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DX12 [D3D12] Texture Upload Heap

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I am trying to render a textured quad.  If I just use a heap of type D3D12_HEAP_TYPE_UPLOAD then I can see the texture perfectly.  But I want to use a heap of type D3D12_HEAP_TYPE_DEFAULT and use a D3D12_HEAP_TYPE_UPLOAD to copy the data to it.

 

So everything works when I call:

 

  • CreateCommittedResource(&CD3DX12_HEAP_PROPERTIES(D3D12_HEAP_TYPE_UPLOAD)... IID_PPV_ARGS(&textureUpload));
  • textureUpload->WriteToSubresource(...
  • device->CreateDescriptorHeap(...
  • device->CreateShaderResourceView(textureUpload.Get()...

 

With this I see my texture just fine.  But when I try to do it like so, I just get a black quad:

 

  • CreateCommittedResource(&CD3DX12_HEAP_PROPERTIES(D3D12_HEAP_TYPE_DEFAULT)... IID_PPV_ARGS(&texture));
  • CreateCommittedResource(&CD3DX12_HEAP_PROPERTIES(D3D12_HEAP_TYPE_UPLOAD)... IID_PPV_ARGS(&textureUpload));
  • UpdateSubresources(commandList, texture.Get(), textureUpload.Get()...
  • commandList->ResourceBarrier(...
  • device->CreateDescriptorHeap(...
  • device->CreateShaderResourceView(texture.Get()...

 

Is there something blatantly wrong that I'm doing??

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I think I came across a similar issue when trying to use textures in a pre-release version of D3D12 a few months back. You can read the details on page 4 of the D3D12 documentation thread, although it might not be relevant.

Assuming you're using VS2015, you can use the graphics debugger to capture a frame and inspect your "texture" default heap committed resource. If it's the same problem then the texture mip levels will be garbled and/or black.

The problem was that directly copying subresources from an upload heap buffer to a default heap buffer leaves texture subresources unable to be correctly accessed by the GPU from a default heap, and I believe (though I may be wrong) this is because the GPU expects default heap texture data to be laid out in a hardware specific way.

The solution was rather than using generic update/copy/writesubresource methods when copying textures to a default heap (as you would for non-texture buffers), you have to copy texture subresource data using CommandList::CopyTextureRegion. That way the GPU copies the subresource data to the default heap with the layout the hardware expects for texture accesses from GPU-only memory.

Hope it helps, though if anyone knows it's changed since, I'd be glad of the updated info also. smile.png

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The graphics debugger is awesome.  Absolutely awesome.  Unfortunately for me it just confirms what I'm seeing; the CBV_SRV_UAV Resource is all black.  Proper size and format, but every pixel is (0, 0, 0, 0).

 

Further, I'm using UpdateSubresources, a function out of the d3dx12.h header that they included with the samples.  It calls CommandList::CopyTextureRegion to perform the upload.

 

Perhaps it's important that I'm not generating a mipmap chain?  I can't see why it would work with D3D12_HEAP_TYPE_UPLOAD and not D3D12_HEAP_TYPE_DEFAULT though...

 

 

**EDIT**

 

Got it.  I needed to call ID3D12CommandQueue::ExecuteCommandLists before I went into my rendering loop.  In retrospect this seems obvious; without telling the GPU to execute the CopyTextureRegion command, it will get thrown away when I call ID3D12GraphicsCommandList::Reset prior to submitting my rendering calls.

 

Guess I've gotta keep wrapping my head around the methodology of DX12.  Thanks for the help!

Edited by Funkymunky

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