verlet

https://gyazo.com/28f90f775ec43d6954cbd5d0710c7653

https://gyazo.com/dc9fe063094b9ee77f8efdd95cdbb883

https://gyazo.com/e2cfa99ccf9ec25c69e62c210edafd15

https://gyazo.com/9079c6797c1b0c9ca0bec58536cfbb33

蜘蛛の巣

https://gyazo.com/b3cb6d8ef6027d19c33ceec904c373f2