[Bug]: enable_accelerated_osr renders nothing

[lublak]

What happened?

Currently it renders an empty rectangle (transparent)

How to reproduce

I think this will hard to reproduce because there can be some hardware differences.

Could it be this "failed" queue?

[AcceleratedOSR/Vulkan] Graphics family has 16 queues, trying queue index 1
[AcceleratedOSR/Vulkan] Preferred queue not available, falling back to queue 0

For me its also fine to render software based!

Environment

• Godot: 4.6
• godot-cef: 1.11.0
• endeavouros/arch

Logs or screenshots (optional)

Godot Engine v4.6.stable.arch_linux - https://godotengine.org
Vulkan 1.4.325 - Forward+ - Using Device #0: NVIDIA - NVIDIA GeForce RTX 4090

[AcceleratedOSR] Detected render backend: Vulkan (driver: vulkan)
[AcceleratedOSR] Detected render backend: Vulkan (driver: vulkan)
[AcceleratedOSR] Detected render backend: Vulkan (driver: vulkan)
[CefInit] Startup summary: backend=Vulkan, accelerated_osr_supported=true, reason=backend Vulkan supports accelerated OSR, remote_debugging=true, remote_port=9229, cache_size_mb=0
[AcceleratedOSR/Vulkan] Godot GPU: vendor=0x10de, device=0x2684, name=NVIDIA GeForce RTX 4090
[CefInit] Godot GPU: vendor=0x10de, device=0x2684 - will pass to CEF subprocesses
[GodotCef] Production security baseline: godot_cef/security/allow_insecure_content=false, godot_cef/security/ignore_certificate_errors=false, godot_cef/security/disable_web_security=false, godot_cef/advanced/custom_command_line_switches should not include insecure switches.
[AcceleratedOSR] Detected render backend: Vulkan (driver: vulkan)
[AcceleratedOSR] Detected render backend: Vulkan (driver: vulkan)
[CefTexture] Creating browser in accelerated rendering mode
[AcceleratedOSR] Detected render backend: Vulkan (driver: vulkan)
[AcceleratedOSR/Vulkan] Graphics family has 16 queues, trying queue index 1
[AcceleratedOSR/Vulkan] Preferred queue not available, falling back to queue 0
[AcceleratedOSR/Vulkan] Using separate queue (family=0, index=1) for texture copies
[AcceleratedOSR/Linux] Using Vulkan backend with DMA-BUF

Additional context (optional)

No response

Before submitting

• I have searched existing issues to make sure this isn't a duplicate

[dsh0416]

I think I havn't manually tested the linux version with OSR for a while, I would fix it soon.

[dsh0416]

Would you please check if v1.12.1 has fixed the issue? Thank you.

[lublak]

@dsh0416 still empty 🥹

Godot Engine v4.6.stable.arch_linux - https://godotengine.org
Vulkan 1.4.325 - Forward+ - Using Device #0: NVIDIA - NVIDIA GeForce RTX 4090

[AcceleratedOSR] Detected render backend: Vulkan (driver: vulkan)
[AcceleratedOSR] Detected render backend: Vulkan (driver: vulkan)
[AcceleratedOSR] Detected render backend: Vulkan (driver: vulkan)
[CefInit] Startup summary: backend=Vulkan, accelerated_osr_supported=true, reason=backend Vulkan supports accelerated OSR, remote_debugging=true, remote_port=9229, cache_size_mb=0
[AcceleratedOSR/Vulkan] Godot GPU: vendor=0x10de, device=0x2684, name=NVIDIA GeForce RTX 4090
[CefInit] Godot GPU: vendor=0x10de, device=0x2684 - will pass to CEF subprocesses
[GodotCef] Production security baseline: godot_cef/security/allow_insecure_content=false, godot_cef/security/ignore_certificate_errors=false, godot_cef/security/disable_web_security=false, godot_cef/advanced/custom_command_line_switches should not include insecure switches.
[AcceleratedOSR] Detected render backend: Vulkan (driver: vulkan)
[AcceleratedOSR] Detected render backend: Vulkan (driver: vulkan)
[CefTexture2D] Creating browser in accelerated rendering mode
[AcceleratedOSR] Detected render backend: Vulkan (driver: vulkan)
[AcceleratedOSR/Vulkan] Graphics family has 16 queues, trying queue index 1
[AcceleratedOSR/Vulkan] Preferred queue not available, falling back to queue 0
[AcceleratedOSR/Vulkan] Using shared graphics queue - may have sync issues under load
[AcceleratedOSR/Linux] Using Vulkan backend with DMA-BUF
--- Debugging process stopped ---

[dsh0416]

I replicated the error, and it is really strange. It looks like a commit from about 1 month ago breaks the linux vulkan impl totally, and I am investigating it.

