[Mod] Gran Turismo 2 plus (bug fixes, restored content and new content) - beta 7 released

  • Thread starter pez2k
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Hello!
Are these elements fixable/changeable?
  • Floating trees in Pikes Peak.
  • Tyre textures sticking through the rear (JGTC NSX's, Unisia Skyline, haven't found more yet.)
  • Oddly placed concrete-esque building seen on the right side on the final straight in the first licence tests (The long right-handers).
  • I found the Unisia Skyline to sort-of panic when taking off from the start line. In second gear the car starts to lose 80% of power, revs jump oddly, kinda gets back into shape when I let off the throttle for a sec or when a gear change occurs. I'm not 100% sure if this is intended to be an interpretation of a slipping clutch or something or it's an actual glitch in the system. I did make some changes in the car's settings but nothing of the sort that changes the way the car performs engine-wise.
 
Tracks aren't yet editable, so it's a no for two of those. Tyres sticking through the bodywork is sometimes just the suspension setup combined with too low a ride height, and sometimes issues with the draw order of faces in the car model (i.e. what the game considers to block the view of other parts) where the wheels are drawn above certain bodywork elements. This is in theory fixable, but is either an accepted side effect of the car setup from PD, or extremely time-consuming to fix when it's a model issue. Maybe if the model format is understood better in future it'll be more feasible.

I'll have a look at the Unisia GT-R - does it do it with the default setup, and do the other JGTC GT-Rs do it too?
 
I'm getting an error when i try to patch it in.

upload_2019-12-29_11-27-49.png


What am I doing wrong?
 
Your disc image is incorrect, either a bad rip, the wrong disc, or the wrong region. Redump.org lists the correct checksum for a good rip that you can check yours against.
 
pez2k
Tracks aren't yet editable, so it's a no for two of those. Tyres sticking through the bodywork is sometimes just the suspension setup combined with too low a ride height, and sometimes issues with the draw order of faces in the car model (i.e. what the game considers to block the view of other parts) where the wheels are drawn above certain bodywork elements. This is in theory fixable, but is either an accepted side effect of the car setup from PD, or extremely time-consuming to fix when it's a model issue. Maybe if the model format is understood better in future it'll be more feasible.

I'll have a look at the Unisia GT-R - does it do it with the default setup, and do the other JGTC GT-Rs do it too?
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Thanks for the swift answer.
I'm currently re-progressing through the game, so a lack of good info on my part at the moment, apologies.

Another thought that popped up - In the patch notes I noticed car model changes (exhaust placements, liveries etc.). Is it possible to further alter a car's model? One thing that kiiiiinda bothers me is the modeling of the rear diffuser on the Daishin (and Xanavi) Silvia - or rather lack of it. 3D-fying it would make it a bit more pleasing to the eye, kinda like the 3D diffusers on, for example, the Pennzoil Skyline. Or does it need some sort of reference to make it a better model?

Quick edit: How far do you intend to push with the "New content" idea for the game?
 
Car model edits are possible, they're just a whole ton of work to do as it's all hex editing by hand. Adding new faces is again possible, but giving them reflections is not. Once someone cracks how the reflections work then model editing will be a ton easier, but for now it's prohibitively time-consuming for anything other than essential fixes.

GT2+ itself isn't going to have a lot of entirely new content, as there's a limit on the number of car models that the game can support, so the focus is on restoring stuff that PD planned or started. I have made a few new cars on the side though such as the Alfa 155 Q4, which may end up in their own mod at some point.
 
I'm guessing "Insider information" on the how's and why's of the game's mechanics isn't very plentiful yet, considering the sub-20 years since release...
 
Masgel
I'm guessing "Insider information" on the how's and why's of the game's mechanics isn't very plentiful yet, considering the sub-20 years since release...
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That and everyone who worked on the game was Japanese, so even if any of them had written anything about the formats I wouldn't know as I don't speak their language.

