Wednesday, August 4, 2010

Gaming With Nvidia 3D Vision

 Gaming With Nvidia 3D Vision
a 3D dual-projector system, just like in movie theaters. Now, we're comparing it to Nvidia's 3D Vision projector-based setup to see which option offers the best consumer-level 3D experience for your living room.
When we concluded our Wall-Sized 3D Gaming, Just Like The Theaters Do It review, we noted that there could be no proper conclusion until we tested an alternative projector that utilized Nvidia's 3D Vision solution. Well, now you're reading that follow-up article. For those who missed the previous story, we created a 3D projector system similar to the ones used in movie theaters, with two projectors and polarized filters. The whole experiment consisted of about $2,500 worth of hardware and software, not including the PC used to drive the displays.
The main advantage of the polarized system is that it allows for the use of inexpensive polarized 3D glasses. Each pair can be purchased for under a dollar, so adding as many viewers as you like is only limited by the space in your theater room. The main disadvantages of a polarized dual-projector theater are the initial cost, the complexity of setting the system up, and ghosting artifacts in certain situations.

There is another disadvantage that is quickly becoming a much more important factor: Blu-ray 3D. At present, we know of no software that allows a polarized dual-projector system to play back Blu-ray 3D discs, and as far as we know, there are no options on the horizon.

But there is another 3D theater option for the home that offers Blu-ray 3D playback. It is relatively simple to set up, minimizes ghosting artifacts, and has a very low startup cost. That option is an Nvidia 3D Vision-compatible projector.

Stereoscopic 3D and the methods that are used to create it have been thoroughly covered in our Wall-Sized 3D Gaming, Just Like The Theaters Do It and Blu-ray 3D On The PC: The Tom's Hardware Review articles. If you're considering a 3D projector system for your PC, then I suggest looking over the Wall Sized 3D Gaming article, as it has a lot of information about the two alternate 3D theater options. Both of these articles also go over the basics of stereoscopic 3D vision and explain why the key to a 3D display is to provide each eye with an alternate view of the same scene.

For now, we'll cover the main differences between a polarized dual-projector setup and a 3D Vision projector setup.

Polarized Dual-Projection

A dual-projector polarized theater relies on two projectors to deliver video to the screen, while each delivers a unique perspective for a specific eye. Each projector lens is attached to its own polarized filter. The viewer has to wear glasses, but the glasses contain no electronic parts and simply use passive polarized filters. The filter over the right eye will block out the polarized video that is intended for the left eye and the filter over the left eye will block out the polarized video intended for the right eye. This way, each eye only sees its intended perspective, even though both perspectives are displayed on the same screen.

What are the advantages of the dual-projector polarized method for stereoscopic 3D? Most significantly, polarized glasses can be purchased for less than a dollar a pair. Want to invite 20 people over for a 3D party? Less than $20 worth of extra equipment keeps you covered.

What's the downside? The up-front costs are much greater. A dual-projector system requires two projectors. On top of that, you'll need a polarized-compatible screen and polarized filters for each projector. While this might seem like a lot, keep in mind that 720p projectors are available for under $1,000, meaning the total cost of this setup can be kept well under $3,000. The cost is comparable to a single 46" 3D-ready television, which requires at least one pair of expensive glasses to operate.

There are other disadvantages, too. The polarized filters are never 100% perfect at blocking all of the light from one of the projectors, so if there is something dark beside something bright, an eye might notice light intended for the other eye. This is called crosstalk. For me, this usually isn't much of an issue, but it can be quite noticeable in some scenarios. If it doesn't bother you in the theaters, then it probably won't bother you at home. But it is something to consider.

Another slight disadvantage of this setup is that most filters polarize the light across a plane, so the more you tilt your head, the more crosstalk you see.

It is also notable that there is no cost-effective, ready-to-go consumer-level solution for building a polarized dual-projection home theater. The technically-inclined might enjoy the challenge of constructing such a system, but if you don't get excited about big projects, a polarized dual-projection system is not the way to go.

