float i,j,g,e,s,k=sin(t);for(vec3 q,p;i++<2e2;p=q+=i>1e2?p-p+(e*.2+1e-6)vec3(1,0,-1):vec3((FC.xy-.5r)/r.y,1)e.1){p.z-=.4,p+=k*.1;p*=rotate3D(5.3,vec3(5,k2.,1));e=p.y;for(j=8.;j-->0.;e+=min(.0,dot(abs(cos(p.xzsPI))-.5,r/r)/s.5))s=exp(j-fract(t/PI*4.));}o+=e; // https://bit.ly/3amh0v4