在directx12中将深度缓冲区值读取回CPU
在directx12中将深度缓冲区值读取回CPU
提问于 2020-12-28 12:56:11
我希望将深度缓冲区的内容复制回CPU，以便能够读取它们。
我以以下方式创建深度缓冲区(视图)：
// Create the depth stencil view.
{
D3D12_DEPTH_STENCIL_VIEW_DESC depthStencilDesc = {};
depthStencilDesc.Format = DXGI_FORMAT_D32_FLOAT;
depthStencilDesc.ViewDimension = D3D12_DSV_DIMENSION_TEXTURE2D;
depthStencilDesc.Flags = D3D12_DSV_FLAG_NONE;
D3D12_CLEAR_VALUE depthOptimizedClearValue = {};
depthOptimizedClearValue.Format = DXGI_FORMAT_D32_FLOAT;
depthOptimizedClearValue.DepthStencil.Depth = 0.0f;
depthOptimizedClearValue.DepthStencil.Stencil = 0;
ThrowIfFailed(m_device->CreateCommittedResource(
&CD3DX12_HEAP_PROPERTIES(D3D12_HEAP_TYPE_DEFAULT),
D3D12_HEAP_FLAG_NONE,
&CD3DX12_RESOURCE_DESC::Tex2D(DXGI_FORMAT_D32_FLOAT, m_width, m_height, 1, 0, 1, 0, D3D12_RESOURCE_FLAG_ALLOW_DEPTH_STENCIL),
D3D12_RESOURCE_STATE_DEPTH_WRITE,
&depthOptimizedClearValue,
IID_PPV_ARGS(&m_depthStencil)
));
NAME_D3D12_OBJECT(m_depthStencil);
m_device->CreateDepthStencilView(m_depthStencil.Get(), &depthStencilDesc, m_dsvHeap->GetCPUDescriptorHandleForHeapStart());
}对于管道，我对深度缓冲区使用以下描述：
D3D12_DEPTH_STENCIL_DESC depthDesc;
ZeroMemory(&depthDesc, sizeof(D3D12_DEPTH_STENCIL_DESC));
depthDesc.DepthEnable = TRUE;
depthDesc.DepthWriteMask = D3D12_DEPTH_WRITE_MASK_ALL;
depthDesc.DepthFunc = D3D12_COMPARISON_FUNC_ALWAYS;
depthDesc.StencilEnable = FALSE;到目前为止，使用NSight，我可以看到，在完成呈现传递之后，正确的值将存储在深度缓冲区中。
现在，如果我使用: D3D12_HEAP_PROPERTIES readbackHeapProperties{ D3D12_HEAP_PROPERTIES}，我想将这些值读入CPU，在那里遇到问题；
堆类型readback我不能分配与深度缓冲区相同的描述的缓冲区。但是如果我使用CD3DX12_HEAP_PROPERTIES(D3D12_HEAP_TYPE_DEFAULT)，我以后就无法“映射”内存(根据microsoft文档https://learn.microsoft.com/en-us/windows/win32/direct3d12/readback-data-using-heaps)。
我要复制的其余部分类似于文档中的示例：
D3D12_RESOURCE_DESC desc;
ZeroMemory(&desc, sizeof(desc));
desc = m_depthStencil->GetDesc();
//D3D12_HEAP_PROPERTIES readbackHeapProperties{ CD3DX12_HEAP_PROPERTIES(D3D12_HEAP_TYPE_READBACK) };
//D3D12_RESOURCE_DESC readbackBufferDesc{ CD3DX12_RESOURCE_DESC::Buffer(500 * 500) };
D3D12_RESOURCE_DESC readbackBufferDesc = m_depthStencil->GetDesc();
ComPtr<ID3D12Resource> readbackBuffer;
ThrowIfFailed(m_device->CreateCommittedResource(
//&readbackHeapProperties,
&CD3DX12_HEAP_PROPERTIES(D3D12_HEAP_TYPE_DEFAULT),
D3D12_HEAP_FLAG_NONE,
&readbackBufferDesc,
D3D12_RESOURCE_STATE_COPY_DEST,
nullptr,
__uuidof(readbackBuffer),
&readbackBuffer));使深度缓冲区进入正确的状态。
{
D3D12_RESOURCE_BARRIER outputBufferResourceBarrier
{
CD3DX12_RESOURCE_BARRIER::Transition(
m_depthStencil.Get(),
D3D12_RESOURCE_STATE_DEPTH_WRITE,
D3D12_RESOURCE_STATE_COPY_SOURCE)
};
m_commandList->ResourceBarrier(1, &outputBufferResourceBarrier);
}
m_commandList->CopyResource(readbackBuffer.Get(), m_depthStencil.Get());
ThrowIfFailed(m_commandList->Close());
ID3D12CommandList* ppCommandLists[] = { m_commandList.Get() };
m_commandQueue->ExecuteCommandLists(_countof(ppCommandLists), ppCommandLists);
D3D12_RANGE readbackBufferRange{ 0, 500 * 500 }; // outputbuffer size = 500x500 = window size?
