This has got to be one of the more insane physics demos I’ve seen so far. Most physics engine handles the basic rigid bodies and such, but start to fall apart with more complex interactions (i.e. fluid and cloth simulations). With the demo shown above, from Nvidia, it seems these difficult problems have been solved. Cloth, fluid, smoke, and rigid or soft bodies, all interacting with each other? It looks great. The author, Mike Macklin, has even posted a pre-release of the SIGGRAPH paper explaining the technique here. I took a quick look, and I will be giving it some serious investigation soon. These types of complex physics interactions are exactly what I am trying to do myself. Hopefully the implementation will not be that difficult, but I have a feeling I have a long road ahead of me. Wish me luck!