The biggest disadvantage of the polarized method is that no company has announced a Blu-ray 3D software player for it yet. It might happen in the future, but there is a good chance it won't. We've heard rumors that the Blu-ray 3D spec doesn't allow for more than a single display, and the software developers we've talked to have indicated that the dual-projector option is too fringe to justify development. While it's not impossible, it does seem unlikely that we will see a Blu-ray 3D option anytime soon. That means this configuration is pretty much limited to playing games.

3D Vision Projector (Alternate-Frame Sequencing)

Nvidia's 3D Vision solution uses a method called Alternate-Frame Sequencing. Alternate-Frame Sequencing works by alternately displaying a frame of video for each eye. First, a frame of video for the left eye is shown, and then a frame of video for the right eye. This changes back and forth, 120 times each second. The key to making this system work is LCD shutter glasses. These glasses alternatively block each eye at the same frequency (60 times a second for each eye) in order to allow only the intended frame of video to be seen by the targeted eye.

A rate of 60 frames of video per second is what we're used to seeing on conventional LCD TVs. At this speed, you shouldn't be able to perceive any strobing or flickering.

What are the advantages of a 3D Vision projector over a polarized dual-projection system? Foremost, the startup cost is a fraction of any other large-screen 3D Vision setup. A good 3D Vision projector can be found for well under $1,000, including the 3D Vision glasses kit, and only a single projector is required. A 3D Vision projector system is also easy to set up. With only one projector required and no polarized filters needed, mounting the system is relatively simple, and no calibration is necessary.

Another unmistakable advantage favoring 3D Vision and 120 Hz alternate-frame sequencing displays is Blu-ray 3D compatibility. While the 3D Blu-ray specification is said to be display-agnostic, all playback software for the PC relies on this method for full-resolution playback. It might not be practical to view Blu-ray 3D movies at full resolution any other way.

In addition, alternate-frame sequencing all but eliminates ghosting or crosstalk artifacts because each eye is prevented from seeing the image intended for the other eye. It is true that some ghosting might be seen on LCD screens when very bright objects are displayed, but with digital light processing (DLP) projectors, the refresh rate is fast enough to prevent this issue.

All of this sounds wonderful, but there are still downsides to take into consideration. The main problem with alternate-frame sequencing solutions is the high cost of the glasses. For example, Nvidia's 3D Vision kit, including a single pair of 3D glasses and an IR emitter (required to synchronize the glasses to the proper frame of video), is about $200. Each extra pair of glasses after that will typically cost $150 each. So, if you have a family of five and you want to watch a movie on your new 3D Blu-ray home theater PC, it'll cost you about $800 to get the glasses and emitter. Invite a couple to join your family for movie night and the cost goes up to $1,100--and that's not including the cash you already spent on your 3D Vision projector, HTPC, and playback software. On top of this, if your kids are anywhere near as reckless as my own, the risk of damaging those glasses is very real. With each set priced higher than a Wii, you can understand the potential for problems.

Moreover, as mentioned previously, 3D Vision glasses limit the amount of light that reaches the eye, so your display will seem darker than it does when not wearing them. The glasses will also need to be powered. 3D Vision glasses are rechargeable, though, and last for over a day on a single charge, so this is a minor inconvenience. Finally, 3D Vision is not graphics card-agnostic, so if you don't have a 3D Vision-ready GeForce card, you're going to have to get one.

You want to build a 3D Vision projector home theater? Let's go over what you'll need to make it happen.

A Home-Theater PC with a 3D Vision-Capable Graphics Card

You're going to need a GeForce 3D Vision-capable graphics card in your PC. 3D mode will put the hurt on game performance, so you'll want a GeForce GTX 260 or more powerful graphics card if games are on the menu. If Blu-ray 3D is your focus, then you can get away with a GeForce GT 240. The CPU isn't as important, but if you're using a GeForce card that doesn't accelerate Blu-ray 3D, or if you're planning on some serious gaming, you should opt for something well-balance like an Athlon II X3 or Core i3 CPU, at the very least.