FLOAT* pReadbackBufferData{};
ThrowIfFailed(
readbackBuffer->Map
(
0,
&readbackBufferRange,
reinterpret_cast<void**>(&pReadbackBufferData)
)
);
D3D12_RANGE emptyRange{ 0, 0 };
readbackBuffer->Unmap
(
0,
&emptyRange
);将深度缓冲区转换为原始状态。
{
D3D12_RESOURCE_BARRIER outputBufferResourceBarrier
{
CD3DX12_RESOURCE_BARRIER::Transition(
m_depthStencil.Get(),
D3D12_RESOURCE_STATE_COPY_SOURCE,
D3D12_RESOURCE_STATE_DEPTH_WRITE)
};
m_commandList->ResourceBarrier(1, &outputBufferResourceBarrier);
}我会感谢你的帮助！
回答 1
Stack Overflow用户
回答已采纳
发布于 2020-12-28 19:36:02
在DirectX 12中，您不会创建与GPU资源格式相同的“readback”缓冲区。相反，您只需创建一个与源的字节数相同的一维缓冲区。
“诀窍”是，你需要有与原始资源相同的音高。
CD3DX12_HEAP_PROPERTIES readBackHeapProperties(D3D12_HEAP_TYPE_READBACK);
// Readback resources must be buffers
D3D12_RESOURCE_DESC bufferDesc = {};
bufferDesc.DepthOrArraySize = 1;
bufferDesc.Dimension = D3D12_RESOURCE_DIMENSION_BUFFER;
bufferDesc.Flags = D3D12_RESOURCE_FLAG_NONE;
bufferDesc.Format = DXGI_FORMAT_UNKNOWN;
bufferDesc.Height = 1;
bufferDesc.Width = srcPitch * m_height; // <<----
bufferDesc.Layout = D3D12_TEXTURE_LAYOUT_ROW_MAJOR;
bufferDesc.MipLevels = 1;
bufferDesc.SampleDesc.Count = 1;srcPitch是从原始资源获得的：
auto depthBufferDesc = CD3DX12_RESOURCE_DESC::Tex2D(DXGI_FORMAT_D32_FLOAT, m_width, m_height, 1, 0, 1, 0, D3D12_RESOURCE_FLAG_ALLOW_DEPTH_STENCIL);
UINT64 totalResourceSize = 0;
UINT64 fpRowPitch = 0;
UINT fpRowCount = 0;
m_device->GetCopyableFootprints(
&depthBufferDesc,
0,
1,
0,
nullptr,
&fpRowCount,
&fpRowPitch,
&totalResourceSize);
// Round up the srcPitch to multiples of 256
UINT64 srcPitch = (fpRowPitch + 255) & ~0xFFu;请参阅DirectX工具包中的DX12。
我还为那个Microsoft页面提交了一个编辑。它使用了一个缓冲区读取回缓冲区的示例，但没有提到读回资源始终是缓冲区的重要细节。
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/65477969
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