To Extrapolate a Surface
1. Click Restyle > Extend. The Extrapolate tab opens.
2. Select the surface for extrapolating. The selected surface is highlighted.
3. Select and drag the edge from which to extrapolate the surface. The surface is extrapolated along the selected edge.
4. Optionally, to stretch a surface, change the Extend mode on the tab from Extrapolate to Stretch.
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When attempting to extrapolate an already merged surface, the surface intersections are temporarily removed. Once the extrapolation is over, Restyle restores the surface intersections.