3D experience

[carambaspombas]

Hello guys, I'm buying a display with 3d ready for passive 3d, and I'm looking forward to use passive 3D, but, I'm buying a new pc too... and that's the proble, I just can't decide which GPU to chose:

Geforce Gtx 680
or
AMD HD 7950

I now that gtx 680 it's better almost all the times, but I have to ask anyways... and another question, can I use this Nvidia Geforce with Tridef to get passive 3D? or the passive 3D only works with Tridef combining with AMD? If it doesn't work with tridef for passive 3D, how is it possible to play passive 3D with the nvidia...

Thanks already, waiting for opinions...

 

[chugot9218]

I don't think you need a beastly GPU for passive 3d, it is not even a full 1080p image...

 

[carambaspombas]

But I'm not doubting the "beastness" of these two xD, I just don't understand 3D and their packs with the nvidia... Just because nVidia has this "3D vision" that is active 3D, does not mean it won't work with tridef (passive 3D) right?

 

[chugot9218]

They probably only advertise it as supporting Active 3d because that is the latest tech, basically if it supports active 3d I would assume it must be capable of passive 3d. I believe a decent amount of passive 3d technology is software side, where they may have hardware components that are working to produce the active 3d. Active 3d basically puts out 2 full 1080p images that combine to provide you a 3d 1080p image using the active shutter glasses. Passive 3d uses a single 1080p image in combination with polarized glasses to produce a 3d image that cannot be full 1080p quality.

 

[djscribbles]

I'm inclined to disagree chugot. Even in a side by side (or interleaved, as I believe passive 3d is done) requires a scene to be rendered from 2 view points, even at a split resolution this requires more processing power. Rendering 2 scenes in one 1080p window requires more GPU power than rendering a single scene in a 1080p window.

In general, AMD tends to play better with Tridef; however Nvidia does work with it as well. For passive 3d (again I assume it's interleaved, never looked into passive 3d much), I don't think the GPU choice would make much difference.

I would suggest considering a 7970 GHz Edition, it's AMDs answer to the 680 (The 7970GE beats the 680 in most benchmarks I believe), and it runs a little cheaper I think. This way you can be sure to avoid any incompatabilties that may result from nvidia (who prefer you to use their 3d solution), and still have good performance.

I personally have a frame-sequential 3d setup on an AMD 7870, and find that it's a little lacking in gpu power for high detail levels in 3d; I'm hoping to upgrade to a 7970 GE soon

 

[chugot9218]

You may be correct scribbles, I like having people calmly and reasonably present differences in opinion/interpretation and you definitely do that.

The way I interpret the Passive 3d technology is that the display is not actually outputting 2 separate 1080p images, it simply has a filter on the screen that displays a duplicate image offset from the original, so the GPU would still only be producing 1 1080p image. I may be interpreting it incorrectly though.

 

[bystander]

I believe you can get passive systems to work with Nvidia by using 3DTV play.

http://www.nvidia.com/object/3dtv-play-system-requirements.html

I don't know what works best. I do know that active systems on Nvidia work with Tridef and 3D Vision. From the best I can tell, Tridef will work with Nvidia's stereoscopic drivers. Besides the much more complex software of Tridef, I can't tell much difference between the two.

 

[bystander]

You may be correct scribbles, I like having people calmly and reasonably present differences in opinion/interpretation and you definitely do that.

The way I interpret the Passive 3d technology is that the display is not actually outputting 2 separate 1080p images, it simply has a filter on the screen that displays a duplicate image offset from the original, so the GPU would still only be producing 1 1080p image. I may be interpreting it incorrectly though.

That's not quite true. This might be closer to true when using these 2D to 3D conversion TV's, but Stereoscopic 3D will give the graphics card 2 separate view points, and renders the images 2 times, one for each eye, as if your point of view is 4 inches a part like our eyes are accustomed to. Shifting the view point does more than just move the image 4 inches to the side and it has more affect on objects closer to you than ones at a distance. The good news is they share physics and AI information, so that doesn't have to be done twice, but the rendering is.

