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DX11 Losing Instance Buffer Data

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I’ve got a function that basically creates different instance buffers into an array for me to use in my DrawIndexedInstanced call.

But when I pass the vertex buffer and instance buffer through to my shader, my instance data is completely lost when the shader goes to use it, so none of my objects are being relocated and are thus all rendering in the same place.

I’ve been looking at this for hours and literally cannot find anything that is helpful.

Creating the Vertex shader input layout:

D3D11_INPUT_ELEMENT_DESC solidColorLayout[] =
{
    //Vertex Buffer
    { "POSITION", 0, DXGI_FORMAT_R32G32B32_FLOAT, 0, 0, D3D11_INPUT_PER_VERTEX_DATA, 0 },
    { "TEXCOORD", 0, DXGI_FORMAT_R32G32_FLOAT, 0, 12, D3D11_INPUT_PER_VERTEX_DATA, 0 },

    //Instance buffer
    { "INSTANCEPOS", 0, DXGI_FORMAT_R32G32B32_FLOAT, 1, 0, D3D11_INPUT_PER_INSTANCE_DATA, 1 },
    { "INSTANCEROT", 0, DXGI_FORMAT_R32G32B32_FLOAT, 1, 12, D3D11_INPUT_PER_INSTANCE_DATA, 1 },
    { "INSTANCESCA", 0, DXGI_FORMAT_R32G32B32_FLOAT, 1, 24, D3D11_INPUT_PER_INSTANCE_DATA, 1 },
    { "INSTANCETEX", 0, DXGI_FORMAT_R32_FLOAT, 1, 36, D3D11_INPUT_PER_INSTANCE_DATA, 1 }
};

Creating an instance buffer (called multiple times per frame, to create all necessary buffers):

void GameManager::CreateInstanceBuffer(ID3D11Buffer** buffer, Mesh* mesh, std::vector<Instance> instances)
{

    D3D11_BUFFER_DESC instBuffDesc;
    ZeroMemory(&instBuffDesc, sizeof(instBuffDesc));

    instBuffDesc.Usage = D3D11_USAGE_DEFAULT;
    instBuffDesc.ByteWidth = sizeof(Instance) * instances.size();
    instBuffDesc.BindFlags = D3D11_BIND_VERTEX_BUFFER;
    instBuffDesc.CPUAccessFlags = 0;
    instBuffDesc.MiscFlags = 0;
    instBuffDesc.StructureByteStride = 0;

    int i = sizeof(Instance);

    D3D11_SUBRESOURCE_DATA instData;
    ZeroMemory(&instData, sizeof(instData));

    instData.pSysMem = &instances;
    instData.SysMemPitch = 0;
    instData.SysMemSlicePitch = 0;

    CheckFailWithError(dxManager.GetDevice()->CreateBuffer(&instBuffDesc, &instData, buffer),
        "An error occurred whilst building an instance buffer",
        "[GameManager]");


    meshBuffers.push_back(mesh->GetBuffer(VERTEX_BUFFER));
}

The draw command:

dxManager.GetContext()->DrawIndexedInstanced(instanceIndexCounts[buffer], instanceCounts[buffer], 0, 0, 0);

I’ve used the graphics debugger built into Visual Studio. Initially it appeared to be assigning variables in the Vertex shader back to front, however removing APPEND_ALIGNED_ELEMENT from the AlignedByteOffset has fixed that, however the per-instance data seems to be corrupt and is not getting recieved.

If there is anything else you need let me know and I’ll update the post as necessary.


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