dx12 command

anonymous_user_6f0e22f9 · December 13, 2015, 10:09pm

Hi,

im using ue4.10 and when type in command line -DX12 or DX12 it says comand not recognized.

thanks in advance,

Tim_Hobson · December 14, 2015, 3:08pm

Hi ,

This cannot be used as a console command in the editor. You will need to add it as a command line argument. You can see more about this on this page in documentation: Command-Line Arguments in Unreal Engine | Unreal Engine 5.1 Documentation

Thank you!

Tim

anonymous_user_6f0e22f9 · December 14, 2015, 5:09pm

Do i need the dx12 SDK

Tim_Hobson · December 14, 2015, 9:07pm

I’ve not used DX12 yet personally, but all you should need is Windows 10 installed, and a Source or Binary (Launcher) build of the engine. You should not need the SDK to use it in the editor that I’m aware of.

DX12 support in 4.10 is still considered experimental so I would expect some rough edges until it’s moved out of experimental in one of the upcoming major release versions of the engine.

anonymous_user_6f0e22f9 · December 14, 2015, 9:15pm

Hi,

how and where do i need to add this command argument?
and how will the line looks like?

thanks in advance

Tim_Hobson · December 15, 2015, 5:15pm

Right-click on the UE4Editor.exe located in the Engine installation folder location, then select Properties.

You can add the command line in the line with a space between it and the command.

Something like this:

It shouldn’t be anything more complex than this that I’m aware of. I can’t test or verify this or any issues with the DX12 stuff on my machine since I don’t have Win 10 available on my machine currently. I just want to re-iterate that it is experimental, so if you get any crashes please post these in the Answerhub Bug Reports section with any steps to reproduce the issue so we can try and get those fixed up.

anonymous_user_6f0e22f9 · December 15, 2015, 7:43pm

i did it with cmd because it will not boot with changing the properties.
but how do we know it is running in directx12?

Tim_Hobson · December 15, 2015, 9:46pm

Try making a shortcut of your UE4Editor.exe rather than adding to the .exe file directly. In my setup I have all file extensions visible and editable, but this is not a default setting in Windows.

Then open the shortcut using the method before and add -DX12 after the quotes with a single space between them. Then you only need to double-click on the shortcut to open the editor. If you’re GPU is compatible with this it will open without issue, if not you will get a warning message that your GPU is not compatible and to remove the command line argument.

I just tested this on our test Win10 machine. At the moment I’m not aware of a way to know from in the editor other than the project opening without a warning. I’m checking with out QA team to see if there is another way.

anonymous_user_6f0e22f9 · December 15, 2015, 9:52pm

this was the way i opened it and it was running perfect

but how can i be sure that it is running directx 12?

Tim_Hobson · December 15, 2015, 10:37pm

Just spoke with one of the QA team members. Hers’ how you can know if you’re running DX12.

You can open the outputlog, scroll to the beginning, and it will tell you there (screenshot attached)
When launching in -game it should tell you at the top left of the window (D3D12 or DX12)

This is a log from a DX11 machine, but this should be listed as DX12 when chosen.

tomofnz · May 19, 2019, 5:47am

You can roll your mouse over your project title in the top-right of the editor and it displays ‘Graphics RHI : Direct##’

You can also set in Project Preferences the RHI default to Directx12

For me, I’m getting a wonky flickering when my project is in Directx12 (this covers at an epileptic rate the entire editor and any extra slate windows that are also open):