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Sonic Adventure 1+2 Custom DLC?

Posted: Mon Mar 04, 2019 2:55 pm
by Blayer98
I was just wondering, is it possible to make custom DLC for these games? I’d love to make my own, and I understand that the already existing DLC was decrypted, but that’s all I’ve heard.

Re: Sonic Adventure 1+2 Custom DLC?

Posted: Mon Mar 04, 2019 4:00 pm
by Xiden
Custom Contests are about the only thing we can do with SA1. I know its possible to make custom chao colors for SA2 by editing vmu hex files. (Not sure how this is done). Thats about as close to DLC as we could probably make.

Re: Sonic Adventure 1+2 Custom DLC?

Posted: Mon Mar 04, 2019 4:39 pm
by Blayer98
Oh, I assume the formats haven’t been fully figured out to make fully custom DLC then...? not even a model swap would work? (If anyone’s attempted to make a encryptor program)

Re: Sonic Adventure 1+2 Custom DLC?

Posted: Mon Mar 04, 2019 8:04 pm
by Xiden
Blayer98 wrote:Oh, I assume the formats haven’t been fully figured out to make fully custom DLC then...? not even a model swap would work? (If anyone’s attempted to make a encryptor program)


Depends also if the dlc was already on the game itself or not too (not sure in the case of SA1). Model swap may work if the model code was actually on the vmu

Re: Sonic Adventure 1+2 Custom DLC?

Posted: Tue Mar 05, 2019 12:35 am
by DR TEAMCAST
i'd certainly be more interested in finding out how they added the AT&T worldnet banners and halloween\christmas decorations for levels. even if the textures we're on disc, there's no reason a new sonic1 disc can't be created with more textures

problem is time it takes to actually figure that out, then create new content once we do. new DLC with the network functions working again it would really add a lot of depth to the game

edit: there's also people porting the levels from sonic heroes into sa1, i might actually take a serious look at that because the model\level\texture\etc formats are not too different from dc version to steam version of sa1, so there's that too

Re: Sonic Adventure 1+2 Custom DLC?

Posted: Tue Mar 05, 2019 5:09 am
by Blayer98
Xiden wrote:
Blayer98 wrote:Oh, I assume the formats haven’t been fully figured out to make fully custom DLC then...? not even a model swap would work? (If anyone’s attempted to make a encryptor program)


Depends also if the dlc was already on the game itself or not too (not sure in the case of SA1). Model swap may work if the model code was actually on the vmu


DLC was given out in VMS files for SA1 and SA2. AFAIK, with SA2, apparently the PRS file isn’t compressed.

Yeah, I’ve read a SA1/DX hacking thread on another site and sonicblur’s tool (which can be downloaded from there) can decrypt VMS content and you can see all the files in all your saves afaik. It’s also possible to extract the model data by hex editor.

http://forums.sonicretro.org/index.php? ... 91&st=2600

Here’s that thread that I read up on. Page 131.

By model swap, I thought that the model was in it’s own file, not within one PRS file.

I was later thinking of swaps like sounds, text, textures, etc., and then encrypting the VMS file again.

“The decrypted VMS file is pretty straightforward. It contains the name of the DLC, the icon, DLC event-related text strings, textures (PVM), sometimes music/sound data (MLT archives), and at the very bottom there's a PRS-compressed binary file with model data, probably code too.”

Re: Sonic Adventure 1+2 Custom DLC?

Posted: Wed Mar 06, 2019 2:16 am
by DR TEAMCAST
Blayer98 wrote:
Xiden wrote:
Blayer98 wrote:Oh, I assume the formats haven’t been fully figured out to make fully custom DLC then...? not even a model swap would work? (If anyone’s attempted to make a encryptor program)


Depends also if the dlc was already on the game itself or not too (not sure in the case of SA1). Model swap may work if the model code was actually on the vmu


DLC was given out in VMS files for SA1 and SA2. AFAIK, with SA2, apparently the PRS file isn’t compressed.

Yeah, I’ve read a SA1/DX hacking thread on another site and sonicblur’s tool (which can be downloaded from there) can decrypt VMS content and you can see all the files in all your saves afaik. It’s also possible to extract the model data by hex editor.

http://forums.sonicretro.org/index.php? ... 91&st=2600

Here’s that thread that I read up on.

By model swap, I thought that the model was in it’s own file, not within one PRS file.

I was later thinking of swaps like sounds, text, textures, etc., and then encrypting the VMS file again.

“The decrypted VMS file is pretty straightforward. It contains the name of the DLC, the icon, DLC event-related text strings, textures (PVM), sometimes music/sound data (MLT archives), and at the very bottom there's a PRS-compressed binary file with model data, probably code too.”

holy crap man this is really useful lol

Re: Sonic Adventure 1+2 Custom DLC?

Posted: Wed Mar 06, 2019 1:37 pm
by Blayer98
Yeah, I’m going to have a more in-depth look tomorrow and see if I can potentially get this working :) I’d probably need to see if I can re-encrypt the VMS file though

Re: Sonic Adventure 1+2 Custom DLC?

Posted: Wed Mar 06, 2019 5:24 pm
by Blayer98
So I found this thread as well, and needless to say, I am not familiar with Perl code nor would I be able to encrypt data into base64... This will definitely take me ages to figure out @_@ But I guess I might as well try lol

https://assemblergames.com/threads/deco ... ata.60036/

Re: Sonic Adventure 1+2 Custom DLC?

Posted: Thu Mar 07, 2019 8:40 am
by Blayer98
I’ve had a look at the outfit DLC in SA2 and since they’re only 2 blocks, the outfit DLC is probably on the disc...