Microsoft says that 3D gaming today is a lie. While the techniques game designers use can make games on your screen look like they’re 3D, the rasterization process used ultimately only operates in two dimensions with 3D primitives mapped onto it via transformation matrices.

Things are changing with the introduction today of a DirectX 12

Source: Hot Hardware – Microsoft Introduces DirectX Raytracing Bringing Photorealistic, Movie-Quality 3D To Games