.28.kFrA0.
FWb96aAIVzvh1se7Umvxz0........../6U0.wzzz1................................E.0c..
zzzz.................................2U.8.kzzzD.................................
/6U0.wzzz1...................................2CcN/UvNP6.eeWCNq0.yRii.EJJUk1f..XR
S1.mx3CcN/UvNP6.QsLsUa3.ibhV..bTV1OK.sSq40.ly3CcN/UvNP6.MwLsUa3.ibhV.kqTV1OK.sSq
40.kz3CcN/UvNP6...EsUa3.eeWCNq0.IJ36wk8.wyLsUa3.................................
E....6....E.....I....c....kLE3aQolKS8J5Pd3aI....................................
0.......................................6.A........6.dNaNaNaNayD................
...0.1........0E........kz1........wz0..........................................
.....................2...../....1....2IPVdLOiR460x4S.65.........................
.Qk0...........................E........Uz1........wz...........................
................................................................................
................................}

R = sqrt(x'*x'+y'*y'+z'*z')/Rmax; // Euclidean metric (sphere)
// Cubic metric (not euclidean but funny);
// x' = abs(x'); y' = abs(y'); z' = abs(z'); 
// R = max(x',y',z')/Rmax;
// Biconical metric;
// R = sqrt((x'*x'+y'*y')/(z'*z'))/Rmax; <- rmax controls the pendence
// Cylindrical metric;
// R = sqrt(x'*x'+y'*y')/Rmax;