[Mod] Gran Turismo plus (bug fixes and restored content) - alpha 1 released

[pez2k]

Hello, I would like to ask these questions:
1. Is the mod made to advance the knowledge of GT1's code, allowing more to make mods of it?
2. Will there be new content added?
3. How big can the mod get before it breaks the game?

I'm not quite sure what the first question means, but all of the tools that I wrote are open-source, and I'll release the source files for the mod at some point like I did with GT2+.

New content is addressed in the FAQ in the first post - not possible right now, so adding 1 car breaks the game.

 

[Memesbro]

I'm not quite sure what the first question means, but all of the tools that I wrote are open-source, and I'll release the source files for the mod at some point like I did with GT2+.

What I mean is that since the knowledge with GT1 modding is very minimal, is the purpose of this mod to expand the knowledge of GT1 modding

 

[pez2k]

What I mean is that since the knowledge with GT1 modding is very minimal, is the purpose of this mod to expand the knowledge of GT1 modding

The purpose of the mod is to fix bugs and allow the missing cars to be used in GT mode. I did of course have to figure out a lot of file formats in order to do so, but that's to be expected with modding a game that hasn't really been modified in any depth before.

 

[trar]

This looks very good, hoping a release for the USA version is coming soon.

 

[pez2k]

This looks very good, hoping a release for the USA version is coming soon.

Coming, yes, eventually. Soon, probably not I'm afraid. There are a decent few technical hurdles to cross first, and I've got plenty of work still to put into GT2+ too. Hopefully with enough research GT1 will end up like GT2 where the same content will mostly work in all three regions, but if not then I'd need to more or less develop a second fork of the mod based on the US version, and a third for the Japanese equivalent. Some stuff will have to be done separately per version as some of the file formats differ, but the mod definitely isn't done until all three regions are supported, so they will happen.

 

[pez2k]

Well, one technical hurdle has been crossed - I've figured out how to start making code edits. This basically involved deciphering what Polyphony's loader program did on startup to decompress and boot the game's executable, reproducing that in tool code, then getting the game to boot from a later stage of the process instead, with the desired edits applied.

One thing I'd had in mind but couldn't implement properly without permanent code changes was revising how the Dodge Copperhead is handled in terms of buying and selling it, to solve some problems with the original implementation.

In short, the Copperhead has a price of 0, and there's a check on the buy car screen to grey out the buy button if the car's price is 0. This prevents players from buying the license prize Copperhead, but means that the car can't be sold. It also means that the car costs nothing to trade from another memory card, so it's possible for players to be tempted to buy as many as they can, which then effectively bricks their save because their garage is full of unsellable cars.

The way that I've reworked it is to change which field in the car data that the code checks. One field seems to be totally unused, so moving the check to that field instead of the price lets the buyability be controlled separately to the price. After that, it was simply a case of setting that field to a specific value for the Copperhead to make it unbuyable, and giving it a price.

It now costs money to trade:

And can be sold for a small amount of credits:

Don't take this as a sign that alpha 2 is coming any time soon, but at the very least it's one major step towards making it possible.

 

[Indigo Mizumi]

That's interesting. Does this mean the purchase/sell value of other prizes can be tweaked? Cause a lot of the high level race car prizes are worth hilariously little.

 

[pez2k]

That's interesting. Does this mean the purchase/sell value of other prizes can be tweaked? Cause a lot of the high level race car prizes are worth hilariously little.

Purchase prices are simple to change yeah, and the sale price is just 50% of it with a 10% bonus for the matching manufacturer. Prize car values are intentionally all set to 20,000Cr in GT1, presumably because selling them was not intended to be a way of making money.

 

[karelpipa]

That's interesting. Does this mean the purchase/sell value of other prizes can be tweaked? Cause a lot of the high level race car prizes are worth hilariously little.

Its for the better. Gt2 is kinda broken with its resell calue of prize cars

 

[KasumiR]

Its for the better. Gt2 is kinda broken with its resell calue of prize cars

There's really no need to make people grind in a 25 year old game though... Especially when each mod update needs a new save. I remember one of modders locked all races behind IA license, saying it's "hardcore", but it didn't make the game harder, it ruined the pacing and made it more tedious and boring having to go through tons of obligatory tests we already did over and over, with loading times and all.

Same with car sales: there's no way anybody is expecting us to grind for prize money in PS1 era Gran Turismos now, hell, if you see at Final Fantasy re-releases, they have X3 speed and cheats for outright winning everything and skipping encounters built-in because they value people's time instead of trying to make an old game many already completed before feel like a chore... there's always challenges if you WANT though.

 

[pez2k]

Just to be totally clear, I have no intention of changing the game difficulty or balancing in any way. This mod is about bug fixes and cut content, not about redesigning the game or trying to make some sort of modern re-release. Gran Turismo is Gran Turismo, for better and for worse.

 

[mistamontiel]

Gameshark my good man

 

[submaniac93]

GT1 needs no grinding anyways. You can complete the entire game with just 2 cars you can buy in the used dealerships lol

 

[Memesbro]

Well, one technical hurdle has been crossed - I've figured out how to start making code edits. This basically involved deciphering what Polyphony's loader program did on startup to decompress and boot the game's executable, reproducing that in tool code, then getting the game to boot from a later stage of the process instead, with the desired edits applied.

