HANDS ON GUIDE

02 - Gameplay Physics

The aforementioned topic of exploding walls lead us neatly into Gameplay Physics, as being able to destroy a wall radically changes the way in which you can play a game. If you can destroy walls, then you are no longer restricted to walking along pre-defined corridors – just blast your way through and you can traverse the level however you want.

One of the big improvements that PhysX brings is giving fluids weight and force. Water can gush and flow as it should, spilling over objects and pushing them with a realistic force.

Now imagine the first mission of Call of Duty 4 with such fluid – when trying to escape the sinking ship you’d be buffeted with gushes of realistically modelled water, pushing you off course in a more believable and engaging way than the game currently manages. We should point out that this is purely a hypothetical example – Call of Duty 4 doesn’t use PhysX and there are no plans that we know of to implement it.

Gameplay Physics also allows fragments from explosions to deal damage, just as they would in real life. Without physical modelling of fragments, they are purely graphical and have no weight or force – if you were damaged from an explosion it was purely because you were standing within a damage-dealing zone that was arbitrarily applied to emulate the effect of being struck by debris. With a physics processor, you could dodge the planks and shards of metal and avoid being hurt.

The downside to Gameplay Physics should be obvious by now: as it affects the way that a game runs, that game will require a physics processor, else it’ll either refuse to run or will run very slowly as your CPU struggles to calculate the extra physics work.

Conversely, Effects Physics doesn’t fundamentally change how a game plays, it just makes the game look prettier, so a physics processor isn’t required. Effects Physics could be left as an option to enable or disable in the options screen, but with Gameplay Physics, the situation isn't quite so simple. Convincing game developers to create a title that requires a non-standard hardware feature may be tricky. However, now PhysX is supported on GeForce GPUs (8-series and above), there is already a greater installed base than Aegia ever had with its discrete PhysX cards.

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