The Extend option is a pop-up menu that gives options to extend the end segments of line features. The pop-up menu is shown below. When extending features, you will initially be asked to specify the method of height calculation using the heights dialog box.
The End Point option allows you to move the end of a line feature by sketching a new position. You will be asked to indicate the end to extend and then the new position. Note that if you make the last segment of the indicated feature longer, a new point may be added to the end of the feature otherwise, the original point is moved to the new position.
The To Ref option allows you to extend the end of a feature until it meets another reference line feature segment. You will be asked to indicate the end of the feature to extend and then the segment to extend to. The co-ordinates of the intersection of the end segment and the indicated segment are then calculated. They are used to either create a new point or modify the existing point of the feature as necessary. Note that you can extend a line feature to a curved feature segment.
The Proj To Ref option allows you to project the last point of a feature perpendicularly onto a reference line feature segment and append a new point at those co-ordinates to the end of the feature being extended. The new end segment will be perpendicular to the reference segment.
The To Shape option allows you to extend the end of a line feature until meets a shape feature. You will be asked to indicate the end of the line feature to extend and then the shape feature to which you wish to extend to.
The By Dist option allows you to extend the end of a line feature by a specified distance. After you have indicated the end of the feature, a dialog to specify the distance by which the feature is to be extended will be displayed. If you enter a negative distance, the line feature will be shortened by that amount.
The Back 1mm option allows you to pull the end of a line feature back by 1mm. Indicate the end of the line feature and the length of the last segment will be adjusted accordingly.
The Merge option allows you to extend two line features until they meet each other. This is useful for picking up corner details which are obstructed from view. You are asked to indicate the ends of the two features to be extended and the intersection is calculated. If the last segment of a feature is made longer, a new point may be added to the end. If the last segment is made shorter, the end-point is moved to the intersection.
The Merge & Join option is fundamentally the same as the Extend Merge option. The difference is that the two indicated features are joined together using the code and direction of the first indicated feature.
Before Extend Merge
After Extend Merge