I see that this is now supposed to be supported in UE5.3, but I don’t know how you change from building x64 to ARM64
Interesting question. I suspect you need to set some environment variables, have the correct toolchain(s) installed, set -specifiedarchitecture=arm64 and maybe more steps, but it doesn’t seem to be (well) documented right now.
On MacOS with an M2 Mac, I switch from Intel to Arm64 builds like this:
By default, the shell is arm64, so I just call RunUAT:
For x64, I need to switch my shell:
$env /usr/bin/arch -x86_64 /bin/zsh --login
Set 2 environment variables:
export ARCHS=x86_64
export VALID_ARCHS=x86_64
Then call RunUAT with the -specifiedarchitecture option:
RunUAT.sh BuildCookRun -targetPlatform=Mac -specifiedarchitecture=x86_64
As for the ‘and more’ you may need to build UE 5.3 from source for arm64 to get the right libraries/tools and/or run the engine on an arm64 Windows PC and/or other stuff I cannot even guess. I couldn’t figure this out in 45 minutes, but if it is important to you, I’m sure you’ll get there!
Fairly easy to get it building in VS. I copied the dotnet.exe from vs to engine\binaries\thirdparty.…\win-arm64 folder.
Builds everything fine. except No reflection data is picked up.
My system only has 500 gig hd so I cannot build from source code.
If you get it working let me know what you did.