https://twitter.com/zozuar/status/1446860112086319106

#define R rotate2D for(float i,j,g,e,s;i++<1e2;g+=e*.1){vec3 p=vec3((FC.xy-.5r)/r.yg,g-2.);p.yz*=R(5.1+cos(t).3);p.xz=R(t);for(e=j=17.;j-->-2.;e=min(e,p.y+(abs(cos(p.xsPI))+sin(p.zsPI))/s))s=exp(j*.5-fract(t/PI)3.),p.xz=R(PI/3.);o+=exp(-e*1e3)/70.;} // bit.ly/3uYL9K9