Can you clarify what you're trying to do? Are you trying to make a sphere map? I know Valve used them in and early iteration of the Source engine and theres code for generating sphere maps inside VTFLib (see. the CVTFFile::GenerateSphereMap() which I wrote).
You can load your VTF Cubemap and use GetData() to get a pointed to each face to pass to the GenerateSphereMap function. That way you wouldn't need to extract the faces.
Can you clarify what you're trying to do? Are you trying to make a sphere map? I know Valve used them in and early iteration of the Source engine and theres code for generating sphere maps inside VTFLib (see. the CVTFFile::GenerateSphereMap() which I wrote).
You can load your VTF Cubemap and use GetData() to get a pointed to each face to pass to the GenerateSphereMap function. That way you wouldn't need to extract the faces.