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Issue with Nvidia Vision 2

Aug 4, 2015 at 1:36 AM
Just got started with a new system and 3d rig:
  • I7-4790k CPU
  • 16 GB RAM
  • Windows 8.1
  • GTX 970 GPU
  • AOC G2460PG Monitor (1080p, 144 Hz, G-Sync)
  • Nvidia 3d Vision 2 Wireless Glasses Kit
The monitor and graphics card are working great. I've successfully run with G-Sync. I've also gone through all the 3d Glasses setup. I can do the examples and the slide show. I've done Borderlands Prequel, Hard Reset, and Dear Esther with 3d shutter glasses. Everything is working fine. So of course I wanted to try out 3d with Second Life.

I installed your viewer and started it up in full-screen with the 3d shutter glasses selected. I clicked the "Toggle 3d" button and the light on the emitter glowed. I got the double images that showed me things were working. The problem is when I put on the glasses, I could still see both images with each eye. Hmmm... Something isn't right.

I checked my monitor and it says it is displaying a 144 Hz signal. That's not right. The glasses are supposed to work at 120 Hz. Maybe that's why they're not synced up right. Even after I selected "Set Output to 120 Hz" in the CtrlAltStudio Viewer, the monitor is still at 144 Hz. That seems to be the problem.

I tried it in windows mode and even tried to force the monitor to only run at 120 Hz in the Nvidia control panel, but to no avail. I can't get 3d mode to engage in a window (probably by design) and I can't get out of 144 Hz when in full screen.

So... is there a tweak to the code that has to be made for 144 Hz monitors? Something that would force the monitor to display at 120 Hz so the glasses can sync up properly?

Thanks,
Tantari
Aug 4, 2015 at 4:59 AM

Hi Tantari,

You may need to run your graphics card and monitor at 120Hz in order for stereoscopic 3D to work.

The “Set Output to 120Hz” option was added as a convenience for people who want to normally run at 60Hz and only switch to 120Hz when running the viewer. This option is not guaranteed to work, and perhaps it isn’t working for you running at 144Hz.

David

Aug 5, 2015 at 12:52 AM
When enabling the 3d Vision in the Nvidia driver, it automatically forces the monitor into 120 Hz mode. I've verified that by using the monitor's display. I've also gone into the "Change Resolution" tab and forced the monitor to 120 Hz there also. But as soon as I go full-screen with the CtrlAtlStudio viewer, it immediately changes the refresh rate to 144 Hz. This happens whether I use the "Set Output to 120 Hz" option in the viewer or not. And it stays at 144 Hz until I close the program and go back to the desktop.

Does anyone have any suggestions for how to force 120 Hz in the CtrlAltStudio Viewer? As mentioned previously, I have the 3d shutter glasses working great at 120 Hz in multiple games.

Thanks,
Tantari
Aug 5, 2015 at 4:20 AM
If you disable the 120Hz option in the viewer, then restart the viewer, there's nothing in the viewer code that sets the display rate. So if you have your GPU and monitor set to 120Hz before starting the viewer it should stay at 120Hz! ... So if it's switching to 144Hz then the driver must be deciding that 144Hz would be better. The viewer code is fairly simple in that it just creates the two eye images in two OpenGL buffers and leaves it to the NVIDIA 3D Vision driver to display.

In the GeForce forums - https://forums.geforce.com - it appears that 3D Vision should work at 144Hz (if the monitor is certified to run 3D Vision at that rate). So maybe you can run 3D Vision at 144Hz?
Aug 6, 2015 at 12:05 AM
I did some research. It appears that the glasses are designed to work at 120 Hz. I can't find any official documentation that says they work at any other frequency.

http://www.nvidia.com/object/product-geforce-3d-vision2-wireless-glasses-kit-us.html
https://forums.geforce.com/default/topic/526222/144hz-3d-vision-support/

I've also noticed that on every other 3d game I've tried, the monitor goes right to 120 Hz and stays there. The game itself seems to think that it is running at 60 Hz, as reported by the Steam on-screen FPS meter.

I guess I'm at a bit of a dead end here. Thanks for trying. If anyone finds anything out about this, I'd be happy to test it. :)

Thanks,
Tantari
Aug 23, 2015 at 6:29 PM
I figured out how to make it work. The secret is that you need to set your monitor to the base rate, and then the Nvidia Vision tries to double up, but caps out at the max refresh rate of your monitor. So if you have a 120 Hz monitor, it all works out every time. If you don't, it won't.

120 hz doubled = 240 Hz. Capped to 120 Hz (for a 120 Hz monitor) Works!
120 hz doubled = 240 Hz. Capped to 144 Hz (for a 144 Hz monitor) Doesn't work because glasses sync at 120 Hz

But if you set your monitor to an initial refresh of 60 Hz, it all works out

60 hz doubled = 120 hz. Doesn't need to be capped. Stays at 120 Hz (for a 144 hz monitor) Works!

That's the secret. In the Nvidia control panel, I made sure to enable the "stereoscopic 3D" like I would for any other game. But then under Display -> Change Resolution, I set the monitor refresh rate to 60 Hz.

As soon as I start the CtrlAltStudio viewer with 3D already enabled, it kicks the monitor up to 120 Hz 3d. (3d must be enabled in the viewer before you start. If not, enable it, quit the viewer, then start it right up again.)

If I were to recommend something to be updated in the viewer, it'd be a check box to "force 60 Hz). The OpenGL application thinks it is at 60 Hz. Indeed it is. It's showing both buffers 60 times a second. Behind the scenes, it seems that Nvidia is doubling the refresh rate. If not, just update the documents somewhere to recommend this to the next person. :)

Thank you for making a cool viewer. Seeing all the avatars in 3D is pretty cool. :)
Tantari
Marked as answer by TantariKim on 8/23/2015 at 10:29 AM
Aug 24, 2015 at 12:56 AM
Thanks very much for the info on how you managed to get it stereoscopic 3D working with your 144Hz monitor!

It seems that the behaviour of the NVIDIA 3D Vision driver has changed. I have a 120Hz monitor built into my laptop and it used to be that I had to set the graphics to 120Hz in order for 3D Vision to work (hence the "force 120Hz" viewer option). But now I can see stereoscopic 3D both when I start up with the graphics set to 60Hz and when I start up with the monitor set to 120Hz. (Note: I don't have separate graphics and monitor display rate settings like you have if you have an external monitor.)

I've added a paragraph to the instructions on the Web site about possibly needing to set things to 60Hz if using a 144Hz monitor - http://ctrlaltstudio.com/viewer.

Thanks again for the tip.