One thing I'd had in mind but couldn't implement properly without permanent code changes was revising how the Dodge Copperhead is handled in terms of buying and selling it, to solve some problems with the original implementation.

In short, the Copperhead has a price of 0, and there's a check on the buy car screen to grey out the buy button if the car's price is 0. This prevents players from buying the license prize Copperhead, but means that the car can't be sold. It also means that the car costs nothing to trade from another memory card, so it's possible for players to be tempted to buy as many as they can, which then effectively bricks their save because their garage is full of unsellable cars.

The way that I've reworked it is to change which field in the car data that the code checks. One field seems to be totally unused, so moving the check to that field instead of the price lets the buyability be controlled separately to the price. After that, it was simply a case of setting that field to a specific value for the Copperhead to make it unbuyable, and giving it a price.

It now costs money to trade:

And can be sold for a small amount of credits:

Don't take this as a sign that alpha 2 is coming any time soon, but at the very least it's one major step towards making it possible.

Wait, so could this be the key to eventually adding new events and cars?

 

[pez2k]

Wait, so could this be the key to eventually adding new events and cars?

It's at least a step towards figuring out if that will ever be possible.

 

[Memesbro]

It's at least a step towards figuring out if that will ever be possible.

This is really exciting!

 

[karelpipa]

GT1 needs no grinding anyways. You can complete the entire game with just 2 cars you can buy in the used dealerships lol

what about the powertrain and national championships?

 

[Memesbro]

what about the powertrain and national championships?

They aren't crucial to the game's progression, they are there in case you want to do something that isn't in the GT League

 

[submaniac93]

what about the powertrain and national championships?

The 2 cars you need are:

• A cheap used Skyline R32 GTR. That can carry you throughout the entire game starting with the Normal Cup (don't forget that the Tuned Car Cup and SSR-11 II Endurance don't allow RMs!) minus the UK vs US championship, and the FF and Lightweight Cups. Win any of the non-japanese LM Editions from the US vs JP or UK vs JP championships with it to beat the UK vs US championship and the FR Cup.
• a used FTO GPX '94 to beat the FF and Lightwieght Cups.

Technically 3 cars, but only 2 you need to buy, and one trip through the Normal Cup with hopefully a few quali times will grant you enough money to max out the R32 (without the RM!) to beat 90% of the game lol

And yes, i ignored the very start indeed.
You can get any starter car to beat the Sunday Cup until you get enough money to buy an R32, twice should suffice considering the cheapest R32 '89 is like barely 20k. Selling that starter and the Demio Aspec twice will award you way more than enough heh
And if you're good enough to get golds, this can all be made much more straightforward if you can get any of the prize cars, but specifically the 400R, as it's a Skyline, and therefore does all the of what the R32 does, but better as stock. And the Concept Car/ TRD3000GT can be your starter car otherwise heh

 

[karelpipa]

I see it now. GT1 is a very short game afterall

 

[Indigo Mizumi]

The real challenge is to beat the game without buying a car. I've done it before.

 

[madtownjmac01]

The real challenge is to beat the game without buying a car. I've done it before.

I just started attempting this. Using that Demio A-Spec for the FF & Lightweight Championships about did me in...

 

[m2595]

It's a small thing, I agree, but all of the NSXes in the game, even the 1990 version, have HID headlamps. I don't remember the older ones having that option IRL (i think it became available in 1997, but I might be mistaken). Could that be a thing that would go in the to-do-list for future releases?

 

[pez2k]

It's a small thing, I agree, but all of the NSXes in the game, even the 1990 version, have HID headlamps. I don't remember the older ones having that option IRL (i think it became available in 1997, but I might be mistaken). Could that be a thing that would go in the to-do-list for future releases?

Do you have any examples of the difference between the two types?

 

[m2595]

It's basically the color of the light beam that's different - older model years should have both low beam and high beam with the yellowish glow that the halogen lamps are known for and the 97s should have the low beams glowing blueish, HID-like, like they already do in the game.
Here's how an NSX with halogen headlights looks like, that's perhaps the best photo I could find:

 

[submaniac93]

TIL and it makes sense

 

[pez2k]

It's basically the color of the light beam that's different - older model years should have both low beam and high beam with the yellowish glow that the halogen lamps are known for and the 97s should have the low beams glowing blueish, HID-like, like they already do in the game.

Ah, thanks, should just be a bit of a recolour then. I'll add it to the to-do list.

 

[m2595]

Ah, thanks, should just be a bit of a recolour then. I'll add it to the to-do list.

Yep. I even made a quick before - and - after snaps to show what I meant. The picture on the left is the vanilla arrangement, the pic on the right is what the headlights should look like. The car I used is the '90, the same applies for the '92 Type R - the '97, Type S and Type S Zero (I think) were available with HID either as an option or as standard IRL. Thanks in advance, BTW!

 

[matherto]

Is there a chance of changing the opponent pools?

EDIT - apologies, should've read the FAQ.

 

[pez2k]

Is there a chance of changing the opponent pools?

EDIT - apologies, should've read the FAQ.

They're hardcoded (unlike GT2 where the event data is just in one of the data files) and most of the entry lists are shared between multiple events. It's potentially possible to do now, but would involve some reverse-engineering work and I don't currently know of any bugs that would need them to be changed.