With Sony retrofitting PS3s for 3D capabilities this June, more details have been released about exactly how the games will run in 3D. Since 3D requires two separate images, the console must now render another entire screen. Think about any game you've played recently that slowed down while the action got intense, then imagine your system now having to calculate that again!
3D also presents some new issues as far as graphical tweaks go. Screen tearing, which happens when the game outputs multiple frames while the screen, naturally, can only show one. If a game in 3D has a screen tear on one image, but not the other, the effect is multiplied. Another effect that needs to be done well is anti-aliasing, which is where the system smoothes out pixels to create a more natural look. Because you're viewing an image in 3D, any imperfection is now visible from two angles rather than seeming to blend in during normal motion.
Digital Foundry talked to Ian Bickerstaff and Simon Benson from SCEE's stereoscopic team about what they do to optimize games for the jump to 3D. They've got a few tricks up their sleeves to keep the new games running smoothly, though. "We have a simple three-step implementation process for making games in 3D," says Bickerstaff. "Step one is to create two images. The PS3 has two 1280x720 buffers, in a top/bottom arrangement, with a 30-pixel gap between them using for video timing purposes. It's the left eye image at the top and the right at the bottom."
They're also trying to keep games locked in at about 30 frames per second to maintain a smooth picture. For games like WipEout HD, which runs at 60 fps, this lets them easily adapt the game to 3D, because they can cut down on features while still keeping the game to a high standard. This can pose a problem though with games like MotorStorm: Pacific Rift because it's already running at 720p at 30fps. Luckily MotorStorm had a built-in solution. During the multiplayer, the game scaled down the graphics to keep the game out of a slideshow mode.
When 3D is released, comparing it to multiplayer versions of games is probably the most apt comparison. Because two screens are being rendered at the same time, the system takes much more strain, not to mention the extra options needed to keep a good-looking image. Of course, once games start to be made on a 3D engine, much of this will already be incorporated into the game. Since the technology is still very young (at least this incarnation) only time will tell how 3D fares in the games industry.
Source: Digital Foundry