 

[chugot9218]

Well, I am pretty sure both active and passive are stereoscopic, but I am fairly sure it is the active 3d that renders 2 images, I still think passive simply uses filters.

I am however mainly researching on Wikipedia, but I did look elsewhere. Here is my source if anyone can enlighten me on where I am getting it wrong. http://en.wikipedia.org/wiki/Stereoscopy#Active

I believe this article may support my thoughts on active vs passive: http://reviews.cnet.com/8301-33199_7-57437344-221/active-3d-vs-passive-3d-whats-better/

The TV has to have 120hz refresh rate in order to provide 60fps for each eye, allowing for 2 seperate 1080p images.

 

[djscribbles]

You may be correct scribbles, I like having people calmly and reasonably present differences in opinion/interpretation and you definitely do that.

The way I interpret the Passive 3d technology is that the display is not actually outputting 2 separate 1080p images, it simply has a filter on the screen that displays a duplicate image offset from the original, so the GPU would still only be producing 1 1080p image. I may be interpreting it incorrectly though.

The way I believe a passive system works is that alternating columns of pixels are polarized for each eye, so (as an example) the left eye see odd columns and the right eye sees even columns (and the glasses filter out the opposing eye's image). So, the Tridef software will inject itself into the game so that it draws two scenes, each at half the width of a normal 1080p image, and interleave the columns for the monitor.

There is no way to achieve a real 3d effect without rendering a scene twice; some virtual 3d methods will extrapolate an alternate viewpoint from the original, and present it (via a 2d to 3d conversion), but I don't believe that any products that allow this method block you from doing real 3d through Tridef type solutions (it's more of a bonus feature to 3d-ify non 3d content).

(Here's a post from bystander about it too: http://www.tomshardware.com/forum/64507-3-shutter-glasses-passive-glasses )

edit: Regarding the Cnet article, I think I see where you got the impression that passive isn't actually 3d. It states that without the glasses, the image appears normally, which is true; but if you put an image on the screen that has two interleaved 960x1080 perspectives of the scene, it will look like a mess (but it is displaying exactly what is being rendered), because each eye sees both the left eye pixels and right eye pixels; if you put on the glasses, blocking out the opposing eye's pixels, you see the 3d picture. If you are displaying a normal 2d image, having the glasses off causes the monitor to look like a normal 2d monitor.

A passive monitor is just like a normal monitor without 3d glasses (the point the article tries to make), but will show 2 different 960x1080 images to each eye with glasses on (a point the article alludes to).

 

[bystander]

Well, I am pretty sure both active and passive are stereoscopic, but I am fairly sure it is the active 3d that renders 2 images, I still think passive simply uses filters.

I am however mainly researching on Wikipedia, but I did look elsewhere. Here is my source if anyone can enlighten me on where I am getting it wrong. http://en.wikipedia.org/wiki/Stereoscopy#Active

I believe this article may support my thoughts on active vs passive: http://reviews.cnet.com/8301-33199_7-57437344-221/active-3d-vs-passive-3d-whats-better/

The TV has to have 120hz refresh rate in order to provide 60fps for each eye, allowing for 2 seperate 1080p images.

The only filter systems they mentioned was when using anaglyph systems. They may also have used the term for how the glasses filter out the wrong image for each eye. That does not change that each image is independently rendered for each eye.

 

[chugot9218]

Yes, but my point is, by polarizing opposite odd/even sets of pixels, it is still only working with 1 1080p image, it simply renders half the pixels in a different manner than the others. My understanding is that active works by rendering a full 1080p image with the pixels one way, and another full 1080p image with the pixels the other way, on the same screen, and alternating them at double the refresh rate of a standard image. So 60+ FPS for each image for each eye.

