Untapped possiblities: The Wii

[Goofonian]

I'm still waiting for that adventure game renaissance.

Go buy zack and wiki. If that games sells enough, publishers will realise there is a market for intelligent adventure games that make good use of the wii's capabilities. Then maybe, just maybe, we will get our renaissance. If it doesn't sell it will be used as board room data to show why not to bother making adventure games.


As far as how the wiimote works, it just has three accelerometers. Go back and watch some of the videos from when people were connecting the wiimote to PC's over bluetooth and you'll get an idea for how it works. The accelerometers tell the wii when the remote is moved and in which direction relative to the remote. When the remote is stationary (or close) gravity produces a constant acceleration downwards allowing the wii to determine its exact orientation by the ratio of the accelerations in the x y and z directions, it doesn't need any sort of calibration at all. As such the wii is capable of complete 3D motion sensing, the problem is that to implement a program in the wii that was capable of determining the exact positioning and orientation of the wii at any time (as well as its movement) for something like, say, true 1:1 lightsaber control would require some really fancy algorithms. Unfortunately it seems that until someone puts some serious effort in and produces a motion sensing middleware package for this sort of stuff, we are just gonna get lazy efforts at motion where movements in a particular direction just replace a button press.

 

[Arbre]

The SIXAXIS can detect tilt and acceleration but it doesn't work as a pointing device. In addition to tilt and acceleration, the Wiimote detects the location of the sensor bar to do the pointing. The two controllers are not directly equivalent. Wiimote = SIXAXIS + pointing. The SIXAXIS motion sensing is equivalent to the nunchuck by itself.

Don't get me wrong, but from the moment you can detect rotation, it means you can know the orientation of a device, and from the moment you can gauge acceleration, it means you can know the latest position of same device.
With all this, you could exactly make a pointer. You just need to strap a laser on it.

 

[Nordstrom]

The SIXAXIS can detect tilt and acceleration but it doesn't work as a pointing device. In addition to tilt and acceleration, the Wiimote detects the location of the sensor bar to do the pointing. The two controllers are not directly equivalent. Wiimote = SIXAXIS + pointing. The SIXAXIS motion sensing is equivalent to the nunchuck by itself.

Don't get me wrong, but from the moment you can detect rotation, it means you can know the orientation of a device, and from the moment you can gauge acceleration, it means you can know the latest position of same device.
With all this, you could exactly make a pointer. You just need to strap a laser on it.

Check out this page [http://graphics.cs.ucdavis.edu/~okreylos/ResDev/Wiimote/index.html].

In theory, accelerometers can be used to measure position but with real-life implementations it doesn't work. It's a difficult technical problem.

1. To accurately measure position, you need perfect measurement accuracy. That isn't going to happen for surface-mount accelerometers that go into a $50 product. One web source says they only cost Nintendo 50 cents each. I don't know if that's correct but it sounds about right.

2. Accelerometers can't tell the difference between acceleration due to gravity and acceleration due to moving your hand. Yes, there are algorithms that have been developed to estimate and subtract off the influence of gravity but these algorithms are also subject to error.

3. Tilt is estimated by looking at how the acceleration due to gravity changes with the rotation of the device. However, this information is also mixed in with hand motions. In effect, they are trying to estimate 6 axis' of motion (3 translations, x,y,z, and 3 corresponding rotations). However, they only have 3 sensors. To measure all of the directions accurately, they need to add three gyroscopes. The Wiimote doesn't have gyroscopes because they cost too much. (For math buffs: this is like trying to solve an equation that has 6 variables while only knowing 3 of them.)

4. Accelerometers don't measure position. They measure the change in the change in position. Said another way, accelerometers measure the change in velocity. Converting from acceleration to velocity to position is such that small measurement errors lead to larger errors in the estimation of position. This is called drift. You could be holding the wiimote perfectly still but the wii will be seeing your hand slowly moving upwards. Subtracting off this drift means that the position is no longer known. (For math and physics buffs: errors in the estimation of the acceleration due to gravity of 0.1% (i.e. 1/1000g) over 5 seconds would lead to a positional error of half a foot. Converting from acceleration to position involves two integrations.)

5. Detecting the small tilts required to aim a pointer require
- measuring changes in acceleration due to gravity as the device rotates.
- the hand not to be moving in other ways
- knowledge of how the wiimote is positioned relative to the TV.
This is why there is a sensor bar. There's a CCD (i.e. video camera) in the front of the Wiimote that sees the sensor bar and figures out where the Wiimote is pointing.

(Okay, I went overboard but it's an area of my expertise and I got excited.)

In short, I'm really impressed with how well Nintendo has implemented the wiimote but there are limitations due to the nature of the technology. The CCD is used when you're aiming. The accelerometers are used to detect larger motions like swings, tugs, and tilts.

I'll give it a rest now.

Karl

 

[Arbre]

Don't get me wrong, but from the moment you can detect rotation, it means you can know the orientation of a device, and from the moment you can gauge acceleration, it means you can know the latest position of same device.
With all this, you could exactly make a pointer. You just need to strap a laser on it.

You're assuming the device never moves when it's powered down.
This is the beauty of the sensor bar for the Wii. Pointing the Wiimote at the screen to activate a game or channel ensures that the main unit can determine the position and orientation after power-up. From there, yes, the accelerometers are sufficent to continue tracking.

