struct Attributes
{
    float3 positionOS               : POSITION;
    UNITY_VERTEX_INPUT_INSTANCE_ID
};

struct Varyings
{
    float4 positionCS               : SV_POSITION;
    UNITY_VERTEX_OUTPUT_STEREO
};

Varyings DepthOnlyVertex(Attributes input)
{
    Varyings output = (Varyings)0;
    UNITY_SETUP_INSTANCE_ID(input);
    UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(output);

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

half4 DepthOnlyFragment(Varyings input) : SV_TARGET
{
    UNITY_SETUP_STEREO_EYE_INDEX_POST_VERTEX(input);
    return 0;
}