Ribbon Home tab > Layers panel > Layer Properties Layer Properties Icon Image Select New Layer in the Layer Properties dialog Layer Properties Dialog Image Input [layer name] e.g. DTMBoundary Exit Layer Properties dialog Select the pline boundary in the drawing space Apply pline to newly created layer Apply Boundary to Layer Image The boundary can now be hidden from view by toggling the freeze icon Freeze Icon Image For more information watch the video below: Create the Surface (WMV)