[Basic]

While I'm sure Parhelias "Surround Gaming" gives a cool feeling, it might not be exactly what it seems. I've got the impression that it's acheived by simply rendering to a three times wider framebuffer, and then split that to three screens. If it's done this way, then the monitor setup that is shown in all PR is incorrect. The peripheral monitors should not be turned into the user, but should instead form one flat wide screen. The reason is that the image in the peripheral monitors will be stretched in such a way that any other position will get incorrect perspective.

If you start from the standard fov 90º, then the resulting fov will be 2*atan(3*tan(90º/2)) = 143º, or in other words 26.5º+90º+26.5º. So you certainly won't see three times as much. An interesting thing though is that if you start from a lover fov, then the peripheral monitors will give you more information (ie 30º+60º+30º = 120º). This will of course reduce total vertical fov, but there's a chance that the imersiveness increases since the rendered fov will fit better to the fov the monitors actually take up of your vision.

However, to get the most out of the three monitors, you should be able to turn them so all of them are facing you straight on. But to do that, you'd need to do separate geometry calculations for each monitor. It's not impossible to do it transparently in the drivers/hardware, but I have my doubts that they actually done it. (Hats off if have though.) They wouldn't need to redo the whole vertex shader, it should be sufficient to multiply the final vertex with a "relative projection matrix", and redo the setup for each monitor the primitive is displayed on.

It would be interesting if someone with contacts with Matrox could ask for some clarification about how it's done.

[Mintmaster]

You're right Basic. Actually, I was thinking the same thing. I'm quite sure that "Surround Gaming" uses 3 times the width for the frame buffer. You would get very strange projection effects on the two side monitors. An object could look huge in the side monitor, but when you turn to face it, it would be much smaller in the main monitor.

Using your example of 90 degree FOV, an object on the far edge of the side screen would be tan(143/2) = 3 times (!) as big than when in the middle of the centre screen. This would only be a correct image if the user was looking at the monitor so that it had a 90 degree FOV in real life, i.e. 7 inches from a 19 inch monitor screen, and the layout is flat as you said. In this case, the increased distance of the side monitors from the viewer would compensate for the bigger size.

However, I seriously doubt people play a game that close to the monitor. Also, the extra monitors would be quite ineffective at such an extreme viewing angle, as shown by your 26.5 degree calculation.

I think the purpose is really just to have the side monitors for peripheral vision, no more. You can see someone there in the corner of you're eye and then turn in that direction with your mouse, not your head.

Surround gaming, I think, is far less useful than the general ability to have 3 monitors for increased productivity, or for extra information like in some flight simulator games.

EDIT: Okay, 7 inches from a 19" monitor is not quite right, due to the border around it. Its more like 9 inches. But that's still pretty close. If you were the normal 20 inches from the centre screen, the side objects would be almost 2 times the size they should be, and the perspective problem would make it look funny.

[Mintmaster]

I also noticed this horibble perspective problem with increase FOV in another game. Anyone remember Duke Nukem 3D? When you looked up, the projection plane remained perpendicular to the floor. Objects weren't actually rotated around the camera point like in Quake, but the camera panned upwards along the same projection.

I thought it was pretty lame of the coders to leave that out of the game engine. Apart from mathematical stupidity, it could only be attributed to making a 2x2 rotation matrix instead of a 3x3. It would save some geometry calculations, but that game was hardly geometry limited, as it was software rendered. Totally unforgivable

[Basic]

That trick is actually mostly about the rasterization. You can optimize away a lot of perspective correction calculations, and it makes the rasterization a lot simpler. Just think about it, a vertical line on the screen becomes just a stretched version of a vertical line in the texture.

But that's ancient, software rasterization stuff. (Even though I know of hardware that do the same trick.)

[Tagrineth]

Uhm, the Quake3 Engine features adjustable FOV...

Same with the Unreal Engine...

All Q3A-based games and Unreal-based games will support Surround Gaming with a ~180º FOV. Spreading that across three monitors will eliminate the odd stretch effect which comes from using 180º on one monitor.

Heh, just noticed that Doom Legacy also supports an adjustable FOV. DOOM on three monitors...

[SA]

Providing separate geometry calculations and user selectable FOV for the 3 monitors is really the only way to go in the long run. This allows the user to angle the monitors as they choose, which may vary depending on the size of the monitors.

I am just glad to have a 3d hardware vendor support the surround feature in the first place. The rest will follow.

[Jerry Cornelius]

I think Duke Nukem was built on an engine written by a 17 year old. Quite an acheivment considering it was one of very few (2?) "3D" engines at the time. Looking up and down was a feature that I don't think Doom had. It was a hack, but those engines didn't do any real 3D, so trick would be a better term. DN didn't have any polygons, just zones that were made by cutting out a peice of the floor and moving it up or down.

Remeber, these were software renderred on 486s.

[Basic]

Tagrineth:
Adjustable FOV in the game is neccesary if you want out of the box compatibility for old games, but it doesn't help the inefficient use of the side-monitors with high FOV. (Assuming that the screen is rendered as one flat surface.)

I don't know about Q3, but Q2 won't display fov higher than 160º. And even if it could, it would be of little use. If you wanted that fov over three monitors, you would get the fov-distribution 18º+124º+18º. Pretty much no information on the side-monitors.

Looking at the surround_quake3.avi from matrox, it seems as they are rendering to a flat surface, and opting for lower FOV. But it's difficult to say, and I couldn't find enough geomtry in that demo to easily calculate what FOV they've used.

