ROM Hack [MH4U/MHX] ROM Hacking Guide

[dasding]

I don't know how to PM anyone. But aside from that, can we get the fixed DD mca converter link?

Quoting @Benuno here (from the SoJ thread):
@mister_gamer about the .mca problem: @dasding was so nice to adjust his .mca converter for dual destinies. Maybe it also works for you with Spirits of Justice and fixes the problem . Please PM me for the link ( I'm a bit busy atm).

Sure: Download

The adjustments i made are for DD only, i didn't test it with MH or any other game. Could work or even improve the results. (Could be i made a off by one error in the MH version, didn't had the time to properly test)

 

[bomigoton]

Sure: Download

The adjustments i made are for DD only, i didn't test it with MH or any other game. Could work or even improve the results. (Could be i made a off by one error in the MH version, didn't had the time to properly test)

Hello Ding,
I know we have MH4U as western release, but I also got MH4 for my 3ds for series completenes. Do you know if there was ever a english ui patch or anything for MH4? Just curious, will get along with japanese too.

 

[dasding]

Hello Ding,
I know we have MH4U as western release, but I also got MH4 for my 3ds for series completenes. Do you know if there was ever a english ui patch or anything for MH4? Just curious, will get along with japanese too.

i don't know of any

 

[23edsa]

@dasding, Hello, Im looking for weapon models either from 4u or Gen, I remember seeing them somewhere, for example kiranico uses them. Is there an easy way to get them, like may be a downloadable pack?

 

[Deleted User]

@dasding, Hello, Im looking for weapon models either from 4u or Gen, I remember seeing them somewhere, for example kiranico uses them. Is there an easy way to get them, like may be a downloadable pack?

I believe you either have to dump them yourself, or get someone who dumped the game to send you the files

 

[trainboy2019]

I've been using these tools to extract models and textures from Ace Attorney SoJ, but some of the textures are giving me this error.
"Error Unsupported Version: 16550"
Here is one of those files. What should I do to extract it?

 

[Kyrio]

I've been using these tools to extract models and textures from Ace Attorney SoJ, but some of the textures are giving me this error.
"Error Unsupported Version: 16550"
Here is one of those files. What should I do to extract it?

Couldn't help trying by myself after I told you about Scarlet on the SoJ thread. And it works miracles

 

[trainboy2019]

Couldn't help trying by myself after I told you about Scarlet on the SoJ thread. And it works miracles

Thank you so much!

 

[lys1030]

Deviants of Astalos from MHXX

 

[Zeff-555]

@dasding How do I edit the gmd files?

I want to make a Spanish translation of MHXX

 

[Kibido]

Is it possible to literally remove some textures in the game? Like the puff of dirt that comes off your feet while you run. Figured I'd ask before going through the hassle.

 

[dasding]

Is it possible to literally remove some textures in the game? Like the puff of dirt that comes off your feet while you run. Figured I'd ask before going through the hassle.

you could make the whole texture transparent effectively making it invisible, if you just delete the file the game will crash.

 

[Kibido]

you could make the whole texture transparent effectively making it invisible, if you just delete the file the game will crash.

Great, thanks for the heads up.

 

[Kibido]

Hmm, I can't get your tool to extract the arcfs. romfs extracts perfectly but arcfs just opens and closes immediately without extracting anything. Any idea of what it could be?

EDIT: My bad, I overlooked that Python must be in C:\Python27

 

[Kibido]

Is there a way of converting multiple .tex files into .png all at once? Having to drag and drop one at a time when there are so many is a bit of a chore.

 

[DarkSynopsis]

Is there a way of converting multiple .tex files into .png all at once? Having to drag and drop one at a time when there are so many is a bit of a chore.

Can create a .bat file to do the trick.

Something like

for %%f in (*.tex) do c:\python27\python.exe tools/textool.py -x -v -ra %%f

Should convert any .tex file found in the folder when you run it, no drag/drop, can't recall why I've got "-x -v -ra" when the default in png2tex is "-c -v"

 

[Drai196]

Is it possible to had weapon and armor to the romfs?
I have my mh3u textures replacement ready(ex:Lambent on narga X fit perfectly ;P) and a bunch of custom relic but, I don't want to replace the existing one. I made my research in the arcfs and I know there's an arcindex(I searched into the files with hexedit) but, I'm kind of lost now do I simply have to modify it or there's more to do?

 

[dasding]

Is it possible to had weapon and armor to the romfs?
I have my mh3u textures replacement ready(ex:Lambent on narga X fit perfectly ;P) and a bunch of custom relic but, I don't want to replace the existing one. I made my research in the arcfs and I know there's an arcindex(I searched into the files with hexedit) but, I'm kind of lost now do I simply have to modify it or there's more to do?

just adding files won't add them to the game, you would have to make code.bin changes

 

[1NSaNe]

Welcome Hunters,

this is my guide to modding Monster Hunter 4 and X to your desire. I will provide tools especially for textures, sfx/music and extracting/repacking arc files. The tools work with MHX and MH4U. But at some steps you will have to choose the correct script for the respective game.
So let's get started.

Video showing steps 3-5:

Spoiler

You will need:

• Python 2.7.11 (Don't worry, no heavy console-fu needed, at least for the HANS method)
• Pillow (Used for Texture Stuff)
• Harddrive with at least ~10GB free disk space.
• A 3DS with either CFW OR Homebrew (for MH4U)
  
• A 3DS with CFW (for MHX)

1. Prerequisites
Download and install Python, Pillow and MH Mod Tools from the following links.
Install Python to the default location C:\Python27!

