Deltographos::Blog

float i,j,d=.01,e; vec3 p;
for(i=0.;i++<64.&&d>1e-4;){
    p=vec3((FC.xy-.5*r)/r.y,e/5.)*2.;
    p*=rotate3D(t,vec3(-4,2,4));
    for(j=0.;j++<4.;)
        p=abs(p*p*rotate3D(i/j,vec3(4,2,4))),
        d=max((length(p.zy)),(length(p.zx)))/d,
        d-=dot(p/i,-p/i)/d;
    e-=d;
}o+=vec4(exp(-p/e/d),1)*3./i;