Shader-更复杂的光照-Unity的阴影

Pass {
        Name "ShadowCaster"
        Tags { "LightMode" = "ShadowCaster" }

  CGPROGRAM
  #pragma vertex vert
  #pragma fragment frag
  #pragma target 2.0
  #pragma multi_compile_shadowcaster
  #pragma multi_compile_instancing // allow instanced shadow pass for most of the shaders
  #include "UnityCG.cginc"

struct v2f {
    V2F_SHADOW_CASTER;
    UNITY_VERTEX_OUTPUT_STEREO
};

v2f vert( appdata_base v )
{
    v2f o;
    UNITY_SETUP_INSTANCE_ID(v);
    UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
    TRANSFER_SHADOW_CASTER_NORMALOFFSET(o)
    return o;
}

float4 frag( v2f i ) : SV_Target
{
    SHADOW_CASTER_FRAGMENT(i)
}
ENDCG

    }