Deltographos::Blog

float i,j,d=.1,e; vec3 p;
for(i=0.;i++<64.&&d>1e-4;){
    p=vec3((FC.xy-.5*r)/r.y,e)*4.;
    p*=rotate3D(t,vec3(-1,0,1));
    for(j=0.;j++<4.;)
        p=abs(p*p)*rotate3D(i/j,vec3(2,-4,6))/d,
        p.xz*=rotate2D(t*.5),
        p.zy*=rotate2D(t*.5),
        d=max((length(p.xz/5.)),(length(-p.zy)))/d,
        d-=dot(p,-p)/1e4;
    e-=d;
}o+=vec4(exp(-p*p*i),1)*3./i;