<OGRVRTDataSource>
<OGRVRTLayer name="test_vrt">
<SrcDataSource relativeToVRT="1">test_vrt.csv</SrcDataSource>
<GeometryType>wkbPoint25D</GeometryType>
<GeometryField encoding="PointFromColumns" x="POINT_X" y="POINT_Y" z="NUM"/>
</OGRVRTLayer>
</OGRVRTDataSource>