USD import at runtime in UE5.6

Development Programming & Scripting
,
1

Hi there, I have an issue importing USD files at runtime with the SetRootLayer function from the UsdStageActor. I have an actor that on beginPlay spawns a UsdStageActor and gives it a .usdz file (all done in Blueprints). At runtime in the editor, this stage editor has the correct Mesh. However, when I build the project, no USD files are loaded anymore. The Unreal Documentation says to add

GlobalDefinitions.Add("FORCE_ANSI_ALLOCATOR=1");

to my Project.Target.cs. https://dev.epicgames.com/documentation/unreal-engine/universal-scene-description-in-unreal-engine#:~:text=To%20enable%20the%20USD%20importer%20at%20runtime%2C%20add%20the%20following%20line%20to%20your%20Project.Target.cs%20file%20located%20in%20the%20UE_(version)%5CEngine%5CSource%20folder%2C%20where%20Project%20is%20your%20project%20name%3A

To do this, I had to add

bOverrideBuildEnvironment = true;

to my ProjectName.Target.cs file because I am not using a Source Build of Unreal Engine. In this thread UE4.27 Runtime USD Import the solution is to build the Engine yourself. Is this still required for USD import at runtime in UE5.6?

After adding that, I get this build error:

Target 'ProjectName' contains a definition for 'FORCE_ANSI_ALLOCATOR' allocator define. It conflicts with the new allocator type declaration via UBT. Please use 'StaticAllocator = StaticAllocatorType.Ansi;' in your *.Target.cs instead

Doing that, I now get a runtimeError:

LogUsd: Error: The USD SDK is disabled because the executable is not forcing the ansi C allocator (you need to set 'FORCE_ANSI_ALLOCATOR=1' as a global definition on your project *.Target.cs file). Read the comments at the end of UnrealUSDWrapper.Build.cs for more details.

That comment says, to use USD import, you need to add these lines to your Target.cs:

StaticAllocator = StaticAllocatorType.Ansi;
GlobalDefinitions.Add("UE_USE_MALLOC_FILL_BYTES=0");

so I added the second line as well, but the error message persists.

To clarify: my issue is the Engine throwing the USD SKD disabled error.
Is there any solution other than building Unreal Engine from Source (and removing the overrideBuildEnvironment line)?

Thanks in advance!