GTvsForza
I highly doubt that Drag Mode is one of them...
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There's virtually nothing left of drag mode, I'm not even sure it was ever really started. The only thing even close to a drag track is the 0-400m Machine Test on the Test Course, and as for drag cars the 180SX is complete, the GT-R is broken, and the Celica is completely absent. There are no events, there's not even any data about the event type. Pretty much the only hard evidence in the files that it was ever planned is an unused menu button on the Arcade disc.
 
Any chance of getting the Esprit GT1 added to GT All-Stars? Or how about the HKS Drag R33 GTR added to the Tuned Turbo No.1 Cup race at Test Course?
Another neat idea I had was making the final MR challenge race even harder, by adding the Tommy Kaira ZZII, Elise GT1, and GT-One Road Car to the AI pool. :sly:👍
 
CVPI93
Any chance of getting the Esprit GT1 added to GT All-Stars? Or how about the HKS Drag R33 GTR added to the Tuned Turbo No.1 Cup race at Test Course?
Another neat idea I had was making the final MR challenge race even harder, by adding the Tommy Kaira ZZII, Elise GT1, and GT-One Road Car to the AI pool. :sly:👍
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I'm probably not going to do anything that affects the difficulty significantly, and starting to make design changes is a slippery slope. The Esprit GT1 only seems to have been an opponent for an event that was cut, but not for All-Stars (which is very close to the maximum number of potential opponents as it is). The drag GT-R isn't used as an opponent anywhere, and it'd reduce the chance of getting a lineup without a drag car.
 
Yeah, the front tyres just spin all of the power away in the first few gears so it's nowhere near as fast off the line as it should be. Widening the fronts and narrowing the rears back to equal width as on the real car makes it a lot quicker.
 
submaniac93
However that's my end goal for my mod hat has no ETA lol
The game has a massive amount of unused/duplicated opponent entries that i'll use to create new ones for cars that should have been used as AIs 👍
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i'm so excited for your mod, cant wait for release ever, even if it takes 20+ years xD

EDIT: i guess, this will be my last message for this year, so everyone Happy New Year!
 
It's been a while, so here's two teasers in one screenshot:

familia-arc.png


I think all of the behind-the-scenes work to support multiple regions is now mostly done, I just need to do JP and US versions of the various menu edits (having both Opel and Vauxhall in North City, having a Mercedes Special dealer, etc.), and figure out how I'm going to get the full Honda dealer working in the US version.

The plan for the next version is also to include most or all of the special Rally Car models from the Arcade disc. These are generally the normal cars with a special name, minor engine upgrades, dirt tyres, stage 2 weight reduction and a racing modification. I'll be giving them the same upgrade options as the normal cars, including stage 3 weight reduction, so that the normal and Rally versions are completely equivalent when fully modified. The Rally version however will come with all of the tyres for free, as it's technically a race car.

I don't have a timescale for all of this being done yet, but I wanted to show that there is progress going on with the mod.
 
Masgel
How much can be changed/corrected in the menus, in terms of colours, text and just plain errors?
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Nothing easily - the menus are made up of dozens / hundreds of tiny tiles, each of which have their own palettes. The file format is more or less known, there's just no reasonable way to turn them into something that can be edited without going insane. It's possible to hex edit menus, but just adding Vauxhall to the Opel version of North City took me a whole week of work so I'm not eager to do any more that way.

The visuals of the menu and the invisible buttons that the cursor snaps to are also two different file formats. The format for the menu buttons data is only roughly known, enough to tweak what buttons do but not enough to be sure of how it works completely.

lightbox87
I'm aware that this mod works fine in PCSX-Reloaded on Retroarch, but... the issue is with both BizHawk (version 2.3.2) and Mednafen (version 1.23.0). When I try to get to the Used Cars selection to get a car in order to start my career, the game crashes and it stops completely
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Just to bring this point back up again as there's some good news - I've tried out the mod in BizHawk, and a tooling fix I made back in June sorted out this issue. The next release therefore won't crash in that way, and I'll give it a good run through on BizHawk to see if there are any other issues.
 