Downloads:
Download MH Mod Tools (rev05)

64 Bit
Download Python 2.7.11 (64 Bit)
Download Pillow (64 Bit)

32 Bit
Download Python 2.7.11 (32 Bit)
Download Pillow (32 Bit)

2. Acquire your romfs.bin
There are two ways to get your romfs.bin.
a) extract it from an decrypted cia of your game.
b) dump it from your cartridge with braindump.

3. Extract romfs.bin and arc files
All you need to do for this step is place your romfs.bin (it has to be named like this) in the MH Mod Tools folder next to the .bat files (You should make sure that there is no space in the path to your modfolder).
Then double click 1_extract_romfs.bat.
Wait for it to finish.
Then double click on 2_extract_arcfs.bat.
This step will take some time. arcfs consists of ~100.000 files.

4. Modifying Files
After Step 3 you will end up with 2 folders: romfs and arcfs. Basically romfs contains all uncompressed files of the game and arcfs are all the compressed files (which are nearly all) extracted. e.g. you will find battle BGM in romfs, but SFX in arcfs.

4.1 Modifying Sound Files
Sound files have the filesuffix .mca .

4.1.1 Convert .mca to .wav
Find an .mca file in romfs or arcfs and copy it to the main folder (next to the .bat files). Then drag & drop it onto 3_mca2wav.bat. After the black window closes you will end up with a wav file which you can play back in any common media player.

4.1.2 Convert .wav to .mca
To inject your own music into the game you have to convert it to a .mca file. If you have your music not in .wav format use something like audacity to convert it to .wav first. Then copy your .wav file in the main folder (next to the .bat files) and drag & drop it onto either 3_wav2mca_mh4.bat or 3_wav2mca_mhx.bat, depending on which game you're currently modifying. After the black window closes you will end up with your .mca file which you can then use to replace any .mca in romfs or arcfs.

4.2 Modifying Textures
Texture files have the filesuffix .tex .

4.2.1 Convert .tex to .png
Find an .tex file in arcfs and copy it to the main folder (next to the .bat files). Then drag & drop it onto 3_tex2png.bat. After the black window closes you will end up with a single .png and a .meta file depending on the texture there could also be a second png file with the alpha/reflection channel. Don't mess with the .meta file you will need it to convert the png back to .tex. Now you can edit your .png in your favorite image editor.

4.2.2 Convert .png to .tex

To convert the modified .png back to a .tex drag & drop it onto 3_tex2png.bat. After the black window closes you will end up with your modified .tex which you can then use to replace the original one.
Attention:
Due to preserving the best quality the encoding will autmatically be uncompressed, so the modified file will be multiple times bigger than the original. If you want to control the compression you will have to learn console-fu and have look at the .bat and tools/textool.py.

4.3 Modifying any File
Just open files of interest to you in your favorite hex editor and start hacking

5. Repack Everything
After you did all your modifications and replaced the original files in arcfs and romfs it's time to repackage everything.
For this just double click on 4_repack_arcfs_mh4.bat or 4_repack_arcfs_mhx.bat, depending on the game your modifying. This Step will take a lot of time due to all files being recompressed and packaged.
After the black window closes double click on 5_repack_romfs.bat and you will end up with a new romfs file called modded_romfs.bin.

6. Getting your mod on your 3ds
6.1 HANS (only MH4U)
Copy your modded_romfs.bin onto your SD card under:
/HANS/00126100.bin for EU copy
/HANS/00126300.bin for US copy
/HANS/0011D700.bin for MH4G copy
Then start your game with HANS and your modded romfs enabled.

6.2 CIA repack (MH4U and MHX)
6.2.1 Vanilla CIA
Use your modded_romfs.bin to repackage the vanilla .cia of your game.

6.2.2 Update CIA [Advanced Users]
Before extracting the arcfs and modifying the files you'll want to remove all files you don't plan to modify from the romfs folder. Next you also have to extract the romfs of the update CIA you plan to repack and merge it with the romfs folder (overwrite already existing files). Now you can continue with extracting the arcfs, modifying files, and repackaging the arc files. Then rebuild the romfs folder into a romfs.bin and repackage it into your update cia.

6.3 LayeredFS (MH4U and MHX v1.00) [Advanced Users]
You actually don't need the modded_romfs.bin, you just need to copy the modified files from romfs onto your SD card with the configured path of the layeredfs plugin. Files you modified in the arcfs folder got repacked into .arc files. You have to figure out which one under romfs/arc/ contains your modified file and you only need to copy that one or just copy it all.

7. Done, enjoy your mod!
I hope my tutorial was understandable and of help to you. If you managed to put a cool mod together don't hesitate to reply here, pm me or tweet me screenshots of your work. I would appreciate that a lot!

Also tell me if you have suggestions on improving this guide or the tools.

8. Bonus
I ripped the Attack on Titan Deviljho Texture from the MHXR Smartphone game for you.
Try to mod it into your game

Textures
Result Screenshots

Changelog
rev05
* fixed an issue with mca2wav
* updated wav2dsp

Credits
@Asia81 for his guide on CIA repackaging
@dnasdw for 3dstool
@moghedien for etc1 decoding
@Gericom for etc1 encoding
@jackoalan for dsp encoding
Anon1 and Anon2 you're the best

Hey, first of all, thanks for your work.
Second, im trying to inject the Spanish text files into ur patch, but following this tutorial results into Music/GFX edit. There is no support about texts. I googled and found ArcTool with MH4 support, but doesnt give more info about usage, so i still lost. There is a way to extract the text file and edit via notepad and not Hex edit? thanks a lot

 

[Kibido]

Where do I find the textures for the graphical effects, like the dirt coming off of the ground when you slam a weapon or that white effect when you swing your GS?