View Full Version : Head Tracking/Stereoscopic 3-D?

5th Apr 2009, 22:28
The TrackIR system is really cool, and things like the Vuzix goggles are really coming along. It would be cool to see it supported, especially if it could be like you use the head tracking to look around and aim, but the mouse still works to turn your body, or you can look around, but you turn and aim with the mouse. Maybe the player can tweak which way it works?

And I don't know what if anything you guys need to do to get the 3-D effect supported, but I'm guessing that's already in the cards, since it's getting more popular now.

The more innovative technology DX3 supports, the better. Not only will it enhance the experience, but the game itself could help push gaming technology forward by giving gamers the incentive of playing a triple-A title in this manner, and more people will get these devices.

I've wanted to try this stuff out, but nothing that's been released so far has really made me want to spend the money. When it becomes more common and cheap, I'm sure it'll be everywhere.

5th Apr 2009, 23:58
Yeah, the graphics hardware is already capable of stereoscopic 3D output. You just need drivers that will actually tell your hardware where to send each output buffer. And, of course, you need a system that distributes it to two different eyes. That can be achieved by either a head-mounted pair of monitors, like the Vuzix, or you can have a regular monitor and shutter glasses. Shutter glasses are usually LCD based, and they simply keep only one eye open at a time. The problem with this is that LCD monitors, that most people are using now, are too slow for shutter glasses. You really need a CRT screen for that.

This does work a little better if it is explicitly supported by the software. I have spent one summer writing 3D visualization software to run on nVidia Geforce FX card with a quad-buffer. Normally, when you render to OpenGL, you have two buffers: Front and Back. You render to Back buffer, then when everything is there, you swap them. Front becomes Back and vice versa. Operating System uses Front buffer to put things on the screen during every screen update. That prevents flickering. When quad-buffering is enabled, you end up having Front_Left, Front_Right, Back_Left, and Back_Right buffers. You render to Back_Left and Back_Right with slightly shifted point of view. Other than adjustments to modelview transform, the passes for the two buffers are identical. The Operating System then grabs Front_Left and Front_Right every other frame. There is also an IR port that sends a left/right switch signal to the wireless shutter glasses. So everyone in the room sees image from Front_Left buffer with left eye, and Front_Right with the right eye.

There is special software that can intercept OpenGL calls to render to Back buffer, and with adjustment to the modelview matrix send them to both Back_Left and Back_Right buffers instead. (In actual implementations, Back and Back_Left are usually the same buffer.) This allows stereoscopic 3D in software that doesn't explicitly support it. This tends to work in games, but there can be serious artifacts. For example, when HUD is rendered, sometimes the matrix is switched to orthonormal projection, and the depth is used simply for layer indexing. This can cause the HUD to be at completely wrong depths when viewed through shutter glasses.

I never worked with stereoscopic stuff under DirectX, but having worked with regular 3D graphics, I imagine it is almost identical.

So the point is, if the developers actually take this into account, they can make stereoscopic 3D work really well. It is a fairly minor alteration to the engine, so it can be done without breaking anything. If they don't bother with it, you can still get it to run in stereo, but you might run into very annoying artifacts.

6th Apr 2009, 06:32
Fancy as all that 3D tech is, some of us are stuck with glasses. I don't like any technology that relies on a pair of goggles in order to create such an effect.

6th Apr 2009, 23:42
Fancy as all that 3D tech is, some of us are stuck with glasses. I don't like any technology that relies on a pair of goggles in order to create such an effect.

There's some reason for that, I assume?
The Vuzix goggles are basically like sunglasses. Wouldn't you just feel even more like Adam Jensen then? :cool:

7th Apr 2009, 00:47
Fancy as all that 3D tech is, some of us are stuck with glasses. I don't like any technology that relies on a pair of goggles in order to create such an effect.
Most shutter goggles can be worn over glasses. And Vizux makes some screens that have optics with vision correction. Though, they probably don't account for astigmatism yet. Still, it shouldn't be too long until you'd be able to order these with prescription lenses built in.