Pursuit Force graphic issues

[weihuoya]

What happens?

car run under road in some place, test on android, PC seem doesn't has this issues.

another issue, graphic glitches vulkan backend only. opengl and direct3d work ok.

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

PPSSPP version:
ppsspp-v1.6.3-248-g098a7ffea-windows-amd64.7z
ppsspp-v1.6.3-248-g098a7ffea-android.apk

this game use hundreds of bezier lines. like Acid 2 use hundreds of splines.

[unknownbrackets]

So there are two separate issues here - do they both happen only on Vulkan? Or does the mobile issue happen on OpenGL and Vulkan both, and the other issue happen only on Vulkan?

-[Unknown]

[weihuoya]

graphic glitches happen only on vulkan(PC and mobile).

car run under road test on mobile opengl backend, vulkan backend is not playable for graphic glitches.

[xebra]

We can avoid this bug(maybe second issue only) using the following fix.

StateMappingVulkan.cpp

key.depthClampEnable = gstate.isClippingEnabled() && gstate_c.Supports(GPU_SUPPORTS_DEPTH_CLAMP);

to

key.depthClampEnable = false;

Probably, the same issue as D3D11.
D3D11: Specify DepthClipEnable = TRUE when creating rasterizer states… 480a05d

[unknownbrackets]

Hmm, but if the game specified that flag, it indicates to clamp depth to the [0, 65535] range. Maybe the flag is ignored when drawing beziers or something?

-[Unknown]

[Leopard20]

Weird. I don't have this problem on my phone using Vulkan. Instead I get a weird "mirroring" effect when I enable "Hardware Tessellation". The game is not playable on Vulkan without this option. The opposite is true with OpenGL. If I enable this option the game becomes super slow!

[unknownbrackets]

@Leopard20 check the features tab in system information - your device may not even support depth clamping.

-[Unknown]

[Leopard20]

Right. It doesn't!

[weihuoya]

unchecked simulate block transfer, the game is running smoother.

when use low spline/bezier curves quality, car run under road in some place. medium and high work fine.

[xebra]

Ah, low quality is not spline/bezier. It's just drawing control mesh(no curve tessellation/evaluation). So it's just specification(not bug). However I fixed it and I will commit later.

@unknownbrackets Vulkan depth clamp issue is related to Vulkan driver bug or unsupported feature maybe.

[Anuskuss]

I have experienced the same graphical issues on my machine on Vulkan. First on Linux (hinted in #10477) and now on Windows too.

Vulkan:

OpenGL:

As of 1.6.3-323 I can't start any game with Vulkan at all. My computer becomes unresponsive and after a few seconds I get:

Lost the Vulkan device!
Try to continue?

ppsspplog.txt

[unknownbrackets]

Is v1.6.3-323-g945eab6fe the first build that stopped working? What's the last build that works?

Also - which positioning of the yellow is "correct"?

Can you try that same exact scene in the software renderer? It might be that we need to clamp depth at the fragment level to be correct (which is unfortunate.) It will help to know if the software renderer has the same glitch.

-[Unknown]

[Anuskuss]

Last good: v1.6.3-220-g309036069
First bad: v1.6.3-221-g06340bfa9

The front part of the car is missing, maybe that's easier to find?

[Anuskuss]

Before yellow roadblock (depth map)

OpenGL

Vulkan

After

OpenGL

Vulkan

[unknownbrackets]

I wonder if that error is caused by KhronosGroup/glslang#1418, if it's happening on PC.

What does depth look like using the software renderer? In theory, that's the correct depth.

-[Unknown]

[Anuskuss]

Before

After

[unknownbrackets]

Okay, then probably OpenGL is correct. Since it seems like it renders mostly right in the software renderer, can you try making a GE debugger dump?

To do this, open the game and select Debug -> GE debugger..., then when it's displaying the scene, press Record in the top right. After a second or so, it'll finish and save a trace of the drawing activity.

After that, check the memstick/PSP/SYSTEM/DUMP folder and it'll have created a file named something like "ULES12345_0000.ppdmp". You can zip that and then drag and drop it into a reply here.

I can even try running this on a real PSP to compare (that's still experimental, though.) Then I could see what depth /should/ be for sure.

-[Unknown]

[Anuskuss]

So I have to switch to Software Renderer, click Step Tex in the GE Debugger until the texture appears in the preview window, then Record and then Resume?
UCES00019_0001.zip

[unknownbrackets]

Ah - unfortunately, that didn't capture anything.

It's probably fine to make the GE debugger dump using any backend. But something failed if it creates a 2KB file - this is the second time I've seen that now, there must be a bug causing it. But if you click do Record/Resume again, it should work after a couple tries at worst.

-[Unknown]

[Anuskuss]

Backend: Vulkan
Software Renderer: off

Again, I waited for the yellow roadblock to appear in the texture preview, Record -> Resume. This time theres actually stuff in the file.

UCES00019_0001.zip

[unknownbrackets]

Hmm, it seems to heavily use minz/maxz and viewport z params. Maybe something isn't dirtying properly, or else there's somewhere we're handling these depth params wrong.

Most of the drawing is done with the viewport centered on the first 50% of depth (0 - 16383), and with a maxz of 16383.

-[Unknown]

[Anuskuss]

Do note that this is working fine with earlier builds.
Last good: v1.5.4-189-gc1a23658d
First bad: v1.5.4-197-gea50561c8

[unknownbrackets]

Right, so that points to depth clamping - #10454. But the question is, why. The PSP definitely clamps depth, but maybe we need to do it in the fragment shader for it to be accurate.

