Dr. Who And The Sleeping Weather

Cheeky little timely reference in the MR's title to the brits among us - but if you don't actually know anything about her adventures, the Weeping Angels are monsters that decide to move only when nobody's looking at them. What if the opposite principle was applied - that weather only moved when you laid eyes upon it?

Due to having SOME hooks in the existing thinker system, it won't run double-speed in splitscreen - but having a lot offloaded from it reduces the weather-related burden during P_RunThinkers by about 50%, according to profiling done by Sryder. The only possible downside is that if you start dropping frames, the rain slows its descent. Under normal gameplay circumstances this should not happen, but it's something to be aware of.

It's already paid major dividends in performance for kart, so I figured y'alls upstream deserved to give it a look over too.