Graphics bug with HI-Res/4K monitor

[bbinnard]

My Win10-64 system has 2 monitors: Primary is an LG 27" @ 3840x2160 resolution, and the secondary is a Dell 24" @ 1920x1080 resolution. Both are driven by an nVidia GTX750 using the current nVidia video driver Ver. 384.94. S3D 4.0.0 has graphics related bug when running on the 4K monitor:

On my Primary monitor the Print Preview screen displays incorrectly. Photo 1

shows how it looks on my Primary, regardless of how I resize the window. Interestingly enough, the display becomes OK if I drag it onto the Secondary monitor. But if I then drag it back onto the primary it reverts to the incorrect display. Another interesting thing is that is if I drag one of the edges of the window to resize it, as the window changes size the display fixes itself momentarily, but reverts to incorrect as soon as I stop resizing. This happens only on the Primary monitor; resizing the window works OK on the secondary.

On the Primary, when I resize the S3D window and preview expands to fill the full window, the size of my 3D object gets larger, but the image of the speed bar tower does not change.

I've tried restarting S3D on the Secondary (looks good), but get incorrect results when dragging onto Primary. I get consistently incorrect display on Primary regardless of whether it starts full screen or windowed. Minimizing and returning to either full screen or windowed does not help either.

Using legacy graphics has no effect on this problem.

[wirlybird]

This is could be a driver issue or it could be with the port you are connecting to on the card. For 4K 60Hz you really need to use the display port or HDMI 2.0.

You can try reducing the refresh to something around 30 and see, and/or reduce the resolution down to 2560X1440.

I really doubt it is S3D.

[bbinnard]

As I said, my display driver is the most current WHQD one direct from nVidia. Both monitors are driven by HDMI connections. The refresh rate on the 4K monitor is 30Hz, 60HZ on the Secondary.

Reducing the resolution to 2560 x 1600 fixes the problem on the 4K, but it comes back when I revert to the default 3840 x 2160. This makes me believe there is something in S3D that is resolution sensitive.

[wirlybird]

Reducing the res is a know issue/fix. I believe the HDMI's are ver 1.4 on that card and probably cables also and that is the issue it won't necessarily support the higher res and or refresh.
I think you'll need a display port or HDMI 2 for full res and refresh.

[bbinnard]

The issue of HDMI 2.0 versus 1.4 is an interesting one. But I wonder if that would really fix the problem considering the initial display when the part is first loaded is fine.

Also, when I have the Preview window half/half on each monitor the half on the 4K screen looks fine. But when I move more than half of it onto the 4K screen it reverts to the bugged version.

[jfkansas]

This is could be a driver issue or it could be with the port you are connecting to on the card. For 4K 60Hz you really need to use the display port or HDMI 2.0.

You can try reducing the refresh to something around 30 and see, and/or reduce the resolution down to 2560X1440.

I really doubt it is S3D.

My laptop has a 4k display and it has always been a little wonky with S3d. It definitely is an issue.

[Barafu]

I have the same bug too. It is a regression in 4.0 because it was always fine before that.

Problem
The print preview takes only 1/4 of the windows space reserved for it. The main view (were parts arrangement happens) looks fine, only the print preview is affected. Print preview can still be rotated and used normally. I think pribt preview should occupy the same space as main view.
System
I use Arch Linux, Nvidia card(prop. drivers), 4K monitor. Cinnamon DE, if it matters.
Notes
* If I resize the window with print preview on, then, while I am dragging it, the preview becomes normal size, occupying all available screen. However, as soon as I stop moving the mouse, preview becomes 1/4 of the size again.
* Switching graphics to legacy mode does not change anything visibly.
* Bug does not exist in version 3.1.1 on the same machine at the same time

P.S. Considering notes above, I am sure it has nothing to do with hardware or its drivers.

[wirlybird]

The issue of HDMI 2.0 versus 1.4 is an interesting one. But I wonder if that would really fix the problem considering the initial display when the part is first loaded is fine.

Also, when I have the Preview window half/half on each monitor the half on the 4K screen looks fine. But when I move more than half of it onto the 4K screen it reverts to the bugged version.

Yea it is. You can try something. You mentioned that it worked ok at the reduced resolution. Try reducing the refresh to 24Hz and run the res back up and see what happens. I think it may be that HDMI 1.4 seems to support up to 24-30Hz for 4K.

I would run some test. How high can you get the res? Does lowering the refresh help with a higher res?

Here is a little blurb on specs:
"A single dual-link DVI connection can deliver up to 2560 × 1600 at 60 Hz. Achieving 4K at 60Hz requires two dual-link DVI cables, or DisplayPort 1.2 or HDMI 2.0."

[bbinnard]

That is an interesting suggestion wirly, and not something I had considered doing. I tried both 24 and 23Hz, which are the 2 lowest values the nVidia control panel offers, and there was no change in results. Plus, none of the other slicers I use (Craftware and Slic3r) or any other piece of software has this same problem.

I make extensive use of the print preview screen since I typically revise the design of a part 4 - 10 times before actually printing, and I am disinclined to lower my resolution since i bought the 4K monitor specifically for that purpose.

[wirlybird]

Yea, I understand that!
I have a couple 30" non 4K but if I don't use the dual link DVI cable my resolution is restricted to a lower one than the card or monitor is capable of.