init_unreal.py is not automatically running

Development Pipeline & Plugins
, ,
1

I’m having trouble getting a Python plugin to load so I can call custom modules within the editor. It appears Unreal Engine isn’t running my `init_unreal.py` file. I can confirm that when running it via Python remote execution, the `init_unreal` code correctly adds the path to `sys.path`, allowing module imports. Additionally, editing `init_unreal.py` to point to the plugin directory and moving it to the `[Project]/Content/Python/` folder also enables automatic execution and module imports.

I would prefer to have Unreal automatically run the init_unreal.py inside the `[Plug-in]/Content/Python/` folder for cleanliness. Any suggestions on what I might be doing wrong?

2

Steps to Reproduce
Windows

  1. Make a plugin.
  2. Add init_unreal.py to [Plug-in]/Content/Python/
  3. Edit init_unreal.py to append its directory to sys.path
  4. Put your Custom Module into [Plug-in]/Content/Python/
  5. Launch Editor
  6. Try to import your custom module.
  7. Get error saying could not find module.
3

Is your plugin marked as containing content? Only plugins with content have mount roots that we can run Python files from:

“CanContainContent”: true,

4

Yes, it is set to contain content.

[Image Removed]

5

I haven’t been able to reproduce this with the given steps, though I’m not sure what you’re doing with sys.path in step 3. Any Content/Python folders are automatically added to sys.path, so you shouldn’t need to do anything there to be able to import a module from the Content/Python folder of a plugin.

My test layout looks like this:

  • [Plug-in]/Content/Python/init_unreal.py
  • [Plug-in]/Content/Python/my_module/__init__.py

I’m able to run “import my_module” from either init_unreal.py or via the output log without any errors.

6

hmm, that is how I am structuring my plugin as well.

[Plug-in]/Content/Python/:[Image Removed]This is my .uplugin file, do you see any issues in here:

{
	"FileVersion": 3,
	"Version": 1,
	"VersionName": "0.1",
	"FriendlyName": "Cyclops UE",
	"Description": "Cyclops Render Plugin",
	"Category": "tool",
	"CreatedBy": "Tcool",
	"CreatedByURL": "",
	"DocsURL": "",
	"MarketplaceURL": "",
	"SupportURL": "",
	"CanContainContent": true,
	"IsBetaVersion": true,
	"IsExperimentalVersion": true,
	"Installed": false,
	"Plugins": [
		{
			"Name": "PythonScriptPlugin",
			"Enabled": true
		}
	]
}
7

That seems correct. The plugin itself is enabled for the project? (I assume it must be, otherwise it wouldn’t work at all).

If you’re able to reproduce this in a clean project, then can you please provide that so I can investigate further?

8

Hey Jamie,

Sorry for the delayed reply, here is the project with the plugin in it.

  1. open project
  2. open output log
  3. send this python command: `import cyclops`
  4. Error will occur.

The expected outcome is:

  1. open project
  2. open output log
  3. send this python command: `from cyclops.hello_world_tool import hello
  4. “Hello, Unreal Engine!” will be printed into the log.

Let me know if you have any questions.

Tucker

9

In the given zip, CyclopsUE.uplugin is in FWProduction/Plugins/CyclopsUE/Content. CyclopsUE.uplugin needs to be at FWProduction/Plugins/CyclopsUE for UE to recognize that as a plugin.

With that fixed, ‘import cyclops’ works fine. ‘from cyclops.hello_world_tool import hello’ still doesn’t, as it needs to be ‘from cyclops.tools.hello_world_tool import hello’ to match the folder layout.

10

Ah perfect, I thought I had the structure correct. Thank you!

oh yea that was a typo omitting the tools. Good catch!