\pstGeonode[PosAngle={0,90}](2,2){A_0}(-2,2){B_0}%
\psset{RotAngle=90}
\pstRotation[PosAngle=270]{A_0}{B_0}[D_0]
\pstRotation[PosAngle=180]{D_0}{A_0}[C_0]
\pspolygon(A_0)(B_0)(C_0)(D_0)%
\psset{PointSymbol=none, PointName=none, HomCoef=.2}
\multido{\n=1+1,\i=0+1}{20}{%
  \pstHomO[PosAngle=0]{B_\i}{A_\i}[A_\n]
  \pstHomO[PosAngle=90]{C_\i}{B_\i}[B_\n]
  \pstHomO[PosAngle=180]{D_\i}{C_\i}[C_\n]
  \pstHomO[PosAngle=270]{A_\i}{D_\i}[D_\n]
  \pspolygon(A_\n)(B_\n)(C_\n)(D_\n)}% fin multido

