uAsset and Uexp : How do read pointers on uasset files ?

Extraction and unpacking of game archives and compression, encryption, obfuscation, decoding of unknown files
Tgames
Posts: 81
Joined: Mon Apr 01, 2019 10:49 am

uAsset and Uexp : How do read pointers on uasset files ?

Post by Tgames »

Hi all :)

I want to read pointers in a uasset files to modifying values on his associated uexp file.

For example :
Uasset File:
Image

UExp File :
Image

Files here :
uassetUexp.zip


I would like a explanation do read pointers in uasset files and found the value on the uexp.
OR a script to list all data and the offset in the other file.

Thanks a lot !
Best Regards !
Tgames
Posts: 81
Joined: Mon Apr 01, 2019 10:49 am

Re: uAsset and Uexp : How do read pointers on uasset files ?

Post by Tgames »

Anyone know how to understand the pointers in uasset files ? To Read the corresponding value on the uexp
not ihaku
Posts: 3
Joined: Sat Aug 17, 2019 10:13 am

Re: uAsset and Uexp : How do read pointers on uasset files ?

Post by not ihaku »

im looking for the same thing, staring at some files aswell for another game.
Tgames
Posts: 81
Joined: Mon Apr 01, 2019 10:49 am

Re: uAsset and Uexp : How do read pointers on uasset files ?

Post by Tgames »

Anyone can help us ? lol :mrgreen:
Tgames
Posts: 81
Joined: Mon Apr 01, 2019 10:49 am

Re: uAsset and Uexp : How do read pointers on uasset files ?

Post by Tgames »

Can someone you look into it ?
atom0s
Posts: 250
Joined: Sat Dec 27, 2014 8:49 pm

Re: uAsset and Uexp : How do read pointers on uasset files ?

Post by atom0s »

There's a tool for doing this on Fortnites assets which should give you a general idea on how it works. Source code of that can be found here:
https://github.com/SirWaddles/JohnWickParse/

You can also signup to gain access to Unreals source code which will give you full access to how the files are generated.
not ihaku
Posts: 3
Joined: Sat Aug 17, 2019 10:13 am

Re: uAsset and Uexp : How do read pointers on uasset files ?

Post by not ihaku »

so i figured out how to do this.
you can use the parser linked above to check if your edits are right.

values in hex are stored as little endian float, use this website to convert https://gregstoll.com/~gregstoll/floattohex/ (make sure to check swap endianness since big endian is default!)

now you can kinda go by trial and error with the help of the merged json file. simply look at the json, pick the number you're looking for (movespeed for example) convert it with the website and then do a search in hex for it. then just change it to whatever you want. values that can only have whole numbers are just stored as a normal hex value.

in the game im making a mod for, the default offset between values seems to be 0x1D but that could be entirely different for you.
masagrator
Posts: 82
Joined: Sat Dec 22, 2018 10:03 am

Re: uAsset and Uexp : How do read pointers on uasset files ?

Post by masagrator »

Author of JohnWickParse is working on import function.
Tool is good for params, but not for blueprints, so it's not perfect.
4epuxa
Posts: 5
Joined: Thu Jul 02, 2020 8:50 am

Re: uAsset and Uexp : How do read pointers on uasset files ?

Post by 4epuxa »

This program has errors. Somebody can help me editing without that program?
stocolov
Posts: 1
Joined: Wed Sep 02, 2020 5:44 pm

Re: uAsset and Uexp : How do read pointers on uasset files ?

Post by stocolov »

Friends has a tutorial on how to use the JohnWickParse tool. I just want to edit values ​​like in this example, I don't need to extract anything from the assets. This part of using the hexdecimal editor I already have a notion. One more question where is this folder marked in red on the image that I don't find inside the project? Thanks in advance...

Image
Shokoniraya
Posts: 416
Joined: Sat Sep 15, 2018 5:22 am

Re: uAsset and Uexp : How do read pointers on uasset files ?

Post by Shokoniraya »

stocolov wrote:Friends has a tutorial on how to use the JohnWickParse tool. I just want to edit values ​​like in this example, I don't need to extract anything from the assets. This part of using the hexdecimal editor I already have a notion. One more question where is this folder marked in red on the image that I don't find inside the project? Thanks in advance...

Image


if you want to change values in unreal engine, you have to decompile scripts to find right value or do research on file format
and about marked folder: some strings generated by engine in name table and those names belogs to game project data (uncooked game), that means if you can't find it in game files, then you have to debug the game (hard way) or by decompiling scripts to find it out