Pass
        {
            Name "ShadowCaster"
            Tags{"LightMode" = "ShadowCaster"}
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #pragma multi_compile_shadowcaster
            #include "UnityCG.cginc" 
            struct v2f
            {
                V2F_SHADOW_CASTER;
            }; 
            v2f vert( appdata_base  v)
            {
                v2f o;
                TRANSFER_SHADOW_CASTER_NORMALOFFSET(o)
                return o;
            }
            float4  frag(v2f i):SV_Target
            {
                SHADOW_CASTER_FRAGMENT(i)
            }
            ENDCG
        }