struct Attributes
{
    float4 positionOS : POSITION;
    UNITY_VERTEX_INPUT_INSTANCE_ID
};
struct Varyings
{
    float4 positionCS      : SV_POSITION;
    //UNITY_VERTEX_INPUT_INSTANCE_ID
    UNITY_VERTEX_OUTPUT_STEREO
};

Varyings vert(Attributes input)
{
    Varyings output = (Varyings)0;
    UNITY_SETUP_INSTANCE_ID(input);
    //UNITY_TRANSFER_INSTANCE_ID(input, output);
    UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(output);

    output.positionCS = TransformObjectToHClip(input.positionOS.xyz);
    return output;
}

half4 frag(Varyings input ) : SV_TARGET
{
    //UNITY_SETUP_INSTANCE_ID(input);
    UNITY_SETUP_STEREO_EYE_INDEX_POST_VERTEX(input);
    return 0;
}