We chose the GeForce GTX 260 for our testing, giving us the ability to compare performance to our previous polarized dual-projector theater testing.

3D Vision Kit (Comes with a Single Pair of 3D Vision Glasses)

The 3D Vision kit comes with a 3D Vision emitter and a single pair of 3D Vision glasses. The kit can be purchased for $200 directly from Nvidia's Web store. A single emitter will drive a room full of people wearing glasses, and additional shades sell for $150 each.

We're going to consider this cost as $200 for the time being, but for a family of five, the cost actually adds up to $800 total. Just keep in mind that more glasses equals more money.

3D Vision-Ready Projector

The projector is critical. It has to be 3D Vision-ready. When purchasing a 3D Vision-ready projector for gaming use, you're going to be looking at three factors: brightness, resolution, and cost. Brightness is important because a substantial amount of light from the projector gets blocked when viewed through the 3D Vision shutter glasses. Resolution is important because, when you're playing on a wall-sized display, low resolutions aren't pretty at all. As for price, that's somewhat self-explanatory.

Unfortunately, there are no 1080p 3D Vision-ready projectors out there at this time, but the 720p models deliver excellent image quality, even on a 100" screen. You're going to want a model with at least 2,000 lumens of brightness because you will lose some of the light through those 3D Vision glasses.

We chose the Acer H5360 projector for this review. It's a 3D Vision-ready unit with a 720p resolution, 120 Hz refresh rate, a bright 2,500 lumen output, and a 3200:1 contrast ratio, all for $640 on Newegg. Frankly, we're surprised at the attractive price. It doesn't seem like 3D Vision-ready projectors bear the same price premium associated with 3D Vision-ready LCD monitors. And this projector works great for standard 2D content, too.

You can find a 99" pull-down projector screen for as low as $60 on Newegg. Of course, you could just use a white wall instead of a screen, but let's assume you want to put a little money into something that will reflect the light a little better. We're adding a $60 charge to the bill.

Mounting Hardware and Cables

We found great projector ceiling mounts for $15 each at DVI-to-HDMI cables are also nice to have, and we paid about $25 total for a 25 ft. cable. The mounting hardware and cable adds up to $40.

What's the Total?

We're going to leave out the price of the PC from this setup, as folks may opt to use their existing PC to drive the wall-sized 3D display. All of the other costs add up to a final total of $920 for 3D Vision-display hardware.

This costs far less than our polarized dual-projector system, which weighed in at about $2,500. The financial advantage for the polarized system is, of course, that additional glasses can be purchased for under $1 each. Then again, you can buy a lot of $150 3D Vision shades for the $1,500 price spread between these display technologies.

Installing a 3D Vision projector system is incredibly easy compared to setting up a polarized dual-projector system. For example, you do not have to worry about filters that need to be mounted or screen calibration. Some hardware mounting is involved, but it's a straightforward affair.

Before you do anything else, plug your 3D Vision glasses into the included USB cable to charge them. There's nothing worse than having everything else ready and no glasses to use.

Now you want to install the screen, and to do that, you'll want to test-fire your projector and see how far away from the screen it will have to be placed to produce the image size image you'd like. When this is done, you should have a good idea of where everything will be placed. Projector screens are often attached to the wall/ceiling by a few screws, which is not difficult to do.

With the screen installed, you move onto the projector mount. Ideally, you'll find a centered ceiling joist to carry the weight of the projector and mount it there. Every mount has its own particular mechanism for bolting to the projector, which is usually mounted with three small screws to secure the base.

With the hardware mounted, power and display cables need to be routed to the projector. In our temporary setup, we simply mounted the cables to the ceiling, but a permanent solution would probably benefit from a stealthy installation behind the wallboard or ceiling tile.

With the projectors mounted and cables attached to the PC, it's time to turn everything on. A quick note about the Acer H5360 projector: there is a 3D Vision option in its menu. Our testing shows that this option does not enable 3D Vision. Instead, it provides a number of extremely irritating messages whenever the resolution is changed. You should probably keep this option off if you value your sanity.

