Graphical issue on intel core ultra 5 (arch linux)

[kmwagnera]

Issue

I can start gothic 2 but there are graphical issues. Is there any way available to solve this issue?

Logs

logfile If I activate -v flag, I have very much cli output... maybe it helps? log.txt

[Try]

Hi, @kmwagnera !

I've looked into the log, seem to be 2 issues there:

If primitiveFragmentShadingRateMeshShader is VK_TRUE then primitiveFragmentShadingRate also needs to be VK_TRUE.

Issue here is engine requests all mesh-shader features that gpu claim to support, without accounting that other dependency has to be meet. Since no reason to care about VRS - just need to set primitiveFragmentShadingRateMeshShader to false.

Second:

vkCmdUpdateBuffer(): dstBuffer (VkBuffer 0xe5277c0000000317[]) was created with VK_BUFFER_USAGE_2_TRANSFER_SRC_BIT_KHR|VK_BUFFER_USAGE_2_UNIFORM_BUFFER_BIT_KHR|VK_BUFFER_USAGE_2_STORAGE_BUFFER_BIT_KHR|VK_BUFFER_USAGE_2_SHADER_DEVICE_ADDRESS_BIT_KHR but requires VK_BUFFER_USAGE_TRANSFER_DST_BIT.

Need to add VK_BUFFER_USAGE_TRANSFER_DST_BIT usage for, what seem to be uniform buffer.

[Try]

Can't quite fix it immediatly, as my windows-laptop died, but can do code-reviews.

[kmwagnera]

The issue happens on my archlinux system... If I can test anything, please come back to me and I will give it a try :) Thank you!

[Try]

my windows-laptop died The issue happens on my archlinux system...

I mean I have nothing that can run vulkan at the moment :D

[Try]

Reproduced and fixed part about primitiveFragmentShadingRateMeshShader

[AlexJakeGreen]

I also observe. Intel(R) Core(TM) Ultra 7 Arc Graphics Xe driver Linux 6.12.15 Build from 913dc793944ba2f58cd171960e0c7be6f60e8313 (Feb 22 15:12:50 2025 +0100)

https://github.com/user-attachments/assets/fc063953-f584-40d8-9bcb-7c8431370ec4

[Try]

Very interesting!

Those "rings", suggest to me that issue occurring only at the edge of light source. Presumably intel has some issue, when working with non-full quad.

@AlexJakeGreen If you take hero outside of Xardas'es tower, will game rendering normalize ?

[AlexJakeGreen]

@Try Yes, the rainbow lines disappear when I take the hero outside, but I notice it in caves, other buildings too, I guess any enclosed areas have this effect.

Outside, however, I see something else: it looks like a shadow (it is not a shadow but this name is the only thing I can link it with) quickly jumping from one tree to another.

Some rainbow lines don't hold a single color either — they change colors over time. I believe we’re dealing with two separate things here: one causes the rainbow lines, while the other is responsible for both the flickering shadow on the trees and the changing colors of the rainbows.

It's much clearer to watch the video rather than reading a lot of explanation:

https://github.com/user-attachments/assets/47ac9905-31d7-4058-9ed1-89ad4acd6a11

[Try]

If you have development environment, you may check: OpenGothic/shader/lighting/light.frag.

Shader has multiple early-outs in the main function:

  if(factor>1.0)
    discard;

  if(light<=0.0)
    discard;

  if(isShadow(cenPosition.xyz, ldir, cenPosition.w))
    discard;

I'm assuming that Intel has some problems when only part of quad is disarded

[AlexJakeGreen]

If I comment the third discard, then circles go away

-  if(isShadow(cenPosition.xyz, ldir, cenPosition.w))
-    discard;
+  //if(isShadow(cenPosition.xyz, ldir, cenPosition.w))
+  //  discard;

But trees still blink

https://github.com/user-attachments/assets/5b289575-520c-47a1-97b6-abf54464e13e

[Try]

@AlexJakeGreen are you playing with rayTracing? On RT-capable gpu it should be enable by default; will issue go away, if you run the game with -rt 0?

[AlexJakeGreen]

I confirm, that with -rt 0 circles are absent without -rt 0 circles are present

trees and shrubs blink in both cases

[AlexJakeGreen]

Hi, I found a workaround that helps avoid the flickering issue (it looks like a shadow jumping around objects in a circular pattern). I can get rid of it by launching the game with the -ms 0 parameter.

So, in order to play on intel ultra igpu, both -rt 0 and -ms 0 must be added -- and then I do not see issues.

@Try According to the main README,

    Ray tracing: setting affects only capable hardware, off by default for igpu's, add -rt 1 to enable

I guess, igpu auto-detection needs some improvement, so raytracing and meshlets are disabled automatically for this Intel Arc video card On my laptop the game engine detects it as GPU = Intel(R) Arc(tm) Graphics (MTL)

VGA compatible controller: Intel Corporation Meteor Lake-P [Intel Arc Graphics] (rev 08)
	Subsystem: Lenovo Device 50e9
	Kernel driver in use: i915
	Kernel modules: xe

[Try]

Hi,

I guess, igpu auto-detection needs some improvement,

There is no detection of a sort - engine takes this information directly from device property VkPhysicalDeviceProperties::deviceType. This is consistent with Intel-Arc marketing as dGPU.

And it's generally same thing about mesh-shader / ray-query. If GPU claim that it has support, and can't deliver - that's on Intel.