THREE.clock.getElapsedTime has a side effect invalidating .getDelta()

[AndrewRayCode]

https://github.com/mrdoob/three.js/blob/master/src/core/Clock.js#L40

If the user's render function calls both getElapsedTime and getDelta in a requestAnimationFrame, the code will not work properly and it will be impossible to debug why without the "aha" moment of looking at the source. These two functions should not conflict with each other.

It's because getElapseTime calls getDelta, so for example if your code looks like this:

var elapsed = clock.getElapsedTime(),
    delta = clock.getDelta();

the delta will actually be the time between those two var statements!

A workaround for now is to call getDelta() first, which will get the delta between getDelta and the last getElapsedTime call, which is not ideal.

[mrdoob]

Uh oh!
Yeah... The design of Clock is dangerous...

[AndrewRayCode]

Relevant: http://stackoverflow.com/a/34934720/743464

[spbond]

In issue #11444 I also noted this problem, along with some others, and proposed some code which would completely decouple the two functions from each other. The changes I proposed are based on r85.

[Lowlet]

I just lost two days trying to play animation because of this. Thank god i found this thread. Can this be at least mentioned in the Clock docs?

[weilueluo]

Spent a solid hour debugging my program and finally found this... how is this an Enhancement not a Bug?

[manake]

This issue is opened since 2014 and this is still a bug.

Most importantly: The current clock doesn't allow to pause() and resume(), so it's entirely useless in some use cases and the only solution is to create a different clock class because sometimes no workaround is possible with current THREE.Clock.

[Mugen87]

At this point, please use the new Timer class if you experience issues with Clock.