@felixmariotto If @lai calls Clock.start(), elapsedTime will be set to 0 which probably breaks her animation.
Unfortunately, the Clock class has some conceptual issues (e.g. https://github.com/mrdoob/three.js/issues/5696) and should be replaced with something new. Some time ago, I’ve submitted a PR that introduces a new Timer class. You could use the code in your project and then just call timer.reset(), if you resume your animation. The method might be renamed in the future since it does not perform a real reset operation of all timer values. However, it should do what you are looking for.
The PR also updates an example that shows how the replacement of Clock with this new class looks like.