Technology dictates game design - Part 1

Posted by jimi on January 25th, 2009 filed in Uncategorized

I’ve been noticing over the last few years in particular that when a new technology comes out and makes a bunch of money for one game, every other game around crams the new tech into their game and hopes for the best.  Sometimes they get it right, but more often than not they are actually making their game worse.  In this series of posts I’m going to be looking at particular technology trends that have done this, and why it is detrimental to some of these games.

So to kick things off, I’m going to focus on physics.  This is probably the most obvious tech that has crept into games, and has become somewhat of a standard.  A lot of games do it right these days, but there’s another tech trend which is splitting the industry, and that’s nVidia’s Physx, which I’ll go into in a little while.

So physics is all around us in real life, and so it makes sense to try and emulate it in games.  It makes things seem more realistic, and also adds a large element of unpredictability to a game.  It’s this unpredictability that I feel is it’s main draw card, as it means each time you play through the game it’s going to be a little bit different.  The problem with this tech, and like so many others though, is that it is very noticeable when it’s not there, but just blends in when it is.

Now your average gamer doesn’t notice this.  The people who find out all their gaming information by walking into EB and looking on the wall aren’t interested in which game has got the most fluid physics engine, or which game has the most realistic looking Parallax mapping.  These gamers are looking for a bit of fun, and won’t notice these amazing technologies.  They will however notice when those technologies aren’t present, but they can’t put their finger on why.  This all comes down to a studio being able to make an immersive game versus a tech hungry game.

Why should we care about this demographic of gamers?  Because they are the ones spending a lot of money on console games, and really driving the retail industry.  Hardcore gamers generally know and understand at least some of the tech behind these games, and why they make the game better (or worse), but these retail gamers really don’t.  As time goes on a lot of these buzz words like ‘physics’ and ‘ragdoll’ and ‘normal mapping’ become selling points for the games, but once again, these retail gamers don’t know what they are, and so the developers seem to think that these technologies need to stand out like a sore thumb.

The first one that springs to mind for me is Half Life 2.  I love this game, and I really think Valve are one of the top developers in the world, but they are one of the earliest games that pulled off physics properly, and also had to put in gameplay mechanics that forced you to say “alright Valve I get it, you made a physics engine”.  By forcing the player to realise that certain barrels float, and by placing them under a particular ramp, you can create a path to the next section of the game.  Now this particular puzzle pops up after you’ve been screaming along a river in a fan boat.  You have to get out, make the ramp, then start up the boat again and launch over it.  This broke the flow of one of the best parts of the game I felt.  This is where tech begins to get in the way of gameplay.

I believe gameplay should come before the tech, and far too many games focus more on the tech and less on the gameplay.  Now HL2 was probably a bad example, it has fantastic gameplay and for the most part the physics was there to compliment the gameplay and immerse the player, but silly physics puzzles I felt broke the flow of the game slightly.  There are many games that do this far worse, but I think you get the general idea.

On the flip side, there are many games that are based entirely around physics that do it right.  One I found recently was “Crazy Machines“, basically a remake of the old “Incredible Machine” series from the nineties.  The games are based around the Rube Goldberg Machine concept, which is fun right from the start.  The Incredible Machine series used a predictable physics system, which meant that if you replayed a puzzle over and over the same series of actions would occur.  With Crazy Machines, the same is not true, and having a more realistic physics system leaves room for the same setup to produce different results.  This makes completing a puzzle an exercise in trial and error, mixed with a bit of luck.  Personally I think a predictable physics system is required for this type of game, and the ‘advancements’ in this field of technology have somewhat hindered the gameplay.  However the game still remains fun, and sometimes different results can unleash moments of hilarity.

So games incorporating physics engines can be good and bad, depending on their implementation.  A new technology is taking the bad to a new extreme, and it comes in the form of nVidia Physx.  To give you a brief overview, Physx was a physics engine brought out by Ageia.  Along side the physics engine they tried to usher in a new era of hardware, the physics card.  The idea was that now you would buy another piece of hardware, a physics card with a Physics Processing Unit(PPU).  This would free up your CPU for other tasks such as AI.  The uptake on this technology was very slow, and nVidia said right from the start that their GPU’s would be capable of the exact same thing, and they were already in half of the PC’s out there.  So when PPU’s didn’t take off, nVidia bought out Ageia, and ported the Physx engine to work on their 8000 series and higher graphics cards.

Now I will be the first to admit that the first things they brought out for this engine to utilise the different hardware were amazing.  A tech demo/game called Cell Factor was released which had hundreds of physics bodies smashing together, real time tearing cloth, the list goes on.  It was a technical marvel, but it wasn’t really that much fun.  This should have been an early warning that this technology was doomed from the start.

Jump forward a year or two, and nVidia has done it’s best to get developers on board to use the Physx technology in conjunction with their graphics cards.  The problem with this is that not everyone has these graphics cards.  To be able to merge this technology seemlessly with gameplay, it has to be a standard across all machines that will play the game and not a variable.  

Early adopters of the technology didn’t do a very good job of integrating the technology, and Ghost Recon Advanced Warfighters is a prime example of this.  In it’s multiplayer mode, there’s always the possibility of players having/not having Physx capabilities.  Now most of the additions to the game are basic things like improved explosion effects and don’t actually impact the gameplay.  There are however a few extras that stick out in multiplayer games, such as cars exploding.  With Physx hardware a car will actually move if an explosion happens nearby, but without Physx hardware the car will remain static.  The way they handle this in a multiplayer game is based on where the nearest person without Physx is.  If someone without Physx is nearby, even the player with Physx will see the car remain static, however if the player without Physx moves away, the car will move, and the settled position of the car will be updated on this players game when they move back to this position.  This will break the immersion of players with the technology, as it makes the world inconsistant.

The other main point to consider is how much of the GPU’s power is committed to Physx calculations, and how will this impact on the game’s graphical performance?  Lower end 8000 series cards may have a significant impact on performance, and while the game’s physics will be more immersive, will it drop the framerate to a point of unplayable?  I am currently waiting for a copy of Mirror’s Edge, a new game that sports the nVidia Physx branding, and I will update once I have played through and seen the difference not only in immersion but in performance.  FYI, I’m running an 8800 GTS 640.

So I think that about wraps up this topic.  So to recap:

  • Physics are good when they immerse a player into a game world
  • Physics are bad when they stick out like a sore thumb
  • Physics hardware creates problems for developers as they are a variable factor
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