Gran Turismo 3: A-spec - License test B-4 demo fails

[ICantSeeIt]

PCSX2 version: v1.5.0-dev-2286-g41c49faa8

PCSX2 options: Defaults, no settings changes made a difference. Tried presets 1 and 2 (Safest and Safe) in Emulation settings, also tried disabling speedhacks.

Plugins used: Tested with various GSdx varieties:

• GSdx 20180213122600 (MSVC 19.00 SSE4.1/AVX) 1.1.0 [GSdx32-SSE4]
• GSdx 0 (MSVC 18.00, SSE41) 0.1.16 [gsdx32-sse4-r5875]
• GSdx 20180213122600 (MSVC 19.00 SSE2/AVX) 1.1.0 [GSdx32-SSE2]
• GSdx 20180213122600 (MSVC 19.00 AVX2/AVX2) 1.1.0 [GSdx32-AVX2]

PAD: LilyPad (20180213122600) 0.12.1 [LilyPad] SPU2: SPU2-X 20180213122600 2.0.0 [Spu2-X] CDVD: cdvdGigaherz 20180213122600 0.11.0 [cdvdGigaherz] USB: USBnull FW: FWnull DEV9: DEV9null

Default settings

Description of the issue: During license test B-4, when running the demo, the car deviates from the line and goes off the track during the turn. This causes the game to enter the license test fail-state and the car stops. Also tested on actual hardware to confirm that it works fine on there.

How to reproduce the issue: Run the demo for license test B-4 (no save needed).

Last known version to work: None that I know of, but never tested this before.

PC specifications: CPU: Intel i7 5820k @stock GPU: AMD Radeon HD 5770 1GB RAM: 16GB DDR4 OS: Windows 10 64-bit

[FlatOutPS2]

Go to Config > Emulation Settings > EE/IOP, and set Round Mode to "Nearest" and Clamping Mode to "Normal". If it doesn't work set Round Mode to "Chop/Zero" and Clamping Mode to "Full".

[ghost]

It's a complicated situation, the game need the EE clamp mode to full to solve the car behavior. But this fix cause a emulator crash when you load a level or a demo sequence (TLB misses). This is related to these issues: https://github.com/PCSX2/pcsx2/issues/2240 https://github.com/PCSX2/pcsx2/issues/2245

[refractionpcsx2]

It's a bit of a rock and a hard place this one. You need clamping to fix the graphics, but you need to lower it to fix the license tests. The way we have it now seemed like the best option as you will see the graphics all the time, but you will probably only do the license tests once, so we generally tell people to turn off the automatic game fixes just while they do the licenses then turn them back on for the rest of the game.

[ICantSeeIt]

I'm not sure I understand fully. Is there something different that the game is doing in the license tests that it doesn't do during other races? Assuming the demo is just recorded input being fed in (pretty sure about this), then this different physics behavior would be present everywhere else in the game, right? From what I can tell, this issue causes cars to skid much more easily.

So the current workaround is to use the settings that give accurate physics in the license tests (just the demos for the license tests? Or while driving the actual test itself as well?) then use the settings that give accurate graphics during the rest of the game? Can you reiterate which of those settings are which again, please? This behavior isn't noted in the wiki, so I (or somebody else, doesn't matter) could add it there.

This reminds me of the process Dolphin devs used to fix their own rounding behavior: they were comparing replays in Mario Kart Wii between emulator and console. I imagine having replays would be helpful for debugging, since you can save a replay from any race in GT3 and play it back from the main menu replay theater.

[lightningterror]

If it's related to #2240 then the two issues can be merged together to avoid duplicates.

[Helium-4]

Pretty much every single license demo in every instance of Gran Turismo has desync, none of the times match the results from a PS2 (granted times might even be different between various PS2 models). You can affect the result to a degree by changing EE clamping and rounding, FPU negative div hack can also affect demo playback.

EDIT:By affecting playback I do not mean fixing it, no matter the settings it will desync.

[ghost]

I sugest trying full EE clamping. Maybe GT3 doesn't have the rounding issues of it's successor.

[kamfretoz]

Still an issue as of Nightly v1.7.5335

https://github.com/PCSX2/pcsx2/assets/14798312/60373e62-016d-47f7-b2d1-6c72bc9596fe

[Mrlinkwii]

ok this is odd as of v1.7.5357 , the PAL version works the NTSC-U/NTSC-J dont and has the issue

[gtgamer468]

I did further testing in the latest master (1.7.5370) with all four GTC titles (Concepts, so 2001 Tokyo, 2002 Tokyo-Seoul, 2002 Tokyo-Geneva PAL, and 2002 Tokyo-Geneva NTSC), and also GT4P (Prologue). All of these games failed with the license demonstrations even with Interpreter EE mode. GT4 and TT does not load at all with any of them as it returns to the previous menu. Everything else were in default settings with only EE being used in Interpreter mode with all of these tests.

[Somberyu]

I'm having a similar issue with license tests B-7 and B-8 on a PAL version. In B-7, the car fails similarly to this report, while on B-8 it crashes into a wall on the last corner. I've tried various emulation settings, but they seem to mess up the simulations even more. The most successful settings are default aside from EE clamping mode set to Full and VU0 and VU1 clamping modes set to Extra + Preserve sign on PCSX2 v1.7.5968 For the record, B-4 demo works flawlessly. Extra note: I tried on my PS2, and in the B-8 test demo the car avoids the wall very narrowly, and in B-7 the car is further left when it arrives to the penultimate corner, due to which the steering input keeps it on the track. It seems like the cars are more oversteer/slide prone on the emulator. Further addition: It seems that setting division rounding mode to Chop/Zero may be a little bit more accurate. B-7 test demo completes successfully with it, but others still have issues. That could just be coincidental, of course