With everything powered up, you install the newest GeForce drivers that include all of the necessary optimizations for 3D Vision. In this case, we're using build 257.21, but there is a newer package on Nvidia's site. After installation, make sure you set the display resolution to 1280x720 at 120 Hz. This is critical because lower refresh rates will not work with 3D Vision. With this done, you can enable 3D Vision and test it out.

The 3D Vision controls are in the Nvidia Driver Panel, and the first time you try to enable the feature, you instantiate the 3D Vision wizard. It's a helpful little app that simplifies the setup of 3D Vision and makes sure everything is working well.

The 3D Vision wizard ensures the display is working properly with the emitter and glasses by displaying some imagery and quizzing you about what you see. After the wizard is certain everything is working, you are prompted to click the “Test Stereoscopic 3D” button in the driver panel for a full-screen 3D video test.

There is an important detail to note when using Acer's projector for 3D Vision duty: 3D mode only seems to work properly at 1280x720 using the 120 Hz refresh rate. This means that you will have to run your games at this setting in order to view them in 3D. Interpolating higher resolutions down to the monitor's native resolution will not work in 3D mode.

This nostalgic test is the same one Nvidia's 3D driver has been using for years--you can tell by the old rendition of the Nvidia logo--and it continues to do a fine job of letting you know if 3D is indeed working on your system or not.

To view this cross-view image in 3D, read the instructions on the test setup and benchmarks pageTo view this cross-view image in 3D, read the instructions on the test setup and benchmarks page

During our setup stage, we had two issues that were both illuminated by the 3D Vision setup wizard. First, the system did not automatically recognize our 3D Vision IR emitter. This is a rare problem in the wild, but we've experienced it a number of times with our particular sample. In any case, the problem is solved by manually applying the nvstusb.inf driver from an older 3D Vision driver.

Our second issue was a bit more disturbing. The PC did not detect our Acer H5360 projector when we used the HDMI input, and since it wasn’t detected as a 3D Vision-ready display, 3D Vision would not work. We worked around this incompatibility by using a VGA cable instead of an HDMI connection. The tradeoff here is that HDCP compatibility is lost over VGA, resulting in a loss of resolution during Blu-ray playback.

3D Vision is somewhat simple to use, and in many cases, tasks are handled automatically. However, there are a few things to keep in mind.

Operating the 3D Vision IR emitter

You'll need a clear line of sight to the emitter from your seating position because it sends a signal to the 3D Vision glasses that synchronizes them to the display. It won't work if the emitter is behind you. The good news is that the emitter outputs a strong IR signal that works as far as 30 ft. away, so a number of people can use the same emitter at the same time.

There are two controls on the emitter: an On/Off button for the 3D effect and a depth wheel at the rear. The On/Off button is self-explanatory, while the depth wheel increases or decreases the depth of the 3D effect. The best way to understand what it does is to try it out. Simply set it to taste.

Launching a Game

Once you have enabled 3D Vision, it will automatically become active whenever you launch a 3D game. 3D Vision will show you a heads-up display with information about how well 3D Vision works with the title, if any information is available. Typically, the overlay will give the game a rating such as “Good” or “Not Recommended” and describe the in-game settings you might want to tweak to minimize 3D anomalies, if possible. When you're done examining this information, you can make it disappear by hitting the Ctrl-Alt-Insert keys.

The Depth Issue

This brings us to an unpleasant, but workable, issue that we encountered: a lack of apparent 3D depth in some games when using 3D Vision.

The 3D depth hinges on two factors: separation and convergence. Both of these factors must be set properly for a good 3D effect. Nvidia has supplied a very convenient separation control on the 3D Vision emitter (the depth wheel), but the convergence control is much harder to find. The setting is actually disabled by default and must be enabled in the "Set keyboard Shortcuts" pop-up menu in the "Set Up Stereoscopic 3D" panel of the GeForce driver.

