All Unreal Engine Model Swaps End up Crashing or Getting T-Posed (Solved)

[Raccooncity1998]

I started learning Unreal Engine just to do a very simple character swap and I've been watching over 30 videos on YouTube but unfortunately I could barely find any tutorials for model swaps. most of them are all about materials and textures. the one and only video that explained everything from start to finish was this one:

  Reveal hidden contents

 

(however this video has a major issue as well. nothing was mentioned about the model used for swapping the PhysicsAsset and Skeleton and it took me a very long time to figure out)

==================================================
The Overall Procedure to Mod an Unreal Engine Game
==================================================
Let's say I want to swap the exact same model without even making any changes (just to see if it works):

1. Convert the model to .psk using either Fmodel or Umodel
2. Open the file in blender and export it to .fbx (you'd also need to check and uncheck some options for an error-free export)
3. Open the correct unreal engine version for the game you'd wish to mod
4. Create a project (excluding the Shared Content)
5. Create the same folder hierarchies in Unreal Engine
6. Drag and drop the .fbx file into the folder to import the Skeletal Mesh (PhysicsAsset and Skeleton will be generated by UE)
7. Name all three assets correctly
8. Allocate a Chunk ID only to the Skeletal Mesh (because the mesh must use the original PhysicsAsset and Skeleton from the game not the ones generated by UE).
9. Export it
10. Add _P at the end of the mod name so that it can override the original file

11. put the mod in the Paks folder

 

==================================================
How I Managed to Fix the T-Pose Issue for One Game
==================================================
I've tested 3 game so far. in Echo (2017) the model is always in T-pose, in Alone in the Dark (2024) the game crashes (I noticed one of the reasons that a game may end up crashing is the model being way too big when you export it to .fbx and you can simply scale it down to 0.01 to fix the issue. but it wasn't the case for this one) and in AEW Fight Forever (2023) the same T-pose issue as Echo (2017)'s. 

I managed to fix the issue for AEW Fight Forever (2023). I noticed that when I export the .psk format using Umodel, a text file is generated where you can find the exact location for PhysicsAsset and Skeleton and AEW used a dummy for all of them which was in a different folder. I imported the dummy in UE and then linked the PhysicsAsset and Skeleton to dummy's and then it worked perfectly.

But unfortunately for the other two games, the PhysicsAssets and Skeletons are in the same folder and when I import the .fbx file they are already generated and linked automatically by UE (next to Skeletal Mesh) and it's not like you can link them to any other models or something and when I assign the Chunk ID to the Skeletal Mesh I expect it to work but it doesn't. it either crashes or gets t-posed. am I doing something wrong? should I assign PhysicsAsset and Skeleton manually somehow someway?

==================================================
The Solutions that I Tried to Fix the T-Pose Issue
==================================================
I also tried to Chunk ID the generated PhysicsAsset and Skeleton files as well just to see what happens with them included in the mod and to my surprise the animations worked but the mesh, on the other hand, was totally messed up (Alone in the Dark, on the other hand, wouldn't crash anymore with Physics and Skeleton included but the mesh had the exact same issue).

 

I needed to know which one of the two assets was needed for the animations and it was none other than the Skeleton. meaning that the Skeletal Mesh cannot find the Skeleton but why? isn't the Skeletal Mesh already linked to PhysicsAsset and Skeleton once you import the .fbx file? 

What exactly am I missing here ? I've been working on this for over two weeks and tried many many trial and errors but I kept failing. any help would be greatly appreciated. 

Edited March 3 by Raccooncity1998
solved the problem

[Raccooncity1998]

For those of you that might run into this issue. IT'S THE ARMATURE. can't believe it took me a couple of weeks!!!

It looks like the correct naming for the armature in blender is important and it should be named "Armature". I never would have thought that imported models with .psk/.psa addons would have any issues. there are a couple of .psk addons out there from different developers and it seems like there's a customized version that's made for UE4 modding and it automatically fixes everything:

https://github.com/matyalatte/blender3d_import_psk_psa

 

If you need to use the latest versions from other developers just keep in mind that the correct naming for the armature and also the model size are important. sometimes imported models are way too big. to fix them just scale them down to 0.01 (when you're about to export them to .fbx) and you'll be fine.

 

If you just started learning unreal engine mods, this video can also help you but swapping models in blender, that you see in this video, is NOT the way it's done. you should NEVER adjust a mesh with no armature like that. you need to rigify your model temporarily with a basic human armature first and then do the adjustments accordingly otherwise you'll end up deforming your model. for model swapping use the first video):

 

Edited March 3 by Raccooncity1998
grammar

[Lillavatti]

im having this issue trying to mod Life is Strange Remastered. Im following this guide and am at the last part UE_Modding/IntermediateModding/ChangingSK.md at main · Dmgvol/UE_Modding · GitHub The crash happens after i put the renamed skeleton in Packages/UniqueSkeletons/Characters (Thats where the og skeleton is) the game will crash and say Fatal Error! I downloaded blender 3.1.2 and followed the tutorial in this thread and got the old psk addon but its still crashing