Thursday, May 28, 2009

The Next Generation of Neural Networks

Been putting this video off for a while due to study commitments, but I finally managed to sit down and go through Geoffrey Hinton's talk on neural nets. Ironically I'm deep down an assignment for this Friday so go figure ...

I like this guy. Doing my postgrad back in the mid 90's on AI, neural nets and back propagation were all the rage; in fact I used one as my major project in a model of the hippocampus. Even back then there were hints of limitations to back propagation, but no-one anywhere was this blunt.

On first inspection of the new model (~6:30 in), there seems to be 2 problems with the simplification of the network:
1) The middle layer of a neural network allowed non-linear relationships. As a feature detector in graphics there may not be much need for non-linear relationships, but most simulations would need them.
2) Without inhibitive links between the feature nodes there is nothing stopping a feature being picked up by more than one node. If you had a very large part of the image that really was one feature, most of the nodes would be trained toward that an miss the finer outlying features that it would be forced to find with hidden layer inhibitors.

Ok, so after the simplistic model is dispensed with (~14:30), multiple layers are back to give the non-linear transformations. Scrap problem 1. In fact by the time he re-adds back propagation (~30:00) there's 8 layers to abstract through. Or is that 4 then a rewind through the original 4 using back-propagation? Yep, w4t on the layer above the 30 node layer would be w4 after time.

Wow, the jokes are getting funnier. ".. and it would be nice to know what other companies are in this Enron cluster" (~33:45).

Finally (~45:00) inhibitory weights return, but with the provision that they are only used at the lower layer once it has been trained from the step before. He must be purely relying on the random weight distribution to map different features?

Overall very interesting talk and a good refresher on what's happening with neural networks.

Monday, May 25, 2009

GameLog 93 & 94

Mount & Blade (58h) - Played through a fair bit of the main campaign, but Greig's description of "The Eagle and the Wolves" mod had me chomping at the bit to create my own kingdom. Started an AAR for the journey called Tales of Ymira. Need to get back to the story though, I'm almost 2 months ahead. Had an interesting idea to take screenshots and run them through GIMP to get a pencil-drawn look. Ymira is going to be the historian and artist of our clan.

Trackmania Nations Forever (10h) - Cameron now has over 40 tracks created between both computers. I've been roped into testing the and offering some encouragement and guidance, along with racing a fair bit on the Real F1 Racing server.

Elven Legacy (5h) - Ben picked up on a couple of things I'd missed in this game, so I fired it up again to push through the bonus missions that had held me up.

Team Fortress (3h) - Test of the new spy and sniper patches.

World of Goo (2h) - Picked my way through to the end of level 3 to get more goo balls for the tower. Been working on a tower design on paper that combines all the single-strand joiners into on middle spoke so that you can take it out and release all the non-double-linked goobers. Didn't get too high on the practical implementation though.

World Series of Poker (1h) - Another championship round done. Keeps crashing.

Osmos (1h) - Demo for an interesting game offf GWJ

Sunday, May 24, 2009

Earth Rising

We had gathered out at dad's farm house, the remotest location we knew. The night's festivities were over but some were still over at the fire talking between themselves. They won't be long, the Bundy's run out.

"What the .."
Following his gaze to the horizon I, too, saw an odd sight. Rising over the mountains appeared to be the moon, but coloured blue with wisps of white banding it. Bigger too than normal. It looked like it had a moon of its own, brilliant white peeking around from behind the bottom half. Then I saw it; the unmistakable shape of Australia sitting in the southern hemisphere. Shrouded in darkness. The pattern of other continents projected through the wisps to confirm the image: Earth.

The 4 of us at the back steps stood in awe as the vision rose higher and higher into the sky. Slow at first, but accelerating past the zenith and over to the other horizon. We followed it to the front of the house where gasps and the drop in conversation indicated the progress of the sight through the party. Questions started in hushed tones, and as it slowed and settled close to the horizon the theories sprang up, louder and louder until those present were engulfed in debate. Deep down I knew. This was a sign of the end. Not what I'd expected, but ominous none the less.

The vision shimmered. On the horizon a glow like the new dawn appeared, coming up and over the projected earth. Clouds reflected the glow to surround the Earth like a nebula. I looked deeply into the clouds, looking for a mushroom shape. Not there. Yet. The clouds warped with a blossoming wind, expanding to blanket the northern sky. Earth shimmered again, then faded back into the cloud. Little spots of red remained as the only indicator of where it was. They multiplied. No, not an earth shape anymore, a top of a rising mushroom cloud. More appeared, 3 in the heart of the scene. Haze cradling the explosions cleared to reveal reality.