In most games that Nvidia has profiled, it has created a default convergence setting that facilitates a reasonable 3D effect. Unfortunately, there are some games for which Nvidia has not created a profile, and if the default convergence setting isn't quite right for the game engine, the 3D effect will be poor, regardless of what the depth wheel is set at. Naturally, this is something that Nvidia has the power to affect with driver updates, and the good news is that the company continues shipping newer software to keep 3D Vision up to date.

Another issue with the convergence controls is a lack of user feedback. Increasing or decreasing convergence might have a very subtle effect for a long time before you notice any difference on screen, so some feedback about Nvidia's 3D Vision HUD would be appreciated here. Essentially, we think that the critical convergence control should be enabled by default and that there should be some user feedback when the controls are operated.

As for separation, the depth wheel on the 3D Vision emitter doesn't allow us to increase the apparent 3D depth past an arbitrary value that we feel is too shallow in some of the games we tested.

3D Vision allows a maximum depth setting based on the size of the display you are using and the display size is hard-coded based on your 3D Vision-compatible device. In the case of the H5360 projector, though, the screen size is variable--there's a huge range of possible screen sizes. Nevertheless, the 3D Vision driver decided on a 110" screen size, and that's what we had to live with.

Traditionally, Nvidia's 3D drivers have offered screen size settings, and because the maximum depth is based on the screen size, it could be used to manipulate the maximum depth. A smaller screen size setting allows for a larger apparent maximum depth. Unfortunately, the new drivers do not allow the user to manually select the screen size for a known 3D Vision display. Nvidia could easily fix this issue for everyone by allowing advanced users to set their own screen size in the driver panel, and we requested that in our feedback.

Left 4 Dead simply has to be one of the test cases for a wall-sized stereo 3D experience. And I'm not talking about Left 4 Dead 2 (the sequel with its bright outdoor environments). I'm talking about the original, with its dark, claustrophobic corridors and rainy nights. This game is very well suited for 3D play and brings the experience to life in a way that's hard to describe, but awesome to behold.

We use the following settings for our tests: 1280x720 (native projector resolution), highest details, and 4x multi-sample anti-aliasing (MSAA).

Game Experience using 3D Vision:

Nvidia considers this game worthy of the “Excellent” rating, and we certainly agree. Left 4 Dead delivers a very smooth 3D experience with no visual anomalies to note.

The specific info delivered in the 3D Vision game rating overlay is "Rating: Excellent, Clouds at wrong depth, Setting film grain to off provides better stereo effect." Strangely enough, I don't notice anything in the way of cloud-oriented anomalies.

The only thing we can complain about is that the maximum depth allowed by the 3D Vision driver seems slightly shallower than what we would like, as we've mentioned previously. However, this can be improved with convergence controls.

Comparing with the Polarized Dual-Projector Drivers:

The TriDef drivers perform just as well as the 3D Vision solution in Left 4 Dead, but the iZ3D drivers are lacking in that there are a number of text overlay and skybox anomalies.

TriDef Ignition Driver Screenshots:

iZ3D Driver Screenshots:

Note the distracting inconsistency in the placement of the character names above their headsNote the distracting inconsistency in the placement of the character names above their heads

Left 4 Dead 3D Stereo Performance:

The 3D Vision driver delivers much better performance than the iZ3D driver can muster on the GeForce GTX 260. From a raw performance standpoint, the iZ3D and TriDef drivers deliver almost identical performance compared to the Radeon HD 4890. Note that the TriDef drivers do not work on the GeForce card in this game.

I can't think of a racing title I'd rather play to experience the ugly fun of high-speed collisions in stereo 3D. For the record, this game gets the most traction out of the titles I demonstrate when people come over to experience wall-sized 3D gaming. Burnout is very accessible, and players never seem to tire of racing through ParadiseCity. High-speed crashing and jumps in 3D never get old.

We use the following settings for our tests: 1280x720 (native projector resolution), highest details, and 8x MSAA.

We use 8x MSAA with this title because, for whatever reason, Burnout Paradise is a game that seems to highlight jaggy edges at low resolutions. So, 8x MSAA is how we counter that.

