Current state and solutions for OpenGL over Windows Remote [closed] - opengl

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OpenGL and Windows Remote don't play along nicely.
Solutions for this are dependent on the use case and answers are fragmented across the vast depths of the net.
This is a write-up I wish existed when I started researching this, both for coders and non-coders.
Problem:
A RDP session of Windows does not expose the graphics card, at least not directly. For instance you cannot change the desktop resolution and GraphicsCard drivers usually just disable their setting menus. Starting a OpenGL context higher than v1.1 fails because of this. The, especially in support IRCs, often suggested "Don't use WindowsRemote" is unfortunately not an option for many. In many corporate environments Windows Remote is a constantly used tool and an app has to work there as well.
Non-Coder workarounds
You can start the OpenGL program, allowing it to see the graphics card, create an opengl context and then connect via WindowsRemote. This always works, as Windows remote just transfers the window content. This can be accomplished by:
A batch script, that closes the session and starts the program, allowing you to connect to the program already running. (Source)
Using VNC or other to remote into the machine, start the program and then switch to Windows Remote. (Simple VNC programm, also with a portable client)
Coder workarounds
(Only for OpenGL ES)Translate OpenGL to DirectX. DirectX works under Windows Remote flawselly and even has a Software rendering fallback built into DX11 if something fails.
Use the ANGLE Project to do this at run-time. This is what QT officially suggests you do and how Chrome and Firefox implement WebGL. (Source)
Switch to software rendering as a fall back. Some CAD software like 3dsMax does this for instance:
Under SDL2 you can use SDL_CreateSoftwareRenderer (Source)
Under GLFW version 3.3 will release OSMesa (Mesa's off screen rendering), in the mean time you can build the Github version with -DGLFW_USE_OSMESA=TRUE, but I personally still struggle to get that running (Source)
Directly use Mesa's LLVM pipe for a fast OpenGL implementation. (Source)
Misc:
Use OpenGL 1.1: Windows has a built in implementation of OpenGL 1.1 and
earlier. Some game engines have a built in fall back to this and thus
work under Windows Remote.
Apparently there is a middle-ware, that allows for even OpenGL 4 over Windows Remote, but it's part of a bigger package and is a commercial solution. (Source)
Any other solutions or corrections are greatly appreciated.
[10] Nvidia -> https://www.khronos.org/news/permalink/nvidia-provides-opengl-accelerated-remote-desktop-for-geforce-5e88fc2035e342.98417181

Answer 1

According to this article it seems that now RDP handles newer versions of Direct3D and OpenGL on Windows 10 and Windows Server 2016, but by default it is disabled by Group Policy.
I suppose that for performance reasons, using a hardware graphics card is disabled, and RDP uses a software-emulated graphics card driver that provides only some baseline features.
I stumbled upon this problem when trying to run Ultimaker CURA over standard Remote Desktop from a Windows 10 client to a Windows 10 host. Cura shouted "cannot initialize OpenGL 2.0 context". I also noticed that Repetier Host's "preview" window runs terribly slow, and Repetier detects only an OpenGL 1.1 card. Pretty much fits the "only baseline features" description.
By running gpedit.msc then navigating to
Local Computer Policy\Computer Configuration\Administrative Templates\Windows Components\Remote Desktop Services\Remote Desktop Session Host\Remote Session Environment
and changing the value of
Use hardware graphics adapters for all Remote Desktop Services sessions
I was able to successfully run Ultimaker CURA via with no issues, and Repetier-Host now displays OpenGL 4.6, and everything finally runs fast as it should.
Note from genpfault:
As usual, this Policy is kept in the HKLM registry group in
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services
Set REG_DWORD:bEnumerateHWBeforeSW to 1 to turn ON using GPUs in RDP.

Answer 2

OpenGL works great by RDP with professional Nvidia cards without anything like virtual machines and RemoteFX. For Quadro (Quadro 4000 tested) you need driver 377.xx. For M60 you can use the same driver. If you want to use last driver with M60, you have to change the driver mode to WDDM mode (see c:\Program Files\NVIDIA Corporation\NVSMI\nvidia-smi.1.pdf). It is possible that there are some problems with licensing in this last case.

Answer 3

Some people recommend using "tscon.exe" if you can: https://stackoverflow.com/a/45723167/32453 or using a scheduler to do it on native hardware: https://stackoverflow.com/a/41839102/32453 or creating a group policy:
https://community.esri.com/thread/225251-enabling-gpu-rendering-on-windows-server-2016-windows-10-rdp
maybe copy opengl32.dll (or opengl64.dll) to your executable's dir: https://blender.stackexchange.com/a/73014 and newer version of the dll: https://fdossena.com/?p=mesa/index.frag

Answer 4

Remote Desktop and OpenGL does not play very well. When you connect to a Windows box the OpenGL Driver is unloaded and you end up with software emulation of OpenGL.
When you disconnect from the Windows box the OpenGL driver is not reloaded. This causes issues when you are running tests on the machine as you have to physically login to the machine to reset the drivers.
The solution I ended up using was to:
Disable Remote Desktop.
Delete all other software for remote desktop access. Because if it's used for logging in remotely the current set of drivers loaded may be messed up.
Install NoMachine
NoMachine is my personal favourite (when it does not play up) for a number of reasons:
Hardware acceleration of compression (video of desktop).
Works on Windows and Linux.
Works well on low-bandwidth connections especially if the client and server have the necessary hardware for compression of the data stream.
On Linux you get your desktop as you last left it when you were sitting in front of the machine.
On Windows it does not affect OpenGL.
currently free for personal and commercial use. Do check the licence in case it's changed.
When NoMachine plays up it hogs the CPU but this happens rarely. It is however in active development
Others to consider:
TurboVNC
TightVNC
TeamViewer - only free for personal use.