Arach Tchoupani

For a game you've got to be better than realtime. Now, I do know a thing or two about writing games professionally, though not really high end stuff. If I've got a physics engine pegging the CPU to 100% then I can't do anything useful with the game. Even if I can dedicate one core to physics it's still going to cost me in terms of RAM and disk usage and software complexity, and even then I've got to make sure the physics completes fast enough that the rest of the game isn't waiting on it. Cores aren't completely free. I've yet to even see a physics engine for a game that can handle a large body of water (tens or hundreds of millions of particles) with lots of movement and reacts to external forces such as character movement that can run silently and quickly on a single core. Good physics is expensive, which is why you don't see it in games on a large scale such as for water.

Now, we also want to do things like run AI on a separate CPU core if possible, so it can be more complex than if run on the primary core. Do we want really awesome water and sand or better AI? AI wins out every time. Physics like in the demo video are also at the tail end of what people care about. It's more important to handle large objects properly, so if a jeep runs over a bomb it's going to react appropriately. No one cares if the dirt on the road is a pre-programmed animation or if it doesn't do anything at all because it's just a texture. Those small details will be great eventually because they'll add to the game world's realism, but they just aren't worth their cost on current CPUs

Context for the previous posts about the physics engine.