Game Experience using 3D Vision:

For Burnout Paradise: The Ultimate Box, 3D Vision has the following to say when it comes to compatibility: "Rating: Good, some objects render incorrectly."

After putting some time into the title, I have to say it's hard to believe it was given the same rating as Crysis. This game works a heck of a lot better than Crysis in 3D mode, and it appears just fine with all of the bells and whistles enabled.

Comparing with the Polarized Dual-Projector Drivers:

Burnout Paradise: The Ultimate Box works very well with the TriDef driver, but the iZ3D driver suffers from shadow artifacts and glitches that spoil the experience.

TriDef Ignition Driver Screenshot:

iZ3D Driver Screenshot:

Note the extra random shadows all over the road compared to the TriDef driver. These shadows crawled all over the place while drivingNote the extra random shadows all over the road compared to the TriDef driver. These shadows crawled all over the place while driving

Burnout Paradise 3D Stereo Performance:

Burnout Paradise is the biggest disappointment in our test suite as it pertains to 3D Vision. This is due to poor performance and not because of poor visuals. The good news is that lowering shadow detail makes the game run a lot smoother, and 8x AA can be enabled because it doesn't seem to have an effect on performance.

Epic space battles in wall-sized 3D are so impressive that this is a crowd-favorite game to sit back and watch. The sense of scale is simply breathtaking with the camera poised behind the saucer section of a mighty starship that fires volley after volley of phaser cannons toward a target far off in the distance. Floating space debris contributes to a sense of depth.

We use the following settings for our tests: 1280x720 (native projector resolution), recommended quality, and 4x MSAA.

Game Experience using 3D Vision:

The 3D Vision adviser tells us the following about Star trek Online compatibility: "Rating: Good, Some objects render at wrong depth, Go to Options/Video turn on advanced video settings, Anti-Aliasing=None, Shadows=low, Bloom Quality=Off."

Essentially, shadows don't render properly. But it turns out that space battles don't need shadows to look great. And if AA is enabled, some stuff renders in one eye and not the other (explosions and certain weapon effects are two examples), but turning AA off fixes this issue. On a positive note, the mouse cursor is shown for both eyes, which is an improvement over the iZ3D driver.

This is one of the titles where we noticed a lack of depth on the projector compared to other 3D solutions, such as the polarized 3D drivers or even 3D Vision on the Acer GD235Hz LCD monitor. The depth wheel could not correct the lack of depth, but extensive tweaking with convergence helps produce great results.

Comparing to the Polarized Dual-Projector Drivers:

Unfortunately, this is another game for which the TriDef driver fails to work on a dual-projector system. As it always seems to, the iZ3D driver works, but produces some shadow glitches, so the low setting is necessary. Once again, the mouse cursor can only be seen in one eye when using the iZ3D driver.

Star Trek Online 3D Stereo Performance:

This game favors the 3D Vision solution, delivering higher frame rates than the iZ3D driver provides on the GeForce GTX 260.

Something that polarized dual-projector systems do not currently allow for is Blu-ray 3D playback. This is a software, and not a hardware, limitation. No developers are spending resources to design something for the fringe dual-projector platform.

Of course, 3D Vision uses the same 120 Hz AFR method to display 3D imagery that the major television manufacturers are using, so this de-facto standard is supported through 3D Vision by all the significant Blu-ray 3D software packages. In our case, we'll use a prerelease version of PowerDVD 10 Ultra Mk II to test things out. We're using the newly released Blu-ray 3D disc Cloudy with a Chance of Meatballs.

The Blu-ray 3D playback is perfect, and surprisingly bright. We are put off by Blu-ray 3D playback on the 3D Vision-capable Acer GD235Hz LCD LCD, but the brightness issue doesn't seem to rear its head on the Acer H5360 projector. Perhaps we're simply conditioned to control the light in a projector situation. But whatever the reason, the brightness isn't a detractor at all like it is on the monitor.

No comments:

Post a Comment