Hi! I can't answer any of Adam's questions about Dead Rising, but I did want to chime in belatedly about next gen crowd densities, as I kept intending to do since Greg earlier post. It is hard to do apples to apples comparisons of crowd simulations, as Adam suggests there is such a range of complexity for the crowd members. How smart are the agents? How detailed are their geometrical representations? What kind of animation is used?

Over the last year I have been looking into high performance crowd/flock simulation on the PS3's Cell architecture. (I work at SCE's US R&D group.) Since I wanted to push on the crowd size parameter, I use a very simple visual model for the individuals in my simulated crowds. Their brain are just some steering behaviors. Keeping that in mind: I am able to run a "boid" simulation of a school with 7000 fish animated at 60fps. My preliminary 2d crowd model runs 10,000 individuals at 60fps. In both cases the behavioral update rate is 1/8 of the frame rate. The fish "bodies" are about 30 polys with some displacement animation in a vertex program.

The general idea is to update the simulation in parallel (on 6 SPEs) using the same spatial hashing used to accelerate proximity queries. For those who want the gory details, I will be talking about this "PSCrowd" system at GDC: http://www.cmpevents.com/GD06/a.asp?option=C&V=11&SessID=2769

Our plan is to show these demos and one with more interesting graphics as part of Phil Harrison's Keynote: http://www.gdconf.com/conference/keynotes.htm#phil