The Edge Extend mode elongates open edges of a subdivision model. An open edge is an edge with only one adjacent face; this means that the cage mesh’s other adjacent faces have been completely deleted from the drawing using the Transform mode and the Delete key.
Cage mesh faces that are removed using Transform mode and the Delete key are permanently removed from the drawing and cannot be restored.
To extend an open edge of a subdivision model:
Select the subdivision object to edit.
Click the Edit Subdivision tool from the 3D Modeling tool set.
Alternatively, double-click the subdivision primitive object with the Selection tool to select the object and automatically activate the Edit Subdivision tool.
Click Edge Extend mode from the Tool bar.
As you move the cursor over the cage mesh, its edges are highlighted to indicate they can be modified. Only open edges can be extended. Edges that are not open do not highlight when the cursor moves over them.
Click on a cage mesh edge to extend, and move the cursor to change the object’s shape. As you move the cursor, the new shape previews.
Click to complete the extension.
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