Then the screaming started.

I ran with my 2IC back to see the horizon south. Far in the distance more glows were visible. Down the valley a sweeping fire had erupted. Might be a cause for concern, but if that's all we have to deal with we're going Ok. 2 tomcat missiles flew low overhead on their way south. Conventional weapons? Someone, somewhere is throwing all they have.

Monday, May 18, 2009

Procedurally generated city

Procedurally generaated city screensaver from Shamus Young:

Thursday, May 14, 2009

GameLog 86 -> 92

With all the Uni stuff I haven't been feeling the urge to write up the game logs, so unfortunately 6 weeks have gone by. It hasn't stopped me from playing games though ...

Elven Legacy (35h) - Lots of time on the demo, then found it for only $30 on steam.

Colonization (20h) - Couple more games.

Civilization (15h) - New tectonics map mode is wonderful with advanced start, duel map and 3v3.

Trackmania Nations Forever (15h) - Playing lots with Cameron as well as finishing up the Competitive Computer Games summer league. Cameron is taking a shine to creating all sorts of tracks, in fact all sorts of games that allow you to create things (like spore). The tracks are great. I wouldn't have thought he could have made the tracks with differing heights and placement of pieces, but he's now telling mommy where all the pieces are ..

Kongregate (10h) - Procrastination king (just one more achievement)

Baldur's Gate (10h) - Playing through the original series with Ben. Probably another 5 hours trying to get the stupid thing to connect.

Free Realms (6h) - Chase Windshield - level 4 card master

Mount & Blade (5h) - Birthday present from Greig.

World Series of Poker (4h) - Scott & Corina installed it and I ran a tourney or 2. Keeps crashing.

Neverwinter Nights 2 (2h) - more time trying to set up multiplayer. Coming back to this once BG and BGII are completed.

Skate 2 (1h) - Procrastination time.

Tuesday, May 12, 2009

Tecra A10 blank screen on boot

The new laptops have a 'feature' that they automatically detect a connected monitor and send the signal to that on startup rather than to the laptop's monitor. In our situation we have the projectors hooked up to the laptops constantly, but the majority of the time (and especially on boot) the teachers are using the laptops as a laptop, not through the projector.

Finally found a way to turn this 'feature' off:

Access BIOS
1. Turn on computer by holding down power button while pressing the ESC key. The machine will beep, then display: Check System, then press F1
2. Release ESC key
3. Press F1 key

4. Go to the second page by pressing PageDown
5. In the Display setting, set to LCD+RGB instead of auto-select.
6 Press End to save and exit

Wednesday, May 06, 2009

The player is the star

Another part of Soren's article on Sid's Tips focused on leaving the fun to the player:
Creating story-based games can be an intoxicating experience for designers, many of whom go overboard with turgid back stories full of proper nouns, rarely-used consonants, and apostrophes. Furthermore, games based on complex, detailed simulations can be especially opaque if the mysterious inner workings of the algorithmic model remain hidden from view. As Sid liked to say, with these games, either the designer or the computer was the one having the fun, not the player.
To me this is why Masters of orion 3 failed; the fun was taken out of the hands of the player. Somewhere in the process of reducing the micromanagement of an empire into an emperor's influence, the game lost the fun as well. Once the point limit was removed to allow micromanagement again it still didn't bring the fun back. The golden egg was broken.

In my quest to build totally dynamic virtual worlds that could exist quite happily on their own, I hope I'm not taking the fun out and giving it to the developers of the worlds. The project should lead to living, breathing worlds as a shell for the real game, but the real games are still only imaginary. This point of Sid's raises doubts that I may not be able to validate until a game uses the procedural world that is generated.

Game design for education

Although possibly not meaning it, Soren Johnson recently pointed out an interesting fact about educational games while explaining Sid Meier's 5 rules of game design:
Games still have great potential to educate, just not in the ways that many educators expect. While designers should still be careful not to include anything factually incorrect, the value of an interactive experience is the interplay of simple concepts, not the inclusion of numerous facts and figures. Many remember that the world’s earliest civilizations sprang up along river valleys - the Nile, the Tigris/Euphrates, the Indus - but nothing gets that concept across as effectively as a few simple rules in Civilization governing which tiles produce the most food during the early stages of agriculture.

I see this all the time in educational games. The focus is on the content, not the game or the game mechanics. A great educational game should be an experience you enjoyed, but you walk away with knowledge and understanding. The content is secondary to the experience, but interacting with the experience rewards embedding the content.

I've been a big fan of incidental learning and believe that to be the key to the success of games like Mathletics.