Material Alpha (Direct3D 9)

Alpha can also be supplied in a material. To enable material alpha, set the diffuse material render state so that the runtime will use the material diffuse color components rather than the vertex diffuse color components.

m_pd3dDevice->SetRenderState( D3DRS_DIFFUSEMATERIALSOURCE, D3DMCS_MATERIAL );

Initialize the material with an alpha value, and set the material before drawing.

D3DMATERIAL9 mtrl;
mtrl.Diffuse = mtrl.Ambient = mtrl.Specular = mtrl.Emissive = 
    D3DCOLORVALUE(255,0,0,0.5f)

m_pd3dDevice->SetMaterial(&mtrl);     

Related topics

Alpha Blending