How to use FCoreDelegates::OnMountPak.Execute

Development Programming & Scripting
1

Hi

I have been working on mounting pak files at runtime and recently read here that FCoreDelegates::OnMountPak.Execute could simplify a lot my code and solve one of my problems.
Except that I didn’t find any documentation on this function. And my code doesn’t work :

if (FCoreDelegates::OnMountPak.IsBound()) // returns true
 {
		const FString PakFilPath = GetFileLocalPakPath();

		FCoreDelegates::OnMountPak.Execute(PakFilPath, 0); // returns true

		LoadedMesh = Cast<UStaticMesh>(StaticLoadObject(UStaticMesh::StaticClass(), NULL,TEXT(" /Game/BigRoom/placard_cuisine_7/placard_cuisine_7.placard_cuisine_7" )));

		if (LoadedMesh)
		{
			this->SetStaticMesh(LoadedMesh);
		}
	}

It just returns the following errors, just like if nothing had been mounted at all :

[2015.12.10-11.12.48:546][  7]LogLinker:Warning: Can't find file '/Game/BigRoom/placard_cuisine_7/placard_cuisine_7'
[2015.12.10-11.12.48:547][  7]LogUObjectGlobals:Warning: Failed to load '/Game/BigRoom/placard_cuisine_7/placard_cuisine_7': Can't find file '/Game/BigRoom/placard_cuisine_7/placard_cuisine_7'
[2015.12.10-11.12.48:547][  7]LogLinker:Warning: Can't find file '/Game/BigRoom/placard_cuisine_7/placard_cuisine_7'
[2015.12.10-11.12.48:548][  7]LogUObjectGlobals:Warning: Failed to load '/Game/BigRoom/placard_cuisine_7/placard_cuisine_7': Can't find file '/Game/BigRoom/placard_cuisine_7/placard_cuisine_7'
[2015.12.10-11.12.48:548][  7]LogUObjectGlobals:Warning: Failed to find object 'StaticMesh /Game/BigRoom/placard_cuisine_7/placard_cuisine_7.placard_cuisine_7'

Does anyone have an idea ?
Is there a way to list all the currently mounted assets ?

2

In 4.11 there’s a new module called HotfixManager which can download PAK files used to patch your game at runtime (not exe, just BPs, content, etc.) Here’s the code I wrote to mount PAK files:

if (!FCoreDelegates::OnMountPak.IsBound())
{
	UE_LOG(LogHotfixManager, Error, TEXT("PAK file (%s) could not be mounted because OnMountPak is not bound"), *FileHeader.FileName);
	return false;
}
FString PakLocation = FString::Printf(TEXT("%s/%s"), *GetCachedDirectory(), *FileHeader.DLName);
if (FCoreDelegates::OnMountPak.Execute(PakLocation, 0))
{
	MountedPakFiles.Add(FileHeader.DLName);
	UE_LOG(LogHotfixManager, Log, TEXT("Hotfix mounted PAK file (%s)"), *FileHeader.FileName);
3

Thank you for your answer, but it looks like your code is very similar to mine :

  • You are using a FileHeader (what class is this?) but I don’t see how it can affect the mounting
  • “MountedPakFiles.Add(FileHeader.DLName);” is only here to remember which pak file has been mounted, right ? Or some other use ?
  • I am using the 4.10 so maybe I am missing something here but I don’t see what. Are you using the HotfixManager from 4.11 that you are talking about in this code ?

Could my error simply be here:

LoadedMesh = Cast<UStaticMesh>(StaticLoadObject(UStaticMesh::StaticClass(), NULL, TEXT("Game/BigRoom/placard_cuisine_7/placard_cuisine_7.placard_cuisine_7" )));

Maybe the reference path is updated during mounting with a “Engine/” or something ? Here I assume that the reference is exactly how it was in the original unreal project used to create the pak file.

4

Note I said 4.11 so I you’ll need that first. It’s in Engine/Runtime/Online/Hotfix

My guess is your path does not match what is in the PAK file. Use UnrealPAK to dump it back out and see if that’s the problem

5

No that is not the problem either.
I am going to wait for the 4.11 to try the HotfixManager. For now my workaround will do the trick.

Thank you

6

Hi, I am having the same problem. Have you figured it out? I generated PAK files manually with UnrealPak.exe but then I have no idea where in my packaged game directories should I put these PAKs, and I don’t know how to implement GetFileLocalPakPath() in your code snippet.

7

After the PAK files are loaded, how to get the uasset files out from its inside?

8

How should I specify the path to StaticLoadObject, which in your case is " /Game/BigRoom/placard_cuisine_7/placard_cuisine_7.placard_cuisine_7"

9

I loaded map from pak file, it can be loaded into the map, but the map of uasset gone, how to load the map with uasset? Thanks. （现在加载出的关卡没有uasset，（没有索引关系），关卡的索引关系在哪儿存放呢？怎么加载可以加载出索引）

10

Where the heck is this path “Engine/Runtime/Online/Hotfix”?
I can’t find this path in the API documentation. I can’t find it in any engine source on GitHub. If this is online documentation please provide direct links and not a file path description.

11

Sorry Engine/Source/Runtime/Online/Hotfix. FiF would have found it too. In later releases it was moved to a plugin along with the other online*, so Engine/Plugins/Online/OnlineFramework/Source/Hotfix

12

Thanks for the quick response. I have a connected question to this one. Should I just open up a another topic or append it here? It relates to mounting PAK files as well but it involves an unusual use case. FWIW, it’s been suggested I identify as being from Missing Worlds Media, Inc. due to our contract with Epic games.

13

You should ask on UDN then.

14

Guys please help me!

15