Deltographos::Blog

float i,j,d=.001,e; vec3 p;
for(i=0.;i++<64.&&d>1e-4;){
    p=vec3((FC.xy-.5*r)/r.y,e)*1.2;
    p*=rotate3D(t,vec3(-1,4,2));
    for(j=0.;j++<4.;)
        p=abs(p*p/.645)*rotate3D(t,vec3(-1,8,8)),
        p.zy*=rotate2D(t),
        d=max(tan(length(p.xz)),sin(length(p.zy)))*d,
        d-=dot(p,p)/d;
    e-=sqrt(d);
}o+=vec4(log(p/i/d),1)*8./i;