Lighting Calculation

float4 fvTotalAmbient  = fvAmbient * fvBaseColor;
float4 fvTotalDiffuse  = fvDiffuse * fNDotL * fvBaseColor;
float4 fvTotalSpecular = fvSpecular * pow( fRDotV, fSpecularPower );

return( saturate( fvTotalAmbient + fvTotalDiffuse + fvTotalSpecular ) );

Notes

• saturate() clamps the value between 0 and 1
• Do NOT use saturate in HDR (values above 1.0 are needed)
• Large capacity is possible due to texture compression
• Rim lighting technique: compute using the normal vector at the vertex stage