Current hardware does not necessarily implement all of the functionality that the Direct3D interface enables. Your program must test user's hardware and adjust its rendering strategies accordingly.
Many 3-D accelerator cards do not support diffuse iterated values as arguments to blending units. However, your program can introduce iterated color data when it performs texture blending.
Some 3-D hardware may not have a blending stage associated with the first texture. On these adapters, your application will need to perform blending in the second and third texture stages in the set of current textures.
Due to limitations in much of today's hardware, few display adapters can perform trilinear mipmap interpolation through the multiple texture blending interface offered by IDirect3DDevice3. Specifically, there is little support for setting the D3DTSS_MIPFILTER texture stage state to D3DTFP_LINEAR. Your application can use multipass texture blending to achieve the same effects, or degrade to the D3DTFP_POINT mipmap filter mode, which is widely supported.