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pez2k
Nothing easily - the menus are made up of dozens / hundreds of tiny tiles, each of which have their own palettes. The file format is more or less known, there's just no reasonable way to turn them into something that can be edited without going insane. It's possible to hex edit menus, but just adding Vauxhall to the Opel version of North City took me a whole week of work so I'm not eager to do any more that way.

The visuals of the menu and the invisible buttons that the cursor snaps to are also two different file formats. The format for the menu buttons data is only roughly known, enough to tweak what buttons do but not enough to be sure of how it works completely.
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So overall, it's more worth it to work on functions, rather than form/aesthetics, right?
 
Masgel
So overall, it's more worth it to work on functions, rather than form/aesthetics, right?
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I'm not aware of any bugs with the menu functionality in the final release for each region, only graphical problems like missing icons. That's largely why I've not gotten around to looking into the button data any more than I have.
 
pez2k
I'm not aware of any bugs with the menu functionality in the final release for each region, only graphical problems like missing icons. That's largely why I've not gotten around to looking into the button data any more than I have.
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I ain't aware of any menu function bugs yet, was mostly referring to missing capitalizations, odd, discoloured boxes and the like. If it's a bother for you (or anyone else doing mods like you) to work on just for visual pleasantry then I probably shouldn't look into them too much.

Just trying to find a general idea of what can be worked on with the game, what you and other modders can do and what is possible in the current framework.
 
CaravanSS76
Will you fix the BMW wheel shop bug?
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It's not a bug, it's an intentional licensing restriction. I'm not aware of any way to bypass it yet.

Masgel
I ain't aware of any menu function bugs yet, was mostly referring to missing capitalizations, odd, discoloured boxes and the like. If it's a bother for you (or anyone else doing mods like you) to work on just for visual pleasantry then I probably shouldn't look into them too much.
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Yeah, I'm happy to take suggestions on things that may need to be fixed, but there's not much point in mentioning menu visuals currently as the tooling doesn't exist to fix them (and most have been mentioned already to be honest).
 
Hey, I really like what you've added but it only works on less accurate emulators.
The game will freeze on a real PS1 or Mednafen if you try to access any of the new cars etc. Is there something I can do to fix that?
CRC number of my patched disc image matches up with yours.
 
Oligopolist
Hey, I really like what you've added but it only works on less accurate emulators.
The game will freeze on a real PS1 or Mednafen if you try to access any of the new cars etc.
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I've already fixed this, and the next version won't have the same issue.

One of the file formats I wasn't quite rebuilding correctly, but I spotted and fixed the inconsistency in my tools back in June. After investigating earlier today, it turns out that that was the only thing that had been causing crashes (in Mednafen at least).
 
First of all, kudos to you, @pez2k, for fixing and enhancing this great game.

[EDIT] Just saw the answer to the post above: probably next version will work on PSPs as well by the looks of it. I'll try it out as soon as it's available and post my results here.

I just wanted to point out that I've not been able to make the mod work with the PSX2PSP tool (which creates PSP-compatible PBPs to play any PSX game on the platform): as soon as you try to enter a modified dealership, the system freezes and requires an hard reset. That's probably the same issue that causes the emulators to have a slight "delay" when entering the Special section on modified dealerships, but I'm not sure.

My two cents:
I've not delved deep into how PBPs execute PS1 code but, by the looks of it, it might be a misaligned access which causes the CPU to pick up code from a data segment and crash. Since the PSP OS appearently has no memory management (or perhaps it's just disabled while running PBPs), the whole system crashes with an unrecoverable error (meaning PBPs do not have interpreters or dynarecs but execute plain PSX MIPS object code in compatibility mode, perhaps using a supervisor to map PSX BIOS syscalls to PSP OS ones).

Nevertheless, keep up the good work!
 
pez2k
I'm impressed - the cause was actually some misaligned data in a file - the car names specifically.
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I'm flattered.

Turns out I'm quite fond of the MIPS architecture from an university course, even if not the specific flavour used in the PlayStation (and definitely a computer architecture junkie).

Feel free to ask, I'd be glad to be of any help with this project of yours.
 

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