Hacking help extracting models from .PAC

[startropicz]

i'm digging into the files i've extracted from the saiki k 3DS game (Saiki Kusuo no Psi Nan: Shijō Psi Dai no Psi Nan!?) and i've hit a wall. the extracted romfs data is all stored in PAC files... looking into them via HxD shows these house multiple files, including the model files i'm trying so very desperately to get my grubby little hands on. however, i have no idea how to extract them. i can't code, i don't know how to run things from the cmd line ffs. trying to make a quickbms script has been hell, i have no idea what i'm doing. i've extracted things from Persona Q and it went just fine, i extracted things from Persona Q2 and hit a brick wall in a different way, but the files from Saiki K are completely different. no organization, just... PAC files full of everything. Persona Q and Q2 had everything sorted out in folders and it made sense, this is hell. i have no idea what i'm doing. i just wanna make the models usable in mmd... please help me i'm hopelessly lost TT

Post automatically merged: Dec 11, 2024

adding context and such to this

the content in the extractedromfs folder looks like this

the stream folder contains a bunch of music tracks which aren't that hard to convert into something i can actually play (wav, ogg, etc) which is not what i'm interested in

snd_boot.bcsar is also just audio i think

sroll.pac is the staff credits sequence
the esp_ files are for a minigame that uses flat png images
i'm assuming the quests aren't anything tangible
i'm assuming the maps are, well, maps
i need none of these things

the boot.pac and boot_cia.pac hold data that points in the right direction i think. they call on the various ch##.pac files, which hold models i'm pretty sure. models and textures, maybe animations?
here's what it shows in HxD that makes me assume such:

looking into the game_ files, i see something very very useful in the game_chr.pac hex

oooh boy is that models is that a model ooooh golly oh gee whiz i think that's kokomi teruhashi's model it's calling on ooooh man oh geez !!!

inside the very excitable ch files...

oooh boy oh geez that's the it that's my boy there he is it's saiki it's kusuo freaking saiki and EVEN kusuke freaking saiki wowie wowzers

and ch01a.pac is even more directly close to the saiki kusuo model ooooh man oh geez!!!

i have no idea how to extract them or snip them out, though

3DSExplorer can tell me the magic headers of the folder partitions they're in, i also have .bin files of the decrypted things as well as the extracted headers and whatnot

i just don't know where else to go from here. ahahaha...

 

[Erizur]

If you're interested. QuickBMS has a script for add header PAC files. (https://aluigi.altervista.org/bms/add_pac.bms)

This extracts all the contents of the PAC, which outputs known 3DS 3D formats (.ctex, cmdl), but they will be compressed. The header for each file starts with LZS. Luckily, QuickBMS has also a script for this header, on the official website. (https://aluigi.altervista.org/bms/lzs.bms)

After decompression, you can view the models using Ohana3DS: https://gbatemp.net/threads/wip-ohana3ds-tool.392576/

I have tried this before as I wanted to make an English translation for the game, unfortunately the files that contain the game text seem to be compressed in a .ftx file (which is just LZS compressed, that extracts an .ftxt file) that has a FTXT header that I do not know the format for. QuickBMS has scripts for .ftx files, but they're from Amiga-era formats and they do not match with the header information, but from what I know, seems like it's just a compression format that outputs a normal .txt file.