Import DataDoctor > Geometry Modification Tools > Modifying Surfaces > Trim, Extend, and Extrapolate > About the Extend Tool
  
About the Extend Tool
You can use the Extend tool to extend one or more contiguous one-sided edges of a quilt to a specified distance or up to a plane.
 
* You cannot use standard chain selection for extending. When selecting more than one edge to extend, you must use one-by-one chain selection.
In IDD you can extend a boundary of any quilt except merged or combined quilts. Extendable quilts in IDD are represented by one of the following nodes:
An active or base-level procedural node.
An active or base-level component node.
A base-level surface leaf node or active surface leaf node of a combine.
A surface subset of a component node when the component is not a single continuous quilt, and the selected subset represents a quilt.
A leaf surface, component, or procedure node of a combine node that has no connections to the other geometry of the combine node, that is, a combine node that only represents a logical grouping, not a close connection.
You can access the Extend tool, by selecting the boundary edge or edges of a quilt and clicking Edit > Extend on the Import DataDoctor ribbon tab.
You can extend a boundary of a quilt in one of the following ways:
Specify whether you want to measure the extension distance along the extended surface or along a selected datum plane.
Add measurement points to the selected boundary so you can vary the extension distance at different points along the boundary.
Extend a boundary in towards the quilt as well as away from it. When you extend a boundary in towards the quilt, the quilt surfaces are trimmed.
If you extend the quilt boundary by a specific distance, the following options are available on the Extend tab to further control the behavior of the extension:
Same—Creates the extension of the same type as the original surface. The original surface is extended past its selected boundary edge chain. This is the default.
Tangent—Creates the extension as a ruled surface that is tangent to the original surface.
Approximate—Creates the extension as a boundary blend between the boundary edges of the original surface and the edges of the extension.
During the extend operation, if you specify a Same surface, the nodes on the GTS Tree do not change. However, if you specify Tangent or Approximate surface and if IDD creates new surfaces to complete the extend operation, then a new node containing the original surfaces and the extended surfaces appear on the GTS Tree. If the quilt is represented by a component node or a surface subset of a component node, the new surface node or nodes are placed in the component. If the quilt is represented by a surface leaf node or a procedure node, a new combine node is created in its place, which contains the original leaf node and the new surface node or nodes.
In IDD the extend operation is not parametric. The extend operation does not result in the creation of a feature or operation that can be changed or deleted as in part mode. It causes a permanent change to the imported geometry. For example, if after extending up to a plane the relative position of the quilt and plane are changed, the extended geometry is not updated.