Intermittent hook failure on Unity 6.3 (Fixed by -force-d3d12-debug)

[Kuan-Mi]

Description:
First of all, thanks for this awesome project! It’s a very helpful proof of concept for bindless rendering in Unity.
I am encountering an issue when using this plugin with Unity 6.3:
The cmdList hook only seems to trigger for a few random frames. In most frames, the bindless resources are not patched correctly.
Interestingly, if I launch Unity with the -force-d3d12-debug flag, the plugin works perfectly for every frame.

Environment:
Unity Version: 6.3
Graphics API: DX12
Platform: Windows
Any insights or suggestions on how to make the hook more stable in newer Unity versions would be greatly appreciated!

[Meetem]

Hello, thank you for the report. How do you know that they are not changed? I think I've seen some issues with black screen time to time when image is not cleared, probably related?

Probably the issue is that it calles different functions when not under debug mode, or some opeartions are just skipped... Not sure. I will need the description of the issue from your side.

[Kuan-Mi]

Thanks for the reply! Initially, the symptom was that objects using bindless shaders would be invisible most of the time, only flickering into view for a frame or two occasionally.

To investigate, I commented out all the code related to modifying the Root Signature and Pipeline State. I made it so that every hook function simply prints a log and then executes the original function as-is.

After comparing the behavior with and without the -force-d3d12-debug flag, I found that when the flag is not used, SetGraphicsRootDescriptorTable only triggers the hook and prints a log in a few rare frames. In the vast majority of frames, the log for SetGraphicsRootDescriptorTable is not printed at all.

[Meetem]

Yeah, it’s definitely related to the other bug Ive observed with similar symptoms. Would be interesting to investigate. AFAIK debug mode in driver can use alternative vtable, so that might be a hint.

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On Thu, 1 Jan 2026 at 05:01, MK ***@***.***> wrote: *MaZhengKe* left a comment (Meetem/DX12BindlessUnity#1) <#1 (comment)> Thanks for the reply! Initially, the symptom was that objects using bindless shaders would be invisible most of the time, only flickering into view for a frame or two occasionally. To investigate, I commented out all the code related to modifying the Root Signature and Pipeline State. I made it so that every hook function simply prints a log and then executes the original function as-is. After comparing the behavior with and without the -force-d3d12-debug flag, I found that when the flag is not used, SetGraphicsRootDescriptorTable only triggers the hook and prints a log in a few rare frames. In the vast majority of frames, the log for SetGraphicsRootDescriptorTable is not printed at all. — Reply to this email directly, view it on GitHub <#1 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AB2AF4VQIIGS2PYGEBQAWBL4ESLYDAVCNFSM6AAAAACQEXEQR2VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTOMBTGIZTEOBYHA> . You are receiving this because you commented.Message ID: ***@***.***>

[Kuan-Mi]

Even more strangely, this issue seems to be machine-specific. I've only encountered it on one of my computers, while it works perfectly fine on another. I will try testing it on more machines to see if I can consistently reproduce the issue.

[Meetem]

Yes, exactly, on my PC the behavior is different. Could you please tell me your specs including driver version?

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On Thu, 1 Jan 2026 at 05:05, MK ***@***.***> wrote: *MaZhengKe* left a comment (Meetem/DX12BindlessUnity#1) <#1 (comment)> Even more strangely, this issue seems to be machine-specific. I've only encountered it on one of my computers, while it works perfectly fine on another. I will try testing it on more machines to see if I can consistently reproduce the issue. — Reply to this email directly, view it on GitHub <#1 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AB2AF4TJO4BKZZVN73H6VK34ESMIHAVCNFSM6AAAAACQEXEQR2VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTOMBTGIZTMMZSGM> . You are receiving this because you commented.Message ID: ***@***.***>

[Kuan-Mi]

The issue mentioned above occurs on this PC: RTX 3070, Windows 11, GeForce Game Ready Driver 580.88.
On the other hand, my other PC (RTX 3060, also Win11) runs fine, though I can't recall the driver version.

Just updated to 591.59, yet the same flickering persists... (╥﹏╥)

[Kuan-Mi]

Just tested with Unity 6000.2.15 and it works fine. It looks like a change in 6000.3.2 triggered the problem (・・;). Anyway, I can work with this for now! Thanks for the help

[Meetem]

Can you look closer on 6000.2? Because in my experience (Ive tested before 6000.3) it was different, but the problem was there anyway, it was looking like black screen flickering (without vsync)

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On Thu, 1 Jan 2026 at 07:07, MK ***@***.***> wrote: *MaZhengKe* left a comment (Meetem/DX12BindlessUnity#1) <#1 (comment)> Just tested with Unity 6000.2.15 and it works fine. It looks like a change in 6000.3.2 triggered the problem (・・;). Anyway, I can work with this for now! Thanks for the help — Reply to this email directly, view it on GitHub <#1 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AB2AF4XED3QARHNKP34WUOT4ES2RRAVCNFSM6AAAAACQEXEQR2VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTOMBTGMYDQOJZGA> . You are receiving this because you commented.Message ID: ***@***.***>

[Kuan-Mi]

I've cloned the repository and tested it with Unity 6000.2.15. I turned off VSync, and everything works perfectly without any flickering, both in Editor and Play mode.

[Kuan-Mi]

Ah, I think I've found the root cause—it's RenderGraph.

When using version 6000.2.15, the default (Built-in) pipeline works fine, but it fails as soon as I switch to URP. If I change the settings to Compatibility Mode (which effectively disables RenderGraph), it displays correctly again.

However, version 6000.3 has already removed Compatibility Mode. It’s possible that the Built-in pipeline is now also using RenderGraph, which would explain why I'm seeing the exact same error after upgrading my Built-in project to 6000.3.

[Meetem]

This is rather peculiar bug... Don't even know how to fix that. Don't hesitate to give me pull request if you'll figure it out or give me a message if you found a real (from GFX API perspective) difference.

I will keep this issue open untill it's not fixed properly.

[Meetem]

I think I might have an idea, that probably in non-debug mode the driver just takes non-clear command list or something. Probably it's also related to the multithreading problems. Not sure, needs testing.

[Meetem]

Ok, it seems like Unity is recording "persistent" (more than one frame) command list bundles, and in those bundles they are not ensuring descriptor heaps setting, instead they bear it on the parent. This actually makes sense.