Indeed, I missed that part. Duh. If you switch the console on, with the controller being, well, in some absurd position, this same stupid position will be the by default position which every move will be based on.
So no pointer.

Thanks for the explanation, Nord'.

What about the topic at hand?

 

[Nordstrom]

I'm hoping that someone comes up with something revolutionary but I'm not sure whether it will happen or not. People seem to like Metroid Prime 3 but I don't hear anyone saying that the control scheme is so good that they wouldn't play anything else.

I think that the Wiimote is (at best) half way between an evolution and a revolution. It's better for some things but it won't transform everything. For example, I like racing games and I love the idea of steering with a steering wheel but, from what I've heard, the wiimote steering is more sloppy than an analog stick. Most of the successful games on the Wii are almost identical to their prior incarnations (Metroid, Zelda, Mario) but with a control scheme that is slightly more intuitive.

I think that it will come down to funding the types of gameplay that are ideally suited to the Wiimote. As cool as dual-wielding crosshairs sounds, I think that it would be tricky to implement well. I hope that someone tries it (and many other ideas) and gives these ideas the attention they need to really work. I think LordLocke summarized it well.

Then again, this somewhat follows the trend the DS took- mediocre-to-bad games that overemphasized the touch screen with the occasional shining gem, followed by an era of pretty much ignoring the touch screen existed to get back to creating good games, to finally getting around to figuring out how to make good games with the touch screen used in ways that enhance the game instead of needlessly dominating it.

 

[Jeroen Stout]

Don't get me wrong, but from the moment you can detect rotation, it means you can know the orientation of a device, and from the moment you can gauge acceleration, it means you can know the latest position of same device.
With all this, you could exactly make a pointer. You just need to strap a laser on it.

You're assuming the device never moves when it's powered down.
This is the beauty of the sensor bar for the Wii. Pointing the Wiimote at the screen to activate a game or channel ensures that the main unit can determine the position and orientation after power-up. From there, yes, the accelerometers are sufficent to continue tracking.

The accelerometers aren't precise enough for providing a giroscope-like precision... and on top of that, you can't actually detect rotation over the axis of gravity; the Wii measures three axis with imprecise and clamped sensors. It can nonetheless detect up/down and roll quite well. Rotating over the gravity axis, however, doesn't change any value in the sensors. Horizontal rotation on the Wii usually is detected by the acceleration you make when making a swing and on Wii sports games isn't even a matter of precision but of timing.

I'm running an internship at a company that experiments with the Wii currently, and I've written some scripts for it as well as dissected it. Doing so made me realise what a wondrously simple device it really is, but at the same time it just shows how terribly limited it stays.

Most clever games on the Wii are clever work-arounds rather than the Wii being a great innovation. It's not that it's bad, it's just marketing itself as more advanced than it actually is.

 

[Chilango2]

Um...please don't tell me this is the sort of supporting evidence you'd use in an english paper...it seems like you're just somehow struggling to strap something skill-related to its usage.

1) I'm not writing an english paper. 2) In what world is stratgizing not a skill? I realize that "control over the controller" is a skill, but honestly, its dexterity and eye hand coordination which tends to be more of a "talent" than a skill.

 

[nagumo [deprecated]]

I'm still waiting for that adventure game renaissance.

Yeah right. Have you seen the scores that adventure titles receive from all but sites dedicated to adventure titles? Even the majority of game reviewers fall into the ADD/ADHD crowd. They also seem to rate based upon hype, rather than the actual content in a game. As much as it pains me to say this, the old style adventure game is dead, or close enough to make the call.

 

[Alex Karls]

I'm guessing many here weren't around for the first burst of the 'odd controller' hype. Plastic guns, gizmos and so forth.

Look.

If you want to aim, you need pixel perfect response unless you code in a whole lot of artificial hand-holding and cheating. Any muppet on the Xbox should know this as SR had to do it to prevent the PC crowd running over the corpses of Xbox players chanting 'eat response time, *****' as Xbox owners were the only ones playing the pile of tripe. GoW has stupidly silly amounts of aim aid, and people still suck badly enough for there to be 'amazing snipers' online.

Here's how it goes:

Keyboard/mouse > plastic controller
Plastic controller > vague hand gestures 10' from the screen

The difference between a mouse and a controller is at least 1-2 seconds. I'm not even getting into the RSI issues of having to wave your wand through 35,066 similar enemies - there's a good reason mice rest on flat surfaces where your palm can support it.



Oh. And the only use for duel Wii controllers if you're not amazingly ambidextrous (most people are not) is mutual dildo on vibrate. I'm using this word, as firefox can't spell it, and I personally find this bizarre. Vibrator. Hmm. Might be a USA fascist spelling issue. Armour. Colour. Tomato.

Strange. Stranger still is believing you can wave two white plastic dildos around in the air with any co-ordination unless you're a classical conductor at the Sydney opera house.

So, I'm guessing you haven't actually played with any of the three aforementioned control devices? Because you certainly talk like you haven't.

Doom 3 on the PC?
Halo 3 on the Xbox 360?
Metroid Prime 3 on the Wii?

Because...wow, yeah, I'm hearing hypothesis, but no experimentation to back it up.