Wrong Buffer Content with VK_EXT_descriptor_buffer

Developer Tools Nsight Graphics
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1

I use VK_EXT_descriptor_buffer with one big DescriptorBuffer, where all DescriptorSets are allocated in.
No normal DescriptorSet objects are used anywhere.

The Application runs normally with no Validation Errors.

I wanted to debug a frame but found an issue with the correctness of buffer contents:

I created a buffer with 4 bytes (1 uint).
This buffer is cleared to 0 and then bound to a compute shader, which writes to it.
Then the buffer is used as a IndirectCount buffer for a DrawIndexedIndirectCount command.
NSight correctly tracks the filling with 0, but fails to detect that it was written to in the compute shader.

This seems to happen with all buffers, that are bound via DescriptorBuffer.

What additional settings do I need to set, when I want to use NSight with DescriptorBuffers?
I already checked that VkPhysicalDeviceDescriptorBufferFeaturesEXT.descriptorBufferCaptureReplay is supported on my device and I requested it on device creation.

NSight Version 2024.2.0.0
Vulkan Instance Version: 1.3.280

Thanks in advance.

2

Hi felix.richter,

Thank you for using Nsight Graphics and providing your feedback. We are sorry for any inconvenience you have encountered. It looks like an issue, but could you please provide a simple example that would allow us to reproduce the issue? This will help us in investigating and resolving the problem more efficiently.

Thanks
An

3

Hi An,

NSight seems to only track the first Descriptor in a DescriptorSet, but the second one redirects to the first one.

I reproduced it in a small C# Application (with Silk.Net as a Wrapper for Vulkan).

I can’t share it publicly though.

Do you have some private location, where I can share it with you non-publicly?