Archive for the 'XNA' Category

Back From The Dead

A while back, I posted about a physics engine/video game I was putting together. Over the past year, work and school have limited my ability to make any real progress on the game, but I’m ready to jump back into things. 

Microsoft recently announced an initiative to allow for Community games to be published on Xbox Live, and I’d love to put something on there. Who knows – I might never get to that point, but that goal will make me focus on creating a cohesive (and feasible) game.

I’ll be posting updates, so stay tuned.

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XNA Boss Comments on Zune Progress

In a recent interview with Eurogamer, Chris Satchell, head of the XNA platform at Microsoft, commented on the progress of Zune as a gaming device (it’s going well).

“That touchpad is great,” said Satchell, who demonstrated a basic Zune shoot-’em-up called Zauri at GDC in February. “I’m used to mobile games and it’s always terrible. Not the games, but the input. And so this sort of blew me away.”

I’ve been curious about Microsoft’s handheld gaming plans for the past couple of years.  Since the original Xbox launched in 2001, rumors have consistently popped up hinting that Microsoft was planning on giving Nintendo’s DS and Sony’s PSP some competition.  Those rumors have yet to materialize, and with Microsoft’s new focus on Zune as a gaming platform, I’d bet that any plans for a more traditional handheld have been shelved for the time being.  And that’s the right call.

Nintendo has taken the world by storm with DS – they’ve seemingly captured the Game Boy’s audience while enticing new gamers of all kinds (most notably women).  And they’ve done it by positioning DS as a games first handheld. 

That leaves an opening for Microsoft to make some headway with Zune as a more media centric product (where they’d be competing with things like cell phones).  Sony tried to take a similar angle with the PSP, but their marketing has been confusing – they’ve positioned PSP as both a games device and a media device, but the software library was initially lacking and its media functions are basic at best.  Ultimately, PSP’s mindshare is muddled among consumers, as no one knows exactly what to make of it.

The Zune brand has made some great strides in the market since the release of Zune 2 last November, and an added emphasis on gaming could really give it some differentiation compared to Apple’s iPod. Of course, iPod already has gaming capabilities, but with their XNA initiative, Microsoft could really make some noise with community created games.  It looks like that’s the avenue they’re taking, and I think it’s going to really pay off for them.

Realism and Physics in Video Games or: How I Learned to Love the Rope

Over the summer, I began work on a video game/tech demo using XNA Games Studio Express.  My goal is to create a Bionic Commando-inspired 3D grappling game, but more on my game concept in a future post.

Since grappling (that’s swinging around like Tarzan with a grappling hook) is a key component of my game, I spent much of my initial development time working on a good rope physics solution. 

My first instinct was to make the rope act as realistically as possible.  It seemed logical to assume that a realistically swinging rope (that accounted for initial velocity, gravity, conservation of momentum, etc) would add depth to my gameplay.  After getting my initial rope physics implemented, though, I was surprised by the results.

Rope Realistic

Swinging from grapple point to grapple point felt pretty good as long as the object was moving directly downward (or not moving at all) when a “grapple” was initiated.  However, as you can see in the diagram, if the swinging object had any velocity in the X (horizontal) direction towards the grapple point at the start of a grapple, my rope simulation didn’t act as I had anticipated.  Instead of a nice, circular swing, the object would continue on its path towards the grapple point.  Only after the object had passed the grapple point and reached a point along the swing’s circumference would the rope exert force on the object, at which time the object would be sharply pulled in the opposite direction. 

I quickly realized that a perfectly realistic rope simulation wasn’t going to result in optimal gameplay.  Maintaining forward momentum was difficult, and grappling was more a chore than a pleasure.

Rope Better

To make things more fluid, I decided to try something different – at the start of each grapple, I transferred any horizontal velocity into velocity pointing along the tangent of the optimal swing’s arc.  The idea was to maintain a sense of constant momentum while allowing for a more circular arc in the swing.  I immediately noticed an improvement – this method felt far more natural than the perfectly realistic model, and because maintaining forward momentum was a breeze, it was much easier to travel across long distances.

Working on this problem made me realize that one of the fundamental elements of quality game design is finding the right balance between reality and, um, fun-ality.  Understand that I’m not talking about art style or color choice or even types of game content when I refer to reality.  When I say reality, I’m talking about what the user anticipates will happen when they perform an action.  When a human player initiates an onscreen action in a game (via a button press, an arm motion, etc.), he expects a certain thing to happen in that game’s world. 

He can’t help it.  

We live in a world with inherent physical rules and properties, and we’ve spent our entire lives learning the rules of cause and effect.  We can’t help but transfer our notions of how things work in the real world into expectations of how things should work in a game’s world, and it’s this connection between the anticipated result and actual result that dictates our emotional and intellectual response to a game’s design.  If a game is too similar to the real world, it’s boring.  But if it’s too fanciful or too off the wall, it’s confusing and frustrating.  The best games are the ones that conform to our expectations to a point but also offer something unique that builds on or enhances our real-world perceptions of reality.