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In-depth comparison of the big three's motion controllers.

Forums - Gaming Discussion - In-depth comparison of the big three's motion controllers.

I agree that there is a lot of bashing and misunderstanding regarding these motion capture technology, so I'd like to add some details into this thread to clarify the hardware and software behind these technologies. I don’t work for any of the 3 companies so I don’t have any inside information, but from my experience with these kinds of technologies, I think the things I talk about are likely to be what is going.

First off, the WM+ is using a 3 degree-of-freedom (DOF) accelerometer from the wiimote and a 3 DOF gyro in the add on module to estimate the controller’s position and pose. They carry out the estimation of the wiimote’s posision and orientation by first integrating the accelerometer for velocity and then once more for position, and once for the gyro reading for orientation. Because of the inherent bias in the accelerometer and gyro, they correct the position and orientation using the infrared camera’s observation of the sensor bar. What likely to happen if the wiimote is pointed away from the sensor bar is that the estimation will start to degrade and drift off until the sensor bar is again observed, which will allow the wiimote to again correct its estimation parameters.
Pros: Can be implemented using an Extended Kalman Filter, or Particle Filter (can be computed very quickly), 1-1 wiimote movement in game.
Cons: The IR camera’s field of view is fairly limited, so the estimation parameters can slowly drift if the IR camera is pointed away from the sensor bar for a long time. Only the wiimote’s position and orientation are estimated.

Sony’s solution is fairly similar to the WM+ in that they use a 3DOF accelerometer, a 3 DOF gyro in the wand. The difference is that they don’t have IR camera on the wand, but used a single color camera (sitting on top of the tv) looking at the ob on the wand. The way they calculate the position and orientation  is pretty much the same except the camera’s orb is the observation for the correction step.
Pros: Can be implemented using Extended Kalman Filter, or Particle Filter (can be computed very quickly). Also, the color camera’s field of view is larger than that of the wiimote’s IR camera. 1-1 wand movement in game. Augmented reality (the sword, stop sign demo, etc.).
Cons: The wand’s position and orientation can drift when the ob is occluded. Only the wand’s position and orientation are estimated.

 Natal is a solution that is very different compared to the solutions employed by both Nin. and Sony. They are running a camera fusion algorithm and use the result to perform segmentation (separate the humans from one another and from the background). Afterward, they fit a skeleton model through each of the segmented human volume (mesh) and track the body movement for each of the person in the cameras’ field of view. In addition, they use an array of microphone to process and segment the human speech (I’m not very sure of this part since I don’t have a lot of experience with speech recognition).
Pros: Full body movement and voice recognition. Traditional controller buttons can be remapped to specific action from specific body part (this is not easy and will require some experimentation from the game developers) or verbal commands. Augmented reality.
Cons: Computationally expensive (can be laggy). Full body movement and human activity recognition can be tricky. Occlusion (obviously, the cameras are not going to be able to pick you out if you hide behind a couch or a table). Body movement estimation is locally optimal.

Now for the people who are saying that Eyetoy has been doing the same things Natal is doing, then it is just not true. Eyetoy is a single rgb camera so there is a limit on what we can do with the rgb video stream given that we don’t have unlimited computational power to analyze and extract information from a monocular video. Plus, lighting conditions pose a serious problem for rgb cameras ( it works poorly in dark environment). I personally think that each of the technologies have their own merit and it will be fun to see how they perform when they are released.



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jetrii said:
Staude said:
the natal may be more advanced.. infact yes it is, but the ps eye can do a lot of the same things that it can. Just look at eye pet.

For very basic things like this, yes, both technologies are similar. However, if you wanted to scan yourself into a game, a normal camera like the EyeToy would produce a flat and completely fake looking imagine while the 3D sensor in Natal can produce a 3D model that looks like you. The same is true about scanning objects. When you start to get into more advanced features, the EyeToy is not advanced enough.

Actually i believe the ps eye is more advanced than you think.



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gergroy said:
Random Person B said:

For games microsoft is probably the worst one.
For one simple reason.

Not all video games are played alone


I don't understand what you are trying to say.  The camera can pick up multiple people.  They showed whole families playing a trivia game with one camera, as well as one person acting as the pit crew in the racing game, so... I don't really understand what you are trying to say.  Of all of them, microsoft is probably the best because you don't have to buy a remote for each person that wants to play.

I was thinking about this for a while but how would I play Madden or NHL with my friends with Natal? it would scan the four of us and track different movements from each one of us? I would be very interested to see how it is implemented if such game is released...



MikeB predicts that the PS3 will sell about 140 million units by the end of 2016 and triple the amount of 360s in the long run.

jetrii said:
WereKitten said:
@jetril

As a comment to your OP, something I brought up in another thread though this seems more technically-oriented:

The 1:1 of the Wiimote and WM+ is orientation only (3 degrees of liberty).

