Microsoft® Direct3D® enables one shading mode to be selected at a time. By default, Gouraud shading is selected. In C++, you can change the shading mode by calling the IDirect3DDevice8::SetRenderState method. Set the State parameter to D3DRS_SHADEMODE. The State parameter must be set to a member of the D3DSHADEMODE enumeration. The following sample code examples illustrate how the current shading mode of a Direct3D application can be set to flat or Gouraud shading mode.

// Set to flat shading.
// This code example assumes that pDev is a valid pointer to 
// an IDirect3DDevice8 interface.
hr = pDev->SetRenderState(D3DRS_SHADEMODE, D3DSHADE_FLAT);
if(FAILED(hr))
{
    // Code to handle the error goes here.
}
 
// Set to Gouraud shading. This is the default for Direct3D.
hr = pDev->SetRenderState(D3DRS_SHADEMODE,
                            D3DSHADE_GOURAUD);
if(FAILED(hr))
{
    // Code to handle the error goes here.
}