Nvidia’s solution doesn’t work with large game areas. Even for a relatively small area it eats ram like you wouldn’t believe. Besides, this is just a less advanced version of what Epic already tried (hey they already did cascaded voxel level of detail!) and concluded it wasn’t really fast and flexible enough to bring in, especially not with the Xbox One.
Now Voxel Cone Tracing is a really great idea, and I’ve actually been working on… well getting them to work myself along with many others. Maybe soon it will be practicable, but it’s not right now and Epic tried quite hard to get it so.
Edit- Imperfect shadow maps are awful. Super light leaky, SUPER high performance hit, depending on how you sample it gets super “poppy” with lights and/or shadows popping in and out.