There were several tasks:
The first was to optimize the scene, because. Since we prefer the whole project to be assembled and rendered from a single scene, then all the interiors, simulations, sky states, atmospheres, etc. were collected in one file, which required quite a lot of work to organize the scene. Plus, what works for us does not always (almost never) work on render farms. So many materials, approaches, etc. were redone anew so that it worked not only for us.
The biggest challenge we set ourselves was to create rain and animated fountains. There was no request from the customer for rain, but I really wanted to depict a warm summer downpour, with the rays of the sun breaking through from the horizon. We downloaded the reference photos and went to work.
Because we love trying new things, or old things in new directions, we decided to make it rain with tyFlow. With a real breaking of drops on the surface, traces of them on surfaces, with ripples in the water from impact. A couple of days for experiments and the rain is ready. With fountains used phoenixFD.
We thought that it makes no sense to make unique jets and you can make one and copy it to all other places by shifting the start of each of them by a random number. It turned out quite lively.
Everything else was fairly linear and understandable. We coordinated the angles, agreed on the atmosphere, added details. Separately, we animated people with custom movements from the mixamo website, but we tried not to show them very close, so you won’t really notice people.