 

[bystander]

Yes, but my point is, by polarizing opposite odd/even sets of pixels, it is still only working with 1 1080p image, it simply renders half the pixels in a different manner than the others. My understanding is that active works by rendering a full 1080p image with the pixels one way, and another full 1080p image with the pixels the other way, on the same screen, and alternating them at double the refresh rate of a standard image. So 60+ FPS for each image for each eye.

Again, read what was written in the article, there is nothing writing to support this claim, but there is this:

Stereoscope and stereographic cards
Main article: Stereoscope

The stereoscope is essentially an instrument in which two photographs of the same object, taken from slightly different angles, are simultaneously presented, one to each eye. A simple stereoscope is limited in the size of the image that may be used. A more complex stereoscope uses a pair of horizontal periscope-like devices, allowing the use of larger images that can present more detailed information in a wider field of view.

Both passive and active systems are Stereoscopic. The way they are presented is the only thing that changes. Active shutter systems blacks out every other image for each eye to present the correct frame for each eye, and passive systems use a polarized light filter to block out every other row or column to present the image to the user.

 

[djscribbles]

Yes, but my point is, by polarizing opposite odd/even sets of pixels, it is still only working with 1 1080p image, it simply renders half the pixels in a different manner than the others. My understanding is that active works by rendering a full 1080p image with the pixels one way, and another full 1080p image with the pixels the other way, on the same screen, and alternating them at double the refresh rate of a standard image. So 60+ FPS for each image for each eye.

Ahh, I see. Yes there is a single 1080p image. But in order to generate depth, you still have to render a scene from two view points, each at 960x1080; because shaders, lighting, textures, anti-aliasing etc all are applied after you render the geometry in the scene, when you shift your perspective matrix (for the alternate viewpoint), you have to recompute much of the hard stuff, so it is like drawing everything twice at half resolution.

 

[chugot9218]

LoL, well maybe we aren't on the same page here. I understood from the beginning they are both Stereoscopic, my whole point was that creating the image for a Passive 3D system is less intensive than for Active, because, as I read above, passive presents 2 960x1080 images interleaved together, resulting an a final image that is not truly 1080p. Instead of interleaving pixels, Active creates two seperate images and alternates them at double the normal rate, thus a true 1080p 3D image. I think at this point either I/We no longer know what we are disagreeing on lol.

Re-reading some of the above points I have some clarification. I see that passive will still require 2 images to be rendered but it still remains that they are not two full 1080p images, they are half the resolution, and thus, an active tv rendering 2 full 1080p images is going to require more GPU power than the passive. Is this a fair assessment?

 

[bystander]

You may find a lot if not most passive systems go with 1920x590 resolutions, but either way, every other line is for one eye, and the other eye is for the other. I think I mistakenly wrote the split the wrong direction before. The end result is still the same.

 

[bystander]

LoL, well maybe we aren't on the same page here. I understood from the beginning they are both Stereoscopic, my whole point was that creating the image for a Passive 3D system is less intensive than for Active, because, as I read above, passive presents 2 960x1080 images interleaved together, resulting an a final image that is not truly 1080p. Instead of interleaving pixels, Active creates two seperate images and alternates them at double the normal rate, thus a true 1080p 3D image. I think at this point either I/We no longer know what we are disagreeing on lol.

That part is correct, or at least correct to the best of my knowledge. Your idea that they just shifted a single image and not render two separate images, is the part we disagreed with.

 

[chugot9218]

Ahh, okay, the way I interpreted the filter part is that instead of relying on processing to produce the second image from a different perspective (which I understand better now), it simply had a filter that altered the perspective to some default/standard to produce the second image. It makes perfect sense to me now that there would be more to account for with the change of perspective that would necessitate some additional processing, to produce higher quality 3d images.

 

[carambaspombas]

Best answer selected by carambaspombas.

 

[carambaspombas]

Thanks all of you guys, now I'll have new ideas