Direct3d is actually a part of DirectX . Direct 3d , which updated along with the version of DirectX , such as DirectX9.0 , 9.0b , 8.1 . .. etc .

Updated version will include newer technology for graphic enchancement , such as the newest Shader Model 3.0 (include both Pixel Shader and vertex shader 3.0) with 9.0c .

Direct 8 comes with Pixel Shader , the best technology I ever see , along with bump mapping .

Keep in mind that to display this technology , your GPU must support it in hardware also .