Hi Ramiro
Try
PerformanceGoal -> "Quality"
inside ContourPlot3D.
Alternatively:
t = Table[
ContourPlot3D[
x^2 + (4 + 1.2*z -
Abs[x]*Sqrt[(20 - Abs[x])/15])^2 + (y*(2 - z/15))^2 == (15 +
3 (1/2 + (1/2)*Sin[2*Pi*t0 + z/25])^4)^2, {x, -20,
20}, {y, -20, 20}, {z, -25, 25}, PerformanceGoal -> "Quality",
Mesh -> False,
ContourStyle ->
Directive[Red, Opacity[0.8], Specularity[White, 30],
PlotPoints -> 5, MaxRecursion -> 2]], {t0, 0, 2*Pi, \[Pi]/8}];
ListAnimate[t]
Robert
