Some more information on the Talokanil water bombs:
Can you tell us more about the water bombs?
The hydro bombs were conceptualized by Hannah Beachler and loosely based off a hand grenade. From here we took some liberties saying that inside our obsidian container were millions of hydrogen molecules. Once the obsidian breaks these hydrogen molecules attract millions of oxygen molecules and create a massive water event. These hydrobombs were the catalysts for the street and city flooding. An average hydrobomb explosion was around 70ft high and generated 200,000 gallons of water. To achieve this, ILM built a complex chain of dependencies in a proprietary suite of robust and efficient solvers for both liquid and air simulations to generate the surface water, whitewater, spray and mist components of the hydrobombs. The components then were rasterized into dense frustrum grids to help blend surface and volumetric elements. Large dump tanks were integrated into the sets, which generated safe onset flood water and character interaction. Additionally, real world reference was used as a guide for increasing the amount of water and turbulence levels, to enhance the danger of what was shot on set. The flooding water needed to cover very large regions of the city. To do it in a single simulation would be very time intensive, so a clustering approach was used to break larger areas into smaller zones and iterate on each individually. We defined large overlapping bounding regions between these clusters with aovs and were able to blend seamlessly between them in comp.