The 1:1 of the Sony external camera+wand system is orientation plus positioning tracking (5 or 6 degrees of liberty, not sure about Z axis)

Both the wiimote and Sony wand can detect X,Y, and Z axis movements as well as rotations. Everything the Sony wand did can be done on the Wii Motion Plus. The EyeToy was just used so you can see yourself, it did not have any other function than that. 

Where are you pulling this stuff off?

The Wiimote has an IR camera for pointing and 3d accelerometers, thus it can't detect its absolute positioning if not using the IR. When not pointing towards the led bar, all you have is 3 angles with respect to gravity direction or 3 accelerations. The Motion plus gyroscopes only make those 3 angles more precise. The software can try to integrate the accelerations - if WM+ is present to subtract the gravity- , thus "sort of" computing a 3d position, but it will need to be corrected every now and then by using the IR camera or errors will accumulate.

The EyeToy was not just used "to see yourself": the XYZ absolute position tracking of the wand from the camera was clearly used. See here for an analysis of the patent application Sony submitted, regarding the tech that is probably being used.

Take for example the two-wand manipulation of virtual building blocks demo-ed on stage. You can't do that continuously and precisely with Wiimotes or WM+ unless you restrict yourself to keep them pointing at the screen all the time, in which case from each you still only have 3 positiong degrees from the IR camera and a roll angle (around Z axis). Not the whole 6 degrees of freedom.

Edit: thanks to av36 for really useful and in-depth details. This confirmed what I knew about Wiimote and EyeToy+Wand setup, and I learned more about Natal.



"All you need in life is ignorance and confidence; then success is sure." - Mark Twain

"..." - Gordon Freeman

I for one believe all of this is possible.

I still want to know a few things about the Natal: How much money would it cost to research and develop the drivers for all the advertised features? (Voice control system, accurate motion detection, scan 3D objects in to games.etc.)

Plus what are the hardware manufactoring costs?

How many people would have to buy it to make this investment worth it for them?



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Random Person B said:
gergroy said:
Random Person B said:

For games microsoft is probably the worst one.
For one simple reason.

Not all video games are played alone


I don't understand what you are trying to say. The camera can pick up multiple people. They showed whole families playing a trivia game with one camera, as well as one person acting as the pit crew in the racing game, so... I don't really understand what you are trying to say. Of all of them, microsoft is probably the best because you don't have to buy a remote for each person that wants to play.

The video showing that family playing a trivia game was a concept video All of it was scripted. The important thing about the video was to introduce the possible concepts that could be done with such a device. There is no indication that the current natal can detect multiple people. No where in the live usage did it show any indication it could detect multiple people. If natal works as jetrii says, then there is no way it can differentiate. It at best can make an educated guess. As it is now, it has a way to go before it is fit for video game usage. (multiplayer that is)

You basically stated my point in your response, great job.  (I bolded the important part)  Obviously, if it is a possible concept than it is a feature.  Just because they didn't want to get a bunch of people milling about on stage playing with doesn't mean that isn't a feature. 

I don't see how it couldn't differentiate, one of the key features they were touting was facial recognition.



jetrii said:
the_bloodwalker said:
jetrii said:


Hmmm, I am not fully sure what you're trying to say. Are you saying Natal isn't responsive? I can't comment on whether or not it is, but there is no reason why it would be. A reporter had the chance to play Burnout using the Natal controls and he said it felt very smooth and he didn't notice any input lag.

EDIT: And on that note, I am going to bed. I'll check back in the morning but I suspect that this thread will probably be swarming with people posting comments that are less than intelligent. 

No, it is resposive, but there is no way to deliver feedback to the players except from the audio and video, that's less output to the player than rumble feature and pressure sensitive buttons (like triggers). Unless another device is included and in that sense it will be somilat ro Sony's concept

Ah, now I understand what you mean. And yea, I agree, I imagine some things would feel pretty shallow. If you're using your finger as a gun and have to flick it back to shoot, I can imagine that being enough feedback. However, just holding on to a fake wheel would probably feel a bit too fake for my taste. Honestly, I am more excited about the technology and the cool little tech demoes than actually playing a game with this. I would love to whip out that drawing game when I am with friends and maybe navigate the menus with my hand, but I still prefer a normal controller.

If Microsoft really wants to blow people away, they should let you use your normal controller but add headtracking to the game. With a 3D camera, you wouldn't need anything else for 3D headtracking. That would blow away anything Sony and Nintendo have.

however, on Wii you can do headtracking with another Wii-remote (many homes own more than one) and the extra is just glasses with two infrared leds



the_bloodwalker said:

however, on Wii you can do headtracking with another Wii-remote (many homes own more than one) and the extra is just glasses with two infrared leds

Same with Sony's camera-based system, except that you'd need leds that can be picked up by the EyeToy.



"All you need in life is ignorance and confidence; then success is sure." - Mark Twain

"..." - Gordon Freeman

nice; I really want that Natal but probably too expensive.





Official member of the Xbox 360 Squad

How are you going to walk around in a FPS or TPS or 3rd person adventure melee game with these 3 control methods? Only one of these controllers lets you use a joystick at the same time, which is the industry standard control for movement.