urho3d/SourceAssets/GLSLShaders/Material.xml

<shaders>
    <shader name="Material" type="vs">
        <option name="VCol" define="VERTEXCOLOR" />
        <variation name="" />
        <variation name="1VL" define="NUMVERTEXLIGHTS=1" />
        <variation name="2VL" define="NUMVERTEXLIGHTS=2" />
        <variation name="3VL" define="NUMVERTEXLIGHTS=3" />
        <variation name="4VL" define="NUMVERTEXLIGHTS=4" />
        <variation name="5VL" define="NUMVERTEXLIGHTS=5" />
        <variation name="6VL" define="NUMVERTEXLIGHTS=6" />
        <option name="" /> <!-- Dummy option to separate the two variation groups -->
        <variation name="" />
        <variation name="Skinned" define="SKINNED" />
    </shader>
    <shader name="Material" type="ps">
        <option name="Diff" define="DIFFMAP" />
        <option name="SpecMap" define="SPECMAP" />
        <option name="AlphaMask" define="ALPHAMASK" require="DIFFMAP" />
        <option name="VCol" define="VERTEXCOLOR" /> 
    </shader>
</shaders>