3D Vision Blog

HDMI Licensing has announced the release of HDMI Specification Version 1.4a featuring some enhancements for 3D applications including the addition of mandatory 3D formats for broadcast content as well as the addition of the 3D format referred to as Top-and-Bottom. An extraction of the 3D portion of Specification Version 1.4a is also freely available for public download on the HDMI Web site in order to provide public access to the 3D portion of the HDMI Specification for those companies and organizations that are not HDMI Adopters, but require access to this portion of the Specification.

Having set a complete set of Mandatory 3D Formats in HDMI Specification Version 1.4 (with the updates available in 1.4a), the association is trying to ensure interoperability for devices designed to deliver 3D content over the HDMI connection. Implementing the mandatory formats of the HDMI Specification facilitates interoperability among devices, allowing devices to speak a common 3D language when transmitting and receiving 3D content. Or in plain words that means that you’ll be able to plug in your PlayStation 3 console, when it is updated to support stereo 3D, into a 3D-ready Samsung HDTV for example and not only having to use it with a compatible Sony TV set. Here is a list of the mandatory 3D formats that should all be supported by all compatible displays to ensure full compatibility…

For movie content (like Blu-ray 3D)
- Frame Packing: 1080p @23.98/24Hz

For game content (like PS3)
- Frame Packing: 720p @50 or 59.94/60Hz

For broadcast content (like 3D TV)
- Side-by-Side Horizontal: 1080i @50 or 59.94/60Hz
- Top-and-Bottom: 720p @ 50 or 59.94/60Hz or 1080p @23.97/24Hz

For more information you can go and download the updated 3D portion of the HDMI Specification Version 1.4a form the official HDMI website as it is freely available to anyone interested, you just need to fill in a form with some information.

- To download the updated 3D portion of the HDMI Specification Version 1.4a…

Digging trough some programming documents on Nvidia’s website I was able to find something interesting in one quite old document, regarding programming for GeForce 7 series, but these are still mostly the same issues that bring problems to current games when you try to play them in stereo 3D. I’m citing the part where Nvidia talks about these common issues and suggests workarounds (in terms of programming the game) for them below, because you need to be aware of these in order to be able to avoid most of them by changing settings in the game options etc. If you know what hurts the game looking good in stereo 3D mode you may be able to disable some of the problematic things or lower their negative impact with lets say custom convergence, so that the game will still be playable and look nice. And although these are related to Nvidia’s stereoscopic 3D drivers (prior 3D Vision) they do apply to 3D Vision and other alternative solutions that allow you to play a game in stereo 3D mode…

Rendering at an Incorrect Depth
This problem is the number one thing you should take care of. The 3D Stereo Driver uses the depth to create the stereo effect, so anything that is not at the correct depth stands out like a sore thumb when viewed in Stereo.
- Place background images, sky boxes, and sky domes at the farthest possible depth. Otherwise, the world will look like it’s in a little box in stereo.
- Place HUD items at their proper 3D depth. If you have name labels that hover over objects, putting them at the 3D depth of the object gives a better stereo effect than putting them on the near plane of the view frustum.
- It’s also helpful to render the HUD as far into the scene as possible. This trick gives you a greater perceived depth in the rest of your scene while not causing eyestrain when looking at the HUD.
- Laser sights, crosshairs, and cursors do not look correct unless placed in the 3D world at the depth of the objects they are pointing to. When they aren’t, it is almost impossible to use them since the user’s eyes are converging on one depth, but the cursor is at another depth; users see two cursors, neither of which point at the correct place.
- Highlighting objects should happen at the depth of the object itself, not in screen space.

Billboard Effects
Billboard effects look flat and bad in regular 3D; they look even worse in stereo. In regular 3D you see the billboards as you move around, but in 3D Stereo the problem immediately pops out at you, even in a static scene. Most billboard effects look extremely flat in stereo, so use real geometry everywhere you can instead, even low resolution geometry looks better. For particle effect billboards (sparks, smoke, dust, etc), these may or may not look ok, the best thing you can do is test your app in stereo to see what it looks like and judge if the quality is good enough, and make sure that the billboards have a meaningful depth in 3D.

Post-Processing and Screen-Space Effects
2D screen-space effects can greatly hurt the stereo effect. Things like blurry glow, bloom filters, image-based motion blur fall into this category. These effects are usually created by rendering the 3D geometry to a texture, then rendering a 2D screen aligned quad to the screen. The geometry in the texture is no longer at the correct depth in the world as the effect should be, thus working poorly in 3D Stereo. You should provide the option to disable these effects for people playing in stereo and render the geometry to the back buffer.

Using 2D Rendering in Your 3D Scene
Any object rendered as 2D doesn’t really have a real 3D depth, so it is placed at the monitor depth. This will look very flat in 3D Stereo. If you are mixing 2D and 3D in your HUD you may have inconsistent depths leading to eye strain. Again, render everything at the proper depth, in 3D, and test with stereo on.