[dsh0416]

After two months of investigating, it looks that the bug is driver-related, it is raising different issues on different GPUs. I could totally confused and I may need more time for investigating. So confusing.

[CM-apu]

Hi,
aren't there any update on this issue? I just created a new project with GodotCEF on Godot 4.6.2. As explained in the documentation, I just created a Control Scene with the basic script and it renders nothing on screen.

Environment

Godot: 4.6.2
godot-cef: 1.13
Debian 13
Intel iGPU: Intel - Intel(R) HD Graphics 620 (KBL GT2)

Logs or screenshots (optional)

Godot Engine v4.6.2.stable.official.71f334935 - https://godotengine.org
Vulkan 1.4.305 - Forward+ - Using Device #0: Intel - Intel(R) HD Graphics 620 (KBL GT2)

[AcceleratedOSR] Detected render backend: Vulkan (driver: vulkan)
[AcceleratedOSR] Detected render backend: Vulkan (driver: vulkan)
[AcceleratedOSR] Detected render backend: Vulkan (driver: vulkan)
[CefInit] Startup summary: backend=Vulkan, accelerated_osr_supported=true, reason=backend Vulkan supports accelerated OSR, remote_debugging=true, remote_port=9229, cache_size_mb=0
[AcceleratedOSR/Vulkan] Godot GPU: vendor=0x8086, device=0x5916, name=Intel(R) HD Graphics 620 (KBL GT2)
[CefInit] Godot GPU: vendor=0x8086, device=0x5916 - will pass to CEF subprocesses
[GodotCef] Production security baseline: godot_cef/security/allow_insecure_content=false, godot_cef/security/ignore_certificate_errors=false, godot_cef/security/disable_web_security=false, godot_cef/advanced/custom_command_line_switches should not include insecure switches.

Thank you.

[lublak]

@CM-apu the update just was one week ago

After two months of investigating, it looks that the bug is driver-related, it is raising different issues on different GPUs. I could totally confused and I may need more time for investigating. So confusing.

@dsh0416

I'm not very familiar with DMA-BUF.
Is there any way I can help with this? What have you found out so far? Would it help if I tested it on a different graphics card?
Is there anything specific you'd like me to test for you?

[dsh0416]

I spent another month on debugging this issue. I got more confused. On Intel Arc B580 and Arc A770, it works perfectly without any code changes. But on NVIDIA 4090 3070 and on 4060 mobile, it fails by keeping returning a 0x0 empty texture with a driver after 535. Before 535, it keeps raising errors that not returning any dma-buf infomation at all. But on integrated GPU like intel HD 630, it is NOT WORKING AGAIN! From the debug info, I see all of these not working GPUs have gpu acceleration enabled from the CEF side and it is not in the CEF's acceleration blocklist…

[dsh0416]

Now I've confirmed it works perfectly on intel Arc GPUs. It doesn't work properly on intel old integrated GPUs due to the limitation of the Vulkan support. We might need some blocklist to disable the feature on unsupported GPUs. But on NVIDIA GPUs, it should support DMA-BUF, but it 100% fails for now for some unknown reasons.

[dsh0416]

But it shows that NVIDIA should have fixed the DMA-BUF support since 2023, so that there must be some other hidden issues.

[lublak]

@dsh0416 im also in the research, i found something about EGLImage?
So, generally speaking, there seems to be a slight difference between the open standard used by AMD and Intel and the standard used by Nvidia. If I’ve understood correctly. But EGL is OpenGL? I need more research!

[dsh0416]

@dsh0416 im also in the research, i found something about EGLImage? So, generally speaking, there seems to be a slight difference between the open standard used by AMD and Intel and the standard used by Nvidia. If I’ve understood correctly. But EGL is OpenGL? I need more research!

Yes. First sharing a texture between processes is a OS feature. On windows, it is shared by HANDLE; on macOS, it is IOSurface; on Linux, it is DMA-BUF. Unlike Windows or macOS, Linux doesn't enforce the GPU driver to support DMA-BUF. It is optional through extension. There is a very similar extension in both EGL and Vulkan. EGL is for OpenGL, you are correct. When the GPU provider claimed they have this extension available, we need to manually register it in OpenGL or Vulkan API, then we could share the texture properly. Here is the issue, on NVIDIA GPUs, especially for proprietary driver, the extension is available and registerable, but it is returning 0x0 blank image. I've also made a very small OpenGL example with EGL, which is returning a very similar issue.