I am terrible at keeping secrets and I had to sit on a good one for the last month since GOW2 came out. Namely this one ... (Kotaku helpfully hosted the pic for everyone)
We were proud to get this into the game at the very last minute. I set a bad example though as I am always arguing for us to not add new stuff after Beta and I broke my own rule, bad programmer...
Its funny that the story could have actually gotten out a lot earlier if the journalists at the launch party had been paying attention. We were running around the Metreon Bar rebooting all the PS2's so it would look nicer on the Plasma TV's it was running on. I think the Journo's had been successfully distracted with the free alcohol.
Our marketing guys were nice and let us write a no bullshit little press release that is honestly a pretty fair reflection of why we hid it in instead of making it obvious. I tried to keep it relatively non technical and figured I would add a bit of extra detail on here.
So for what its worth:-
God of War 2 normally runs at 512 * 448, the 'HD Mode' runs at 640 * 448. Thats a 25% increase in Horizontal resolution. 640 * 448 is pretty much as high as you can run an NTSC Playstation 2 game. Gran Turismo 4 had a 1080i mode, but even that is a bit of a trick. If it wasn't running at 60fps, it wouldn't look any better than 480p. They switch between odd and even scan lines every other frame. We cannot sustain 60fps for the whole game, so it wasn't an option for us.
Our 'HD Mode' has to draw more pixels than the normal mode. This means that any place where we are 'fill rate' limited, the game will actually run a bit slower since it has to draw 25% more pixels. In places where the game is slowing down because its drawing a lot of particles or graphical effects, e.g. a big fight, it will slow down a bit worse in our 'HD Mode'. On balance though its probably only slower in a few places.
Now lots of games, us included, talk about 480p. In truth that doesn't actually mean we render 480 scanlines, we only do 448. This is because most televisions do not display all the scanlines. There is really no point in rendering them since no one will see them and you can use the processing time to do other things.
Its going to be the same on next-gen games. Everyone talks about 720p and 1080p, but in general a lot of games render a few scanlines less. This is also because the LCD and Plasma TV's don't render all 720 scanlines. Many more next gen games are fill rate limited, so you will see a lot of these tricks used to get that little extra bit of performance.
Its also true for the Playstation 2 and Euro TV's. In Europe the standard is 576P, but most people render only 512 scanlines. Unfortunately the 512 * 512 resolution that we render the PAL game already takes a lot more Video Ram than out normal 512 * 448 NTSC rez. To do the same HD Mode trick on the PAL PS2 would have needed 640 * 512 screens and there simply isn't enough VRAM (the 640*448 NTSC one only *just* fitted). Our SCEE Press team got a bit confused about why there is no HD Mode in the Euro release. But not enough VRAM is the real reason, its a bummer, wish we could have done it.
Alright enough resolution talk, I wanted to share a classic 'Internet expert' post that we found on the official Playstation boards after the release of the first God of War. It was printed out by one of the designers and put on the fridge at work where it caused a lot of amusement to all of us. Its kind of a geeky joke, but hey your reading a blog by a game programmer so what did you expect.
Re: God of War Demo Question
Progressive scan, from what I know (I may be wrong since I am talking about PC Progressive Scan), is when the disk basically reads ahead, alowwing the AI to anticipate your movement, allow the game 0 lag, and other features, as opposed to Tracking scan, which is basically scan only the location you are in, and nothing else.