GPU Pro 6

3. Volumetric Fog and Lighting 227

float3 localLightDirection =

GetLocalLightDirection ( lightIndex , worldPosition );

lighting += GetLocalLightRadiance ( lightIndex , worldPosition )

GetPhaseFunction ( viewDirection , localLightDirection ,

g_VolumetricFogPhaseAnisotropy);

}

// Lighting sectio n END

// Finally , we apply some potentially non−white fog scattering albedo

color lighting = g_FogAlbedo ;

// Final in−scattering is product of outgoing radiance and scattering

// coefficients , while extinction is sum of scattering and absorption

float4 finalOutValue = float4 ( lighting scattering , scattering

+ absorption );

Listing 3.1. Pseudocode for calculati ...