Digital Foundry vs. PlayStation Move

It's been less than 24 hours since I attended the PlayStation Move reveal event at GDC, and I'm gathered in a small conference room of game-makers and press for Sony's presentation to developers. I'm looking for answers. Yesterday's event established release date, ballpark pricing and bundling options. I got to play a bunch of games too, but many of them were so early in development that accurately gauging the potential of the controller was a tough call.

The state of much of the software was such that you could be forgiven for thinking Move is little more than a Wii MotionPlus with some fancy camera options. But I know how good Sony's R&D teams are, I've read up on the underlying tech, and with the right concept and execution this should stand alongside the technological innovation found in Project Natal and in terms of certain, crucial applications, it could indeed surpass it.

As for the nuts and bolts of the wand itself, SCEE's David Coombes sets out his stall.

"The controller itself has a bunch of inertial sensors built into it which can be used to detect motion. There's an accelerometer, a gyroscope and a magnetometer in there. Those can be used to determine position and orientation," he says. "However, inertia sensors have some inherent limitations. They tend to suffer from drift and inaccuracy, there's a lot of noise in the data.

"Some of that is because these are simple integrated circuits. These aren't the sensors you'll get in an aeroplane for instance. What we did was add a glowing sphere that the [PlayStation Eye] camera can track, similar to the tech used in motion capture labs."

The combination of internal sensors - talking to the PS3 via a Bluetooth connection - and the PSEye tracking the glowing, bulbous tip of the Move adds to the flexibility and accuracy of the controller.

"The really cool thing about having the illuminated ball is that it works in all kinds of lighting conditions," Coombes continues. "It can work in darkness because it is self-illuminating. You change the colour of the ball and when you have four players, each one can have a differently coloured controller.

"The controllers can change colour too. So they can turn red as you move into a dangerous area, for example, or it can flash when you fire a gun. So as well as the tracking there are some interesting game design options you can use within the controller."

Sony research and development guru Anton Mikhailov takes point on much of the technical data imparted at the briefing. Straight away he's talking about the "dreaded lag". Yesterday, at the main event, latency with Move was defined as being under one frame - a state of affairs that seems almost unbelievable, putting the motion controller on equal footing with the DualShock 3 and Sixaxis. It turns out that getting the lowest possible latency was one of the team's primary objectives.

"The interface itself has some inherent latency because there's processing and so forth," explains Mikhailov. "But also, the player might have latency. If I want to throw a punch, I'm gonna move slower than I would if I were just pressing a button, so it's a two-part thing.

"What people often forget is that latency actually is very important for casual games. People think you can swing around, you can do some gestures and that's OK. Actually for a game to be connected to the player, to feel intuitive, it has to have low latency. Latency creates the barrier between the user and the interface."

Mikhailov then goes into an in-depth briefing on just about all the various PlayStation controllers Sony has been responsible for, from the DualShock to the SingStar mics to EyeToy and Buzz. The latter devices all have limited functionality but they are intuitive and familiar to the casual audience. What Move - and by implication the WiiMote - does is to give the flexibility of the DualShock without the abstraction. No longer do you press X to perform a motion like, say, swinging a bat. You simply use the wand to mimic the action.

"It's like a bridge between casual devices and the DualShock," Mikhailov adds. "Some games are still going to be better on the DualShock. We're not trying to take games away from the DualShock in any way. There are some times when you really need buttons and analogue sticks."

According to Mikhailov, it's all about being intuitive, robust, and being able to work in all conditions.

"One big issue with EyeToy we always tried to tackle was lighting. If you have low-light conditions, you can't see the user and you can't track him very well. That's why the spheres are illuminated: you can work in pitch-black conditions. Second thing: it's robust. It goes back to precision: if the interface isn't precise, the user starts to blame the interface and we don't want that.

"It's also intuitive. It won't lose track of you, even if the camera loses track of the sphere it'll compensate with the accelerometers. I can put the controllers behind my back, I can swing backwards, it's not losing tracking. You don't have to worry about it freaking out... there's a one-to-one connection."

Based on yesterday's presentation and gameplay session, if there was one positive you could take away from the event, it was that Move is clearly a far more precise implementation than the Wiimote. Some of the games felt clearly more "tactile" than the Wii equivalents.

Move also takes care of the basics. When I spoke with Kudo Tsunoda at gamescom last year, I was surprised that you couldn't point with Project Natal. As Anton Mikhailov powers up one of his myriad tech demos, it's clear that Move does pretty much everything a developer or gamer could want from it. Armed with twin wands, he's pointing as you would with a light gun or laser pen.

"Doing a pointer is very easy because you have a 3D object in space," Mikhailov says. "All you do is shoot a ray from where you are to the TV. From a programming perspective your math is very simple, it's like a ray-tracer."

The demo simply shows Atari VCS style rectangular blobs moving around the screen as Mikhailov wields the twin controllers. It's clear to see that while pointing works, the targets are jittering. But this is by design.

"You can see the jitter, but the jitter's in my hand," Mikhailov explains. "I have a tripod here. Check this out. If I stabilise myself on the tripod, I can get rid of the jitter. It's in my hand. It's not system jitter. It's not some kind of noise. If you want to make a really accurate shooting game, you keep the jitter in because you want the players to get better at shooting.

"If you want to make a more casual game, you smooth this out. It introduces latency when you smooth things but for a casual user, maybe that's a better thing. As a developer, you have control of this. If you want to make a hardcore game with precise tracking or if you want to make a more casual game, or give some help to the user you can do that."