(Intel GPU) Any suggetions on how to debug why this happens?

KynikossDragonn · Post by **KynikossDragonn** » Sat Oct 02, 2021 11:48 am

So I've been having this happen and I'd like to try to understand why it's happening and why it's always consistently this triangle that's messing up under these same conditions:

(not pictured, it's wobbling and distorting every single frame chaotically until I look back up)

I have this same issue cropping up in various other maps too, it's always a single triangle not the entire "quad" that messes up, when it happens in a certain map it's guaranteed to always happen in that spot I find it in, and I have no idea the rhyme of reason why this is so reproducible.

I'm on open source drivers but not debug builds of them, I suppose I should try and locally build debug versions and LD_PRELOAD those into gzdoom on launch huh?

Code: Select all

Extended renderer info (GLX_MESA_query_renderer):
    Vendor: Intel (0x8086)
    Device: Mesa Intel(R) Iris(R) Pro Graphics 580 (SKL GT4) (0x193b)
    Version: 21.2.3
    Accelerated: yes
    Video memory: 3072MB
    Unified memory: yes
    Preferred profile: core (0x1)
    Max core profile version: 4.6
    Max compat profile version: 4.6
    Max GLES1 profile version: 1.1
    Max GLES[23] profile version: 3.2

Code: Select all

GPU0:
VkPhysicalDeviceProperties:
---------------------------
        apiVersion        = 4202678 (1.2.182)
        driverVersion     = 88088579 (0x5402003)
        vendorID          = 0x8086
        deviceID          = 0x193b
        deviceType        = PHYSICAL_DEVICE_TYPE_INTEGRATED_GPU
        deviceName        = Intel(R) Iris(R) Pro Graphics 580 (SKL GT4)
        pipelineCacheUUID = fa757e10-099a-6710-3cd2-61f52f114045

I've asked someone if gzdoom has any kind of verbosity when it comes to it's rendering methods so I could try and narrow down the conditions for triggering this graphical error, but I've been told there are none...

Post by **_mental_** » Sat Oct 02, 2021 1:10 pm

For Vulkan, toggle vk_debug CVAR to enable validation layers support. Of course, you need to have them installed first. Vulkan SDK is the most obvious way to get them.

KynikossDragonn · Post by **KynikossDragonn** » Sat Oct 02, 2021 2:03 pm

Ah, okay. Since the same problem happens even in Vulkan, I'm going to hope something turns up there, but I guess there's no easy way to debug the OpenGL renderer?

Post by **_mental_** » Sun Oct 03, 2021 12:07 am

It depends on your "debug the renderer" definition. Try https://renderdoc.org/ or https://github.com/apitrace/apitrace .

KynikossDragonn · Post by **KynikossDragonn** » Sun Oct 03, 2021 4:12 am

_mental_ wrote:It depends on your "debug the renderer" definition.

Oh, of course what I'm after basically is trying to narrow down, and capture the exact state and series of calls that results in that rendering bug happening on here, so I could hope someone that works on these drivers will take a closer look at and figure out how to fix or work around the problem. It's just bizarre to me this happens so easily under GZDoom but not under most other things.

ZDoom