I fully agree with SA here, in the long run the monitors should have separate geometry calc, with a user-defineable "relative projection matrix". (But preferably in a more user friendly format than a matrix. )

And if they could suply a flexible way to decide where to render and with what geometry warp, then it would be usefull for another kind of surround gaming. - Anybody from Dimension3D remember something that I called a "Personal CAVE"? Using a large monitor, a projector, and a folded projector screen around the monitor. Giving a true 180º fov, and even extending the image to straight above your head.


Jerry:
In doom there was no look up/down, but DoomII used the same trick as DN. (If I remember correctly.)

[Nappe1]

Originally Posted by Tagrineth

Uhm, the Quake3 Engine features adjustable FOV...

Heh, just noticed that Doom Legacy also supports an adjustable FOV. DOOM on three monitors...

damn you!
Now I must buy 2 more 21 inchers!
Doom Legacy kicks serious butt!

[Colourless]

Quake 3 (and probably all quake 3 engine games) support custom screen modes as shown in this pic here. However thet HFov is still only 90 in that pic. To be useful it needs to be increased.



Just FYI that mode is a 800x200. The aspect frame buffer is what you'd get with Matrox's Surround Gaming.

I'm pretty sure it is showing exactly what Mintmaster was describing where the side walls are really big.

[ADDED]

Here's 2 better shots with an increased fov to 143. They are both standing in the same spot.



-Colourless

[Tagrineth]

Originally Posted by Basic

Jerry:
In doom there was no look up/down, but DoomII used the same trick as DN. (If I remember correctly.)

Even DOOM64 didn't support look up/down, and that one actually has a true 3D engine, including the ability to go over and under the same objects, which ISN'T present in the PC DOOM series.

[rayle^extropy]

Actually, (and I'm no coder or 3D expert, so pardon my hubris here) as far as I know, the technique used in the BUILD engine and the Doom engine to provide look up/down is called Y-shearing. I don't know how it works, specifically, but I'm sure you could Google it and find out. And yeah, it was a hack. The games that supported this were Heretic, Hexen, Duke Nukem 3D, Shadow Warrior, Blood, CyClones (using a proprietary engine by Raven Software prior to Heretic or Hexen which supported look up/down, a true 3D automap, aiming independent of looking, and also true 3D gameplay and slopes - but no angled walls here, buddy - IIRC all the walls were at 90 degree angles from each other, wolfenstein-style) and probably countless others. I think Rise of the Triad used that technique.

It's worth looking into.

By the way, check out www.doomworld.com if you don't already. ^_^

-Katarhyne, Doomworld newsie

edit: Neither Doom nor Doom II supported looking up/down.

[pcchen]

IMHO assuming the focal length and the actual configuration of the monitors are already known, it should be possible to "warp" images on the side monitors from the triple width frame buffer.

Of course, it is still better to have application controlled matrices. On a multiple display system, an application can use multiple windows to archieve simlilar effect, at least in OpenGL.

[mangrove]

Originally Posted by Tagrineth

DOOM on three monitors... :D

Actually that's pretty old -- even the original Doom could support that. Well, it involved using three networked computers, and I think it was only enabled in a beta -- 1.5? Too long ago...

[Hellbinder]

The biggest problem with surround gaming is this...

COST.

Kick out 400$ for a Video card and another 500-1500$ on additional monitors/flatscreens... Just to play outdated Games that no one else is playing anymore...

Then What about in 12 months when the next wave of games comes out that likes the 8 pipelines of the Nvx and Rxxx... Will you really do FPS surround gaming if it is only running at 30 FPS? or less? Then you better pray that driver support is solid, and Everyone stops using Stencil buffers...

I just dont think that anyone but a VERY FEW people can afford this clearly short lived habbit...

[JF_Aidan_Pryde]

Originally Posted by Hellbinder[CE

]The biggest problem with surround gaming is this...

COST.

Kick out 400$ for a Video card and another 500-1500$ on additional monitors/flatscreens... Just to play outdated Games that no one else is playing anymore...

Then What about in 12 months when the next wave of games comes out that likes the 8 pipelines of the Nvx and Rxxx... Will you really do FPS surround gaming if it is only running at 30 FPS? or less? Then you better pray that driver support is solid, and Everyone stops using Stencil buffers...

I just dont think that anyone but a VERY FEW people can afford this clearly short lived habbit...

In 12 months time developers might start using DirectX8 properly. Tim Sweeney seems to be very happy with how his UT2003 is running on three monitors.

Yeah, few people, just like how market analysts kept on telling 3dfx there's only a few people willing to pay for high end 3D. By your grand theory of relativity, Voodoo2 SLI should have been a total flop.

[Foodman]

I'd love to have 3 monitors. And as soon as I have a "real" job, I'm gonna get me some.

[muted]

well , i'm buying a new system, and i already have money set aside for 3 new 19" monitors.. and .. for a new desk ..

[Tempest]

Hi, we just got a posting from a Matrox employee, this might clarify or at least verify some of the things you've been pondering...

In order for Surround Gaming to work, you need to have the following:

- Custom video resolution support (Some games only allow 640,800,1024 etc...) Without that, you can't have it. There are ways you can edit .ini or hack the registry, but usually it's not supported.
- Adjustable FOV (This is important, for FPS such as Quake 3, SOF2, UT 2003 and so on), without this, again things will look stretched.
- Aspect ratio needs to be maintained (Some games lose the vertical size) ie: 4:3 to 4:1

Like i said before, we are trying to compile a huge list of what works fine, good and great with Surround Gaming.

Right now i am working with several developers on supporting true Surround Gaming, which is the equivalent of 3 viewports. This will show in games like IG3 where we have something happening on each screen. There will be other surprises happening on E3, which are games running on Parhelia but not been announced yet, yet they're running in Surround Gaming and so on....

Also here is a screenshot of UT2003 running at 3840x1024 :P

[muted]

Well , what other games could that be ?

hmmm ... hmmm