Reduce the CPU usage when nothing is going on

[ntadej]

It seems Phoenix keeps doing high-FPS rendering even if nothing is going on (no animation, no user action). It might be useful to prevent this and only re-render when needed.

[EdwardMoyse]

Actually this is a good point - thanks @ntadej. Let me ping @9inpachi since I know he has been modifying the animation loop recently and might have an idea of how feasible this is to do...

[9inpachi]

Indeed. I also thought of implementing this after seeing a game that only renders when controls are used. We could have a similar render function only on either camera movement or when the animation runs. Let's keep this issue as a reminder of implementing this. Thanks @ntadej

[9inpachi]

See #233 for an attempt.

[EdwardMoyse]

This is interesting: https://discoverthreejs.com/book/first-steps/animation-loop/

(see render on demand)

[9inpachi]

(see render on demand)

We already have this in our ThreeManager. See this function. The hard part is to actually call it in tons of places and then manage every update.