[Jiricbeng]

Hi, when connecting via remote desktop, CFX screen (Pre and Post), where the model is, is black. I tried different settings of RDP connection but did not help. Fluent works fine as well as other Workbench utilities. I also tried CFX -> properties -> compatibility -> change high DPI settings -> override high DPI scaling behaviour to System (enhanced) as this was needed to set for Workbench and Fluent due to graphical issues. But this was not the problem in CFX.


Graphic card is dedicated NVIDIA GeForce GT 640.



Any ideas are welcome.

[urosgrivc]

I have the same problem.

Even more interesting thing is that If one would get on the computer via VNC or any other connection than remote desktop this problem diapers and you can open CFX pre and post without black screen.
Then if you cancel the VNC connection and acces it via remote desktop it works normally, till you close it and try to open again, then it is black again.

So I think it is not even Remote desktop problem it must be just something when turning on CFX pre and post only via remote desktop.

This problems were not present in the ansys18 version, but are present in 2019.

Any ideas?

[Jiricbeng]

Yes, exactly. I have the same experience. I searched the issue on the internet and it seems it is problem of "OPENGL". An interesting point is that if you set the system variable to QT_OPENGL = desktop, the CFX Pre can be opened via RD without black screen, but CFD Post does not even start. I have not found a solution yet, only opening the CFX by VNC or Teamviewer and then using RDP.


An even more interesting fact is, that if you switch CFX and have the black screen and then you physically go to login on the PC, the black screen is still presented also on the PC. Obviously, the black screen issue propagates back to the PC screen.

[ghorrocks]

There used to be an option in CFX-Pre and Post to start it is MESA graphics mode which means it did not use OpenGL. Have a look in the documentation and see if this option still exists.

The problem is usually OpenGL does not render to the remote desktop application. Laso have a look at the remote desktop options, and see what controls you have in rendering OpenGL.

[Freeman]

I am experiencing the same problem.

I set the QT_OPENGL=desktop variable in the PC where I run Remote Desktop and the black screen is still there (CFX Post).

By the way, in which PC the environment variable has to be set?

[AtoHM]

We experienced the same behavior with my home oc running win10 and the work station on win7. We upgraded the ws to win10 and now I can use CFX in whole via remote. I don't know what causes the issue in the first place, but both computers running the same OS helped for me. We have the latest CFX release.

[Freeman]

Originally Posted by AtoHM

We experienced the same behavior with my home oc running win10 and the work station on win7. We upgraded the ws to win10 and now I can use CFX in whole via remote. I don't know what causes the issue in the first place, but both computers running the same OS helped for me. We have the latest CFX release.

I am using Win10 in both machines, ANSYS 2019 R2.

[AtoHM]

We switched to cfx 2020R1 recently. Had the same issue as you with cfx19, but at that time there was also the version mismatch of the computers, so I can't tell if that would have fixed it for cfx19.

[ghorrocks]

I suspect you will find it has nothing to do with the version of ANSYS/CFX. It is all about the rendering of OpenGL applications and how it is handled in remote desktop. Do a google search on OpenGL and remote desktop and you will find lots of stuff on it.

[Gert-Jan]

On the RDP machine, set an environment variable:

Variable Name: QT_OPENGL
Value: desktop

You can do it as a User Environment variable. Then it only works for you.

If you are allowed to do it, set it as a system environment variable and it will work for anyone.

[urosgrivc]

Uuu nice It works thank you so much

[freddy_fang]

Originally Posted by Gert-Jan

On the RDP machine, set an environment variable:

Variable Name: QT_OPENGL
Value: desktop

You can do it as a User Environment variable. Then it only works for you.

If you are allowed to do it, set it as a system environment variable and it will work for anyone.

It worked! Thx so much!

[Darko]

Dear All,
Just to add to the comments above.
If you have set the variables as mentioned before and still get the black docked view within CFD-post you can use this article and download a developer's file that runs the opengl upon starting a remote desktop.
go to:
https://developer.nvidia.com/designworks
and look for:
Accelerate Windows Remote Desktop
there is a file for windows but be aware you will be asked to sign up!

Regards,

Chris

[aero_head]

Hello Everyone,

I had the same issue, but there is a Nvidia RDP exe to install from their website to use CFX over RDP on Win10 with GeForce GTX graphics cards.

Go to https://developer.nvidia.com/nvidia-opengl-rdp (you need to register). Then the exe to install is: nvidiaopenglrdp.exe

Hope this helps.

[UjjawalArya]

Thanks for this suggestion! It worked as expected!
For people who are trying to figure out how to add these environment variables:
ThisPC->Right_click->Properties->Remote_Settings->Advanced->Environment_Variables->New

[aiden_1995]

hi guys
i have the same problem but it doesn't solve with this method can anybody help me with that?

[Gert-Jan]

I came across this following link which might be applicable for your situation

Resolved: Problem using Remote Desktop MobaXterm (black screen)

[aiden_1995]

thanks ever so much

[micro11sl]

Thank you so much! Changed env variables. It works!