nl_tokens: Recursively collects octants that lie inside the specified region .
pl_tokens: function cull ( octant , region , result ) { const children = octant . children ; let i , l ; b . min = octant . min ; b . max = octant . max ; if ( region . intersectsBox ( b ) ) { if ( children !== null ) { for ( i = 0 , l = children . length ; i < l ; ++ i ) { cull ( <mask> [ i ] , region , result ) ; } } else { result . push ( octant ) ; } } }