I think right now, we're deforming polygons when it clamps, perhaps, which is only okay in flat or mostly-flat cases.

-[Unknown]

[unknownbrackets]

How does this look with recent changes now?

-[Unknown]

[weihuoya]

test latest dev build, vulkan still have graphic issues.

use low spline/bezier curves quality, car run under road in some place, but not worse than before.

[Anuskuss]

Everything is fine for me again. I couldn't test it since the Lost the Vulkan device! error but as of v1.6.3-482-g025e478d2 (last bad: v1.6.3-479-g637a17a66) it's all working again and the graphics are correct.

[hrydgard]

I believe this is fixed, closing. Please reopen if not.

[hrydgard]

Apparently not, reopening.

[ghost]

Yeah this is still a thing even on the current git versions and the latest stable version.
Tried out Pursuit Force Extreme Justice and the graphics are messed up all over the place.
Playing with DX9 will make the game super slow for some reason (its because its falling back to software renderer).

[unknownbrackets]

A GE frame dump of an issue currently happening would be helpful. The previous frame dump still seems to work fine.

-[Unknown]

[ghost]

Vertex cache + HW Tessellation make this game faster on my phone R9 Mali-G52 GPU

Vertex cache and HW Tessellation is off

I also notice some rendering issue the road sometimes is flickering?
Pursuit Force.ppdmp.zip

[ghost]

Can no longer reproduce my issue as I mentioned above maybe because of 16bf519?

[Anuskuss]

There are multiple issues in this thread:

1. Pursuit Force graphic issues #11216 (comment) (top): Spline/bezier curve quality set to Low / not a bug
2. Pursuit Force graphic issues #11216 (comment) (bottom): Probably related to D3D11 and Vulkan depth clamp incorrectly without clip distance or geometry shading support #11399 / fixed by Handle guardband clip/cull better for hardware backends #14833
3. Pursuit Force graphic issues #11216 (comment): Missing hardware feature / not a bug
4. Pursuit Force graphic issues #11216 (comment) (top): Fixed as of v1.6.3-482-g025e478d2
5. Pursuit Force graphic issues #11216 (comment) (bottom): Fixed as of v1.6.3-482-g025e478d2
6. D3D11 and Vulkan depth clamp incorrectly without clip distance or geometry shading support #11399 (comment): Fixed by Handle guardband clip/cull better for hardware backends #14833
7. Pursuit Force graphic issues #11216 (comment): Probably missing hardware feature / not a bug
8. Pursuit Force graphic issues #11216 (comment): Related to D3D11 and Vulkan depth clamp incorrectly without clip distance or geometry shading support #11399 / fixed by Handle guardband clip/cull better for hardware backends #14833

[unknownbrackets]

https://cdn.discordapp.com/attachments/480103153803460614/551370781482024961/unknown.png seems like it was probably also the guardband issue.

But please note that the guardband fixes are NOT currently implemented for:

• Some macOS / iOS devices
• Phones with Mali GPUs (not an insignificant number of devices)
• Probably Raspberry Pis, but not verified

I think it's a bit early to fly the flag of victory.

-[Unknown]

[Saramagrean]

v1.12.3-232-gb6e7fe1aa still happen (All backends).

GE Dump.
DUMP.zip

[unknownbrackets]

Right, that's #11399. As noted there, clamping against the wrong boundary is still not worked around.

-[Unknown]

[Panderner]

Desktop OpenGL is broken:

Mobile OpenGL is ok:

[jy95]

For me, OpenGL / Vulan / Direct3D 9 / Direct3D 11 are both broken on 1.13.1

[ghost]

@weihuoya what about this now.

[flexxarnnn]

I looked through previous versions of ppsspp and for me atleast the newest version to work right was ppsspp v1.11.3 when using the OpenGL renderer.

[jy95]

Confirmed - I tried on several versions but it only works on v1.1.3 with OpenGL renderer

[unknownbrackets]

#16049 will make this work on most devices other than those using Mali GPUs.

-[Unknown]

[Panderner]

Still has issue:
https://streamable.com/60wkiq

[ghost]

Still has issue: https://streamable.com/60wkiq

Can you upload your savestate in that area?

[Panderner]

Can you upload your savestate in that area?

At the beginning of Pursuit Force: Extreme Justice.

[unknownbrackets]

Thanks, I think I fixed the issue in the latest git - if not #16069 should mean less precision issues.

-[Unknown]

[ghost]

Confirm fixed via f8d29fd

The performance is so slow...

[hrydgard]

@Gamemulatorer Did the performance slow down with the fix, or was it already slow?

[ghost]

@Gamemulatorer Did the performance slow down with the fix, or was it already slow?

It was already slow :(
Maybe Snapdragon 450 is not good enough for this game.

[hrydgard]

Alright, that's good to know.

Yeah the game makes extremely heavy use of tessellation for the road surface, which is not fast in PPSSPP unfortunately.

Probably need to take another look at figuring out a way to make hardware tessellation work better and go fast. Using compute shaders instead of the wacky instancing trick we're currently using might help. Maybe some dynamic detail adjustment, too.

[ghost]

hardware tessellation makes this game a little faster in Vulkan.

But in opengl this game is super lag if hardware tessellation is on.

UCUS98703.ppdmp.zip

[unknownbrackets]

Note for any Mali users looking at the above and confused why it's still happening for you: this is only fixed on devices that support a hardware feature called "clip distance", which some GPUs (i.e. Mali) don't.

-[Unknown]