Unity as a Library DLL with version 6

Unity Engine
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1

I’m currently working on using Unity as a Library and embedding it in a WPF project, but have run into inconsistent behavior between versions. The goal is to embed it with the existing project, and not call it as a separate process. The initial testing performed with Unity 2023.3.3f1 works find, with both the DLL and running unity as a separate process. When I upgraded to Unity 6 (6000.024f1 and 6000.027f1) the separate process configuration still worked, but the DLL implementation is currently throwing an access violation after calling UnityMain(). I added in additional symbols and the last item on the call stack that’s now showing up is UnityPlayer.dll!FixupD3D12SDKPath().

  • Other approach I’ve tried include:
  • Building Unity with .Net Framework
  • Building Unity with .Net Standard
  • Building Il2cpp (this gives a different error so I’m focusing on the .Net builds)
  • Forcing D3D11 (-force-d3d11) since the call stack gives the impression that there may be an issue with D3D12.
  • Built unity with only D3D11 support
  • Compiling WPF with VS2022 (Originally used VS2019)
  • Various permutations of the DllImport

Did something change between 2023 and version 6 which would impact Unity as a Library being used as a DLL?

2

Hey, thanks for reporting this. This looks like an unintended side effect of adopting the D3D12 Agility SDK. We will look at fixing this. I filled a bug report here: Unity Issue Tracker - Windows player with a custom .exe file crashes in FixupD3D12SDKPath

3

Hey is there any chance you could try using non-development build? This flaw seems to only be present in development builds.

4

Sorry, my license is now expired so no further development or testing is possible. This specific bug was the reason that I did not renew the license.