Sub-View Rendering
When rendering a sub view to the screen, such as a picture in picture display, car mirror, or small map in the upper corner, you must set the viewport to cover the area before rendering. This trick prevents strange stereo effects bleeding outside of the intended section of the screen.

Updating the Screen with Dirty Rectangles
If you are determining only the parts of the screen that have changed and not updating the rest of the screen this can cause odd looking rendering in 3D stereo. Just render all visible objects each frame.

Resolving Collisions with Too Much Separation
If you are resolving collisions by pushing objects away from each other, make sure you don’t push them away too far. It looks bad in normal 3D when moving around but stands out right away in stereo, making things appear to hover above the ground.

Changing Depth Range for Difference Objects in the Scene
Splitting the scene into multiple depth ranges can cause distortions in the stereo effect making some objects look shorter or elongated. All objects should be rendered in a consistent depth range for the best stereo effect.

Not Providing Depth Data with Vertices
When sending vertices for rendering to D3D for software transform and lighting, include the RHW depth information for stereo to function properly.

Rendering in Windowed Mode
NVIDIA’s 3D Stereo only works when your application is in full-screen exclusive mode. If you don’t support fullscreen mode, then game players can’t take advantage of 3D Stereo.

Shadows
Rendering stencil shadows using a fullscreen shadow color quad will not work properly in stereo. However, re-rendering shadowed objects in the scene at their proper depth in shadow color will function correctly in stereo. Shadow maps function fine, and projection shadows function as long as you are projecting to the proper depth for the shadow.

Manually Writing to Render Targets
Don’t lock render targets and do direct writes; doing so bypasses the stereo driver.

Very Dark or High-Contrast Scenes
Very dark scenes can become even darker when using 3D Stereo shutter glasses. Providing a brightness or gamma adjustment will help this problem. Using very bright objects on very bright and very dark objects causes ghosting, which hurts stereo. Testing your game in stereo quickly shows whether or not this is a problem.

Objects with Small Gaps between Vertices
Small gaps in meshes can become much more obvious when rendered in stereo. Make sure your meshes are tight and test in stereo to be sure this isn’t happening.

- Download the complete GPU Programming Guide Version 2.5.0 in English (PDF)…

This summer should be big for all the major TV brands that are going to release the new wave of 3D-capable HDTVs, or at least everyone hopes it to be like that and expects this to happen, but will it turn out as expected or not is another thing. It very much depends on how many early adopters will go for the 3D technology on a TV for more general use and not just for specifics like gaming in stereoscopic 3D which is something that you can even do at the moment with a 120Hz monitor. A 3D-capable HDTV will bring you a bigger screen which is best suitable for movies, but you’ll be getting the whole thing – 3D photos, movies and games.

If you’ve been watching closely nobody besides Sony is talking about stereo 3D gaming, but Sony is doing this related to their PlayStation 3 console only, but what about the PC users? I mean at the moment playing games in stereoscopic 3D is the best thing you can do on a 3D-capable display and this is just because there is enough content. Basically almost all 3D games can easily be played in stereo 3D with the help of special software such as Nvidia’s 3D Vision, DDD’s Tridef Ingnition or iZ3D’s Driver and you don’t need games that are specially made for S3D, although that does help. Unfortunately there is no information regarding how and if we are going to be able to use these new 3D-capable HDTVs along with out computers to play games in stereo 3D or watch 3D movies! And considering that at the moment S3D gaming is the major driving force for the adoption of 3D-capable monitors why it seems that the TV manufacturers tend to completely ignore the most important factor?

Regarding videos things are not looking so bright, there is practically very little quality movies and other video content available in a stereoscopic 3D format and that is a serious issue. Hell, there are not even stereoscopic 3D trailers being officially released for movies that are being shown in 3D cinemas, something which is considered promotional material as should get you interested to go see the full movie in a cinema. There are mostly amateur stereo 3D videos that are being freely distributed or very few short demonstrations and that is all, the free content I mean, but even if you are ready to pay you are still out of luck. You’ll have a very hard time finding anything good in the form of stereo 3D movie that you can enjoy on your 3D-capable TV, unless if you want to go for crappy anaglyph videos, but for these you actually don’t need a special TV. Blu-ray 3D is soon going to be available, but at first there aren’t going to be a lot of movies for it. Starting at the summer we’ll probably have just a few titles by the end of the year, so in 2010 it might not be worth the investment for a 3D-ready HDTV, along with a Blu-ray 3D player just for watching 3D movies and there are not much of these. You might consider going way cheaper and just go watch them in a 3D cinema and wait some more, but that is if we are talking about getting a 3D-ready setup just for Blu-ray 3D this year…

