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)*24.;
    p.z-=.1;
    p*=rotate3D(t,vec3(-2))-.5;
    for(j=0.;j++<4.;)
        p=abs(p-.5)*rotate3D(j/i,vec3(2))-1.2,
        d=max(min(p.z,p.y),dot(p.x,p.y))/e,
        d-=dot(p,p)/1e4;
    e+=d;
}o+=vec4(exp(-p/i-.5),1)*3./i;