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,1)*16.;
    p.zy*=rotate2D(t*.3);
    p.zy*=rotate2D(t*.3);
    for(j=0.;j++<4.;)
        p*=abs(mod(p,i/j/d)/4.)*rotate3D(j/i,vec3(2)),
        d=max(cos(p.y),tan(p.z))/d,
        d-=dot(p,p)/1e4;
    e-=d;
}o+=vec4(sqrt(p*i/e),1)*3./i;