D3D11: Creating a cube map from 6 images

Question

How do I create a cube map in D3D11 from 6 images? All the examples I've found use only one .dds. Specifically, how do I upload individual faces of the cube texture?

Spears

Answer 1

It works like this:

D3D11_TEXTURE2D_DESC texDesc;
texDesc.Width = description.width;
texDesc.Height = description.height;
texDesc.MipLevels = 1;
texDesc.ArraySize = 6;
texDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
texDesc.CPUAccessFlags = 0;
texDesc.SampleDesc.Count = 1;
texDesc.SampleDesc.Quality = 0;
texDesc.Usage = D3D11_USAGE_DEFAULT;
texDesc.BindFlags = D3D11_BIND_SHADER_RESOURCE;
texDesc.CPUAccessFlags = 0;
texDesc.MiscFlags = D3D11_RESOURCE_MISC_TEXTURECUBE;

D3D11_SHADER_RESOURCE_VIEW_DESC SMViewDesc;
SMViewDesc.Format = texDesc.Format;
SMViewDesc.ViewDimension = D3D11_SRV_DIMENSION_TEXTURECUBE;
SMViewDesc.TextureCube.MipLevels =  texDesc.MipLevels;
SMViewDesc.TextureCube.MostDetailedMip = 0;

D3D11_SUBRESOURCE_DATA pData[6];
std::vector<vector4b> d[6]; // 6 images of type vector4b = 4 * unsigned char

for (int cubeMapFaceIndex = 0; cubeMapFaceIndex < 6; cubeMapFaceIndex++)
{   
    d[cubeMapFaceIndex].resize(description.width * description.height);

    // fill with red color  
    std::fill(
        d[cubeMapFaceIndex].begin(), 
        d[cubeMapFaceIndex].end(), 
        vector4b(255,0,0,255));

    pData[cubeMapFaceIndex].pSysMem = &d[cubeMapFaceIndex][0];// description.data;
    pData[cubeMapFaceIndex].SysMemPitch = description.width * 4;
    pData[cubeMapFaceIndex].SysMemSlicePitch = 0;
}

HRESULT hr = renderer->getDevice()->CreateTexture2D(&texDesc, 
    description.data[0] ? &pData[0] : nullptr, &m_pCubeTexture);
assert(hr == S_OK);

hr = renderer->getDevice()->CreateShaderResourceView(
    m_pCubeTexture, &SMViewDesc, &m_pShaderResourceView);
assert(hr == S_OK);

This creates six "red" images, for the CubeMap.

Darcydarda

What if you want to fill the cubemap data with a texture from file instead of a red color here ? – Devoe

Note : use an image loader like openil.sourceforge.net or cimg.eu to initialize your textures CPU side. – Devoe

How to load texture data: bitbucket.org/Anteru/d3d12sample/src/… – Darcydarda

Answer 2

I know this question is old, and there is already a solution.

Here is a code example that loads 6 textures from disk and puts them together as a cubemap:

Precondition:

ID3D11ShaderResourceView* srv = 0;
ID3D11Resource* srcTex[6];

Pointer to a ShaderResourceView and an array filled with the six textures from disc. I use the order right, left, top, bottom, front, back.

// Each element in the texture array has the same format/dimensions.
D3D11_TEXTURE2D_DESC texElementDesc;
((ID3D11Texture2D*)srcTex[0])->GetDesc(&texElementDesc);

D3D11_TEXTURE2D_DESC texArrayDesc;
texArrayDesc.Width = texElementDesc.Width;
texArrayDesc.Height = texElementDesc.Height;
texArrayDesc.MipLevels = texElementDesc.MipLevels;
texArrayDesc.ArraySize = 6;
texArrayDesc.Format = texElementDesc.Format;
texArrayDesc.SampleDesc.Count = 1;
texArrayDesc.SampleDesc.Quality = 0;
texArrayDesc.Usage = D3D11_USAGE_DEFAULT;
texArrayDesc.BindFlags = D3D11_BIND_SHADER_RESOURCE;
texArrayDesc.CPUAccessFlags = 0;
texArrayDesc.MiscFlags = D3D11_RESOURCE_MISC_TEXTURECUBE;

ID3D11Texture2D* texArray = 0;
if (FAILED(pd3dDevice->CreateTexture2D(&texArrayDesc, 0, &texArray)))
    return false;

// Copy individual texture elements into texture array.
ID3D11DeviceContext* pd3dContext;
pd3dDevice->GetImmediateContext(&pd3dContext);
D3D11_BOX sourceRegion;

//Here i copy the mip map levels of the textures
for (UINT x = 0; x < 6; x++)
{
    for (UINT mipLevel = 0; mipLevel < texArrayDesc.MipLevels; mipLevel++)
    {
        sourceRegion.left = 0;
        sourceRegion.right = (texArrayDesc.Width >> mipLevel);
        sourceRegion.top = 0;
        sourceRegion.bottom = (texArrayDesc.Height >> mipLevel);
        sourceRegion.front = 0;
        sourceRegion.back = 1;

        //test for overflow
        if (sourceRegion.bottom == 0 || sourceRegion.right == 0)
            break;

        pd3dContext->CopySubresourceRegion(texArray, D3D11CalcSubresource(mipLevel, x, texArrayDesc.MipLevels), 0, 0, 0, srcTex[x], mipLevel, &sourceRegion);
    }
}

// Create a resource view to the texture array.
D3D11_SHADER_RESOURCE_VIEW_DESC viewDesc;
viewDesc.Format = texArrayDesc.Format;
viewDesc.ViewDimension = D3D11_SRV_DIMENSION_TEXTURECUBE;
viewDesc.TextureCube.MostDetailedMip = 0;
viewDesc.TextureCube.MipLevels = texArrayDesc.MipLevels;

if (FAILED(pd3dDevice->CreateShaderResourceView(texArray, &viewDesc, &srv)))
    return false;

If anyone reads this question again, maybe try this one. Warning: this function is not threadsafe, because i have to use the deviceContext.

Ambiguity

Is this correct? I thought I have to set MiscFlags to D3D11_RESOURCE_MISC_TEXTURECUBE – Hundredth

yeah you're right, in my original code i had a condition: texArrayDesc.MiscFlags = isCubeMap ? D3D11_RESOURCE_MISC_TEXTURECUBE : 0; isCubeMap is a function parameter to create the texture, i will edit my answer. THX – Ambiguity