Ppsspp: Monster Hunter 3rd Portable HD Graphics Glitches like geometrical probelm

[Gamemulatorer]

What happens?

There are graphical glitch in ppsspp v1.7.1-204 gitbuild

Screenshot

What should happen?

Seems ok in ppsspp v1.7.1-195 beta gitbuild

Screenshot

What hardware, operating system, and PPSSPP version? On desktop, GPU matters for graphical issues.

Mali-450 MP4
Android 5.1
2GB RAM

[Abbanon]

Myself as well as other users are experiencing identical results on the Windows Git build 204-gd08a2eed6
This is when the new culling change was implemented that fixed #11593 and #11591
Before the culling change there is no issue.

GE dump:
https://cdn.discordapp.com/attachments/480103153803460614/516643877642567681/NPJB40001_0001.ppdmp

Screenshot for reference:

[hrydgard]

Thanks for reporting. Should probably have reviewed that change more...

[unknownbrackets]

At this point, I guess it means there's a case #11172 doesn't catch? #11594 just made it flush in the right place.

Maybe it means there's an issue with the cull reversing for non-triangle strips?

https://github.com/hrydgard/ppsspp/pull/11172/files#diff-aadfcd071e41f07936f2d354f1ee44faL1585

@weihuoya what do you think? You can open the ppdmp files as if they were games, and it will render the scene with basically the same draw commands the game used.

-[Unknown]

[unknownbrackets]

I'm actually not able to reproduce this issue with that dump.

Just to lay out a timeline, because I want to make sure there has been no confusion:

• v1.6.3-497-gead4946fd: "range culling" is implemented which fixes graphical glitches in several games.
• v1.7.1-188-g4942c52f7: "cull mode flipping" optimization expanded to cover more games.
• v1.7.1-204-gd08a2eed6: "cull mode flipping" optimization is fixed to flush correctly.
• v1.7.1-213-g93bb96dbd: [Unknown] cannot reproduce the issue with the GE dump.

If you're able to reproduce this, even when loading the GE dump above as a game, it may mean this issue is GPU driver specific.

That seems a bit odd since the "cull mode flipping" optimization doesn't seem likely to behave differently on different GPU drivers (unlike the "range culling" feature, which is a bit more dangerous as far as GPU drivers go.) However, this was reported to happen only starting with v1.7.1-204-gd08a2eed6 which means it's related to "cull mode flipping" - right?

I tried reproducing both on an NVIDIA and Adreno device.

-[Unknown]

[Peduls]

Just tested on v1.7.1-213-g93bb96dbd and the issue is present for me. I have an NVIDIA GeForce GTX 1070 with the latest drivers.

[leopard20]

@unknownbrackets I'm not able to reproduce this with that dump either (neither on Vulkan nor OGL). But it does happen:

Try this dump instead:
NPJB40001_0005.ppdmp.zip

[unknownbrackets]

Strange, doesn't happen for me with that one either. I tried all the backends and with vertex cache on and software skinning off, in case they were related.

-[Unknown]

[leopard20]

@unknownbrackets Weird. I tried my own dump just now, but I don't see it either! It turns out that the dump doesn't show the issue. Maybe it's the drivers being stupid again?!

[unknownbrackets]

It seems like it doesn't happen with dumps (except for Peduls?), which is very weird. However, I have found a way to reproduce the issue.

So far it appears to happen when newPrim != prim. Using this on the prim fixes it:

            if (newPrim != prim)
                goto bail;

It might be an acceptable workaround if the games that benefit from this optimization most don't use different prim types? I'm guessing something goes wrong with the triangle combining when the prim type switches?

-[Unknown]

[leopard20]

I think Peduls is using his own game, not the dump! (look at the names in the screenshots again)

So far it appears to happen when newPrim != prim. Using this on the prim fixes it:

          if (newPrim != prim)
              goto bail;

It might be an acceptable workaround if the games that benefit from this optimization most don't use different prim types? I'm guessing something goes wrong with the triangle combining when the prim type switches?

-[Unknown]

If this part was for me, then unfortunately I can't be of any help 'cuz I don't understand computer graphics! :(

[Peduls]

Right, I was just booting the game like normal.

[Gamemulatorer]

Issue still appear :(

Screenshot

PPSSPP DUMP

MH3PHD.ppdmp.zip

[leopard20]

Strange. It's been fixed for me:

Does it happen in that mission only?

[Gamemulatorer]

Fixes in some map/area but only happen in that particular mission weird :v

Screenshot

[Gamemulatorer]

@leopard20 can you try that mission? (Location Tundra)

[unknownbrackets]

Does the tundra area have issues even with older builds? Maybe it's a separate issue.

It might help to try to create a GE dump of that area, although this issue didn't reproduce super well in dumps...

-[Unknown]

[leopard20]

@Emulatorer Sorry I accidentally formatted my phone recently and I've lost all my saved data. I'm playing all games from the beginning. :(
Can you upload your save data for me to test?

@unknownbrackets I think the dump he uploaded a few comments above is the Tundra map.

[leopard20]

@unknownbrackets Yep. I can definitely reproduce with the dump:
https://github.com/hrydgard/ppsspp/files/2633052/MH3PHD.ppdmp.zip

@Emulatorer No need for the save data anymore! :)

[Gamemulatorer]

@leopard20 thanks 👍

@unknownbrackets didn't have that issue in the previous build/version of ppsspp except gitbuild v1.7.1-204