How to link descriptor table with multiple range to the compute shader - hlsl

Question

How to link one UAV descriptor table with a multiple ranges(u0,u1,u2) to the compute Shader
I can make a buffer for each of them and it would work but, I can't seem to figure out how to make it work using multiple ranges.
SetComputeRootDescriptorTable(RootParameterIndex,BaseDescriptor) Takes only these two inputs, This is how I attempted to compute it, so naturally I though I will link the three descriptors as commented below, but the app crash, so I commented the code that cause the crash.
ThrowIfFailed(m_pCommandAllocator->Reset());
ThrowIfFailed(m_pCommandList->Reset(m_pCommandAllocator.Get(), m_pPipelineState["CSPSO"].Get()));
m_pCommandList->SetComputeRootSignature(m_pCSRootSig.Get());
D3D12_GPU_DESCRIPTOR_HANDLE pComputeGPUHeapOffset= m_pCbvSrvDescriptorHeap->GetGPUDescriptorHandleForHeapStart();
ID3D12DescriptorHeap* ppHeaps[] = { m_pCbvSrvDescriptorHeap.Get() };
m_pCommandList->SetDescriptorHeaps(1, ppHeaps);
CD3DX12_GPU_DESCRIPTOR_HANDLE desc= CD3DX12_GPU_DESCRIPTOR_HANDLE(pComputeGPUHeapOffset, 0, m_nCbvSrvDescriptorSize);
m_pCommandList->SetComputeRootDescriptorTable(0, desc);
//uncommenting those causes crash even though each point to a different descriptor
//desc =CD3DX12_GPU_DESCRIPTOR_HANDLE(pComputeGPUHeapOffset, 1, m_nCbvSrvDescriptorSize);
//m_pCommandList->SetComputeRootDescriptorTable(0, desc);
//desc = CD3DX12_GPU_DESCRIPTOR_HANDLE(pComputeGPUHeapOffset, 2, m_nCbvSrvDescriptorSize);
//m_pCommandList->SetComputeRootDescriptorTable(0, desc);
m_pCommandList->Dispatch(1, 1,1);
Now This is written the rest of the code, First to define the descriptor table
CD3DX12_DESCRIPTOR_RANGE uavTable;
uavTable.Init(D3D12_DESCRIPTOR_RANGE_TYPE_UAV,
3,
0
);
CD3DX12_ROOT_SIGNATURE_DESC rootSigDesc(slotRootParameter.size(),
slotRootParameter.data(),
0,
nullptr
D3D12_ROOT_SIGNATURE_FLAG_ALLOW_INPUT_ASSEMBLER_INPUT_LAYOUT);
slotRootParameter[0].InitAsDescriptorTable(1, &uavTable, D3D12_SHADER_VISIBILITY_ALL);
Then to create the main buffer
ThrowIfFailed(m_pDevice->CreateCommittedResource(
&CD3DX12_HEAP_PROPERTIES(D3D12_HEAP_TYPE_DEFAULT),
D3D12_HEAP_FLAG_NONE,
&CD3DX12_RESOURCE_DESC::Buffer(paddedSize + sizeof(UINT),
D3D12_RESOURCE_FLAG_ALLOW_UNORDERED_ACCESS),
D3D12_RESOURCE_STATE_UNORDERED_ACCESS,
nullptr,
__uuidof(ID3D12Resource),
&MainBuffer
));
and the description for each section of the buffer that I want to link to U0,U1,U2 defined in the descriptor table as
D3D12_UNORDERED_ACCESS_VIEW_DESC uavDesc = {};
uavDesc.Format = DXGI_FORMAT_UNKNOWN;
uavDesc.ViewDimension = D3D12_UAV_DIMENSION_BUFFER;
uavDesc.Buffer.FirstElement = 0;
uavDesc.Buffer.NumElements = 3000;
uavDesc.Buffer.CounterOffsetInBytes = paddedSize;//aligned to 4096
uavDesc.Buffer.Flags = D3D12_BUFFER_UAV_FLAG_NONE;
uavDesc.Buffer.StructureByteStride = sizeof(Object1);
CD3DX12_CPU_DESCRIPTOR_HANDLE hDescriptor(m_pCbvSrvDescriptorHeap->GetCPUDescriptorHandleForHeapStart());
m_pDevice->CreateUnorderedAccessView(
MainBuffer.Get(),
MainBuffer.Get(),
&uavDesc,
hDescriptor);
uavDesc.Buffer.NumElements = 2000;
uavDesc.Buffer.FirstElement = 3000;
hDescriptor.Offset(1, m_nCbvSrvDescriptorSize);
uavDesc.Buffer.StructureByteStride = sizeof(Object2);
m_pDevice->CreateUnorderedAccessView(
MainBuffer.Get(),
MainBuffer.Get(),
&uavDesc,
hDescriptor);
uavDesc.Buffer.FirstElement = 5000;
hDescriptor.Offset(1, m_nCbvSrvDescriptorSize);
uavDesc.Buffer.StructureByteStride = sizeof(float);
m_pDevice->CreateUnorderedAccessView(
MainBuffer.Get(),
MainBuffer.Get(),
&uavDesc,
hDescriptor);
The paddedSize is the aligned sum of objects sizes multiplied by their buffer length
and a shader that output any values with structures like
RWStructuredBuffer <Object1> FirstBuffer:register(u0);
RWStructuredBuffer<Object2> SecondBuffer:register(u1);
RWStructuredBuffer<float> ThirdBuffer:register(u2);
Well when I pass dummy data in the first buffer I can see that the buffer is empty and when I output anything from the buffer after the shader is done it is also empty.
So what am I doing wrong?

Answer 1

CD3DX12_GPU_DESCRIPTOR_HANDLE desc= CD3DX12_GPU_DESCRIPTOR_HANDLE(pComputeGPUHeapOffset, 0, m_nCbvSrvDescriptorSize);
m_pCommandList->SetComputeRootDescriptorTable(0, desc);
//uncommenting those causes crash even though each point to a different descriptor
//desc =CD3DX12_GPU_DESCRIPTOR_HANDLE(pComputeGPUHeapOffset, 1, m_nCbvSrvDescriptorSize);
//m_pCommandList->SetComputeRootDescriptorTable(1, desc);
//desc = CD3DX12_GPU_DESCRIPTOR_HANDLE(pComputeGPUHeapOffset, 2, m_nCbvSrvDescriptorSize);
//m_pCommandList->SetComputeRootDescriptorTable(2, desc);
m_pCommandList->Dispatch(1, 1,1);
should give different indexes to root desc table enty in command list.