[
    Fenetre(-1+i,1-i,5+5*i), LineStyle:=noline,
    L:=7, m:=4, sg:=if mod(m,2)=0 then 1 else -1 fi,
    P:= (for k from 0 to L do Anp(2*(L-k),L+m)*binom(L,k)*sg,0, sg:=-sg od)/(2^L*fact(L)),
    Del(P,L-m+2,0),
    K:=sqrt((2*L+1)*fact(L-abs(m))/(4*pi*fact(L+abs(m)))),
    NewMac("Plm",["[P:=",P,",T:=P[1],
        for k from 2 to Nops(P) do T:=x*T+P[k] od,
        T*(1-sqr(x))^(",m,"/2)]"],x),
    NewMac("Y",[K,"*Plm(cos(x))*cos(",m,"*y)"],x,y),
    S:=GetSurface( [z:=0.75+0.25*Y(v,u),z*exp(i*u)*sin(v),z*cos(v)],
               i*2*pi,i*pi,75+75*i),
    S1:=SortFacet(S,i),
    Map( 
        if Re(z)=Re(jump) then {facette}
            G:=isobar3d(facette),
            c:=(norm(G)-0.63)/(0.87-0.63), FillColor:=Rgb(1,1-c,0),
            Ligne3D([facette],1), facette:=Nil
        else 
            Insert(facette,z)
        fi, 
        z, S1
    )
]