Plotting RegionPlot3D within a certain radius

Question

I have a RegionPlot3D:

RegionPlot3D[
 Sin[1.5 (x - y)/Sqrt[2]]^2*Exp[-(z^2 + ((x + y)/Sqrt[2])^2)/2/20]  + 
   Sin[1.5 (x + y)/Sqrt[2]]^2*
    Exp[-(z^2 + ((x - y)/Sqrt[2])^2)/2/20] + 
   Sin[1.5 x]^2*Exp[-(z^2 + y^2)/2/20] + 
   Sin[1.5 y]^2*Exp[-(z^2 + x^2)/2/20] > 0.6, {x, -20, 20}, {y, -20, 
  20}, {z, -20, 20}, PlotPoints -> 100, 
 PlotStyle -> Directive[Orange, Specularity[White, 40]], Mesh -> None,
  Boxed -> False, Axes -> False]

I want to add bounds to the plot so as to only plot the result within some radius, so as not to get the cut-out circles at the corners:

Answer 1

f[x_, y_, z_]:= And[x^2 + y^2 + z^2 <= 300, 
  Sin[1.5 (x - y)/Sqrt[2]]^2*Exp[-(z^2 + ((x + y)/Sqrt[2])^2)/2/20] + 
   Sin[1.5 (x + y)/Sqrt[2]]^2*Exp[-(z^2 + ((x - y)/Sqrt[2])^2)/2/20] +
    Sin[1.5 x]^2*Exp[-(z^2 + y^2)/2/20] + Sin[1.5 y]^2*Exp[-(z^2 + x^2)/2/20]>.6]

RegionPlot3D[f[x, y, z], {x, -20, 20}, {y, -20, 20}, {z, -20, 20}, 
  PlotPoints -> 50, PlotStyle -> Directive[Orange, Specularity[White, 40]], Mesh -> None,
  Boxed -> False, Axes -> False]