And then comes the 3D TV where I suppose everyone is putting their trust into bringing the interest in 3D-capable HDTVs to a mass level, starting with the FIFA World Cup Football Championship 2010 in South Africa that is coincidentally going to start this summer. And there is a lot of trust put in the sports programs being aired in 3D that are supposed to bring crowds of fans of different sports in front of the TV, instead of them going to the stadium. But hey, don’t forget that not everyone likes to watch football or any other sport so that is leaving a big hole and leads to some common mistakes being done when there are global sports events happening – relying too much on the sports fans for pushing products, services and technologies. I’ll talk about the first 3D channels that we are expecting to start being aired very soon in a bit, but when I do that you’ll notice that all of them do plan to have sports events in 3D and that might just not be enough. After all you know the saying – the content is the king, and without the appropriate content 3D might not turn out so big at the start. And yes, I know there are already quite a lot of 3D-capable TVs available, but most of them are actually not been used even once for displaying 3D content and if you ask why, the answer will be very simple – no attractive 3D content being available. Anyway, let me get to the 3D TV channels that are coming later this year and in 2011 that are already announced and expected to be the first and enough with my pessimism…

Sky Channel 3D appears to be the first of the 3D TV channels that we are expecting to see, but this one goes on air in United Kingdom only, sometime in April. And they already did some interesting tests by broadcasting a football match between Arsenal and Manchester United in a few different pubs in London, Manchester, Cardiff and Edinburgh. And this test received quite good feedback from the people that were lucky to be actually watching the game in 3D. Have in mind that the April launch seems to be only related to having the 3D sports content being pushed to a wider number of pubs and not to the general public. And later in the year, Sky 3D will be made available to all Sky+HD customers with a range of content on offer, that will include movies, sport, documentaries and entertainment programs.

DIRECTV (names unknown), backed up by Panasonic should be starting up 3 dedicated 3D channels in the USA. They should be available beginning in June 2010, with customers of the DIRECTV HD service receiving a free software upgrade enabling them to have access to the new 3D channels through their 3D-ready television sets. DIRECTV’s new 3D channels will deliver movies, sports and entertainment content. Also DIRECTV is currently working with AEG/AEG Digital Media, CBS, Fox Sports/FSN, Golden Boy Promotions, HDNet, MTV, NBC Universal and Turner Broadcasting System to develop additional 3D programming that will debut in 2010-2011. At launch, the new DIRECTV HD 3D programming platform will offer a 24/7 3D pay per view channel focused on movies, documentaries and other programming, a 24/7 3D DIRECTV on Demand channel and a free 3D sampler demo channel featuring event programming such as sports, music and other content.

ESPN 3D is another channel that will be offering sports programs starting this summer (in USA), beginning June 11 with the first 2010 FIFA World Cup match South Africa vs. Mexico. The network plans to feature at least 85 live sporting events during its first year, but they’ll probably have other non-live sports content to fill in the holes, but the channel will most likely not be airing content 24/7 at first. Among the planned sports events to be aired live in 3D are up to 25 World Cup matches, the 2011 BCS National Championship Game, college basketball and football and the Summer X Games.

Canal+ 3D will be the first 3D TV channel in France with a launch date planned before Christmas 2010. The new 3D channel will broadcast movies, live events, sports and animation. With the current set-top boxes available to satellite subscribers of Canal+ said to be already compatible with the upcoming 3D broadcast, the only thing that remains is for the viewers to get a hold of a 3D-ready TV set.

3D Pictures is set to launch its own 3D TV channel by the end of this year in Spain. The new channel should be made available to the users via IPTV, satellite, cable, different mobile devices and so on. The channel is currently negotiating with suppliers of content such as sports, movies, concerts, entertainment, documentaries, animation, plays, circus, current affairs and high profile live events.

Discovery 3D (most likely name) by Discovery Communications, partnering with Sony and IMAX is another 3D TV channel competitor expected to launch in 2011 (in USA), but with plans to have content 24/7, unlike some early competitors. The program of the channel will feature high-quality premium content from genres that are most appealing in 3D, including natural history, space, exploration, adventure, engineering, science and technology, motion pictures and children’s programming from Discovery, Sony Pictures Entertainment, IMAX and other third-party providers.

But what happens if you don’t happen to live in USA, UK, Spain, France or Korea for that matter as they seem to be always ahead in terms of new technology – no 3D TV for you at least for now. Of course the major TV networks will soon have their 3D channels available in other countries too with localized subtitles, but that might bring other issues as 2D subtitles will not always look good over all 3D video content. And even then, there is the matter with you having to wear glasses every time you want to watch TV and that is also something that will take some time to getting used to for most of the people that are new to 3D. So in the end there are a lot of unknown factors yet ahead of the wider stereoscopic 3D adoption that everyone is betting on for starting the summer of this year.