The "optimal" plant layout flooded on its own ground — GPU flood simulation, OpenUSD and Omniverse Kit in a generative-design loop
In short A generative-design (GA) tool picked a water-treatment-plant layout 6.3 % cheaper than the current plan. It got there by cutting the whole plant into a basin 1.3–3.4 m below original ground. Its flood map could not see that, because the map was run over the original ground. I re-ran rain and inflow over the ground each layout creates with a 2D shallow-water solver in NVIDIA Warp (GPU, 4.7 s per plan). The optimum flooded at 3 facilities, and after repair it lost its lead. The result agreed with HEC-RAS 2D (flooded-area IoU 0.94, danger verdicts 14/14). OpenUSD is the source of truth: the plans are variants of one file and the design numbers are attributes (150 checked, 0 mismatches). Review happens in Omniverse Kit. Four AI surrogates were tested; none was safe enough to judge, so AI only suggests evaluation order. Site, terrain and unit costs are synthetic or assumed; no real client or site data. What it looks like in Omniverse This is the GA's optimum, plan C, in ...