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2.2.7.5 Cornu Track Pins

XTrackCAD Cornu can have "track pins" added that constrain the track to pass through those points in addition to meeting the end-conditions. This allows the track to be skewed or slewed around obstacles, or to suit some other constraint.

The pins can be added when Cornus are created Section 2.1.2.6 or during Section 2.2.8 after clicking on the track. They can be selected and then Left-Drag dragged to alter the curve shape or deleted with Delete.

When a Cornu Track with pins is saved, it is split into two Cornu joined at the pin. If a Cornu that is joined to another Cornu is Modified with Section 2.2.8, the joints are rendered as Pins and the Modify is done for one continuous Cornu.

  1. First, ensure that the Easement type option is set to Cornu - see section 2.10.4
  2. Start the Join Track process by clicking on the Join Track button ().

As you move over tracks a blue roundel will indicate the end that will be chosen with Left-Click.

Left-Click the open endpoint of one of the two tracks being joined. A red dot within a red circle will appear at the end of the join.

Left-Drag the endpoint to where you want it and release the button. The point will only move along the piece of track with the open endpoint (if this track type can be split) as far as the opposite end, or as an extension of that track at the selected end with the same curvature (if this track can be extended). Note that you will be able to fine-tune the end positions later.

Left-Click the endpoint of the other track being joined. Another red dot within a circle will appear at that end of the join.

Left-Drag the endpoint to where you want it and release the button. The second endpoint can only be moved along the second track as far as the other end (if it can be split) or as an extension beyond the end of this track (if it can be extended). The initial curve will be drawn - it will be red if the minimum radius is smaller than the minimum radius option.

You are now in "Select Points" mode.

You can select one end point at a time with Left-Click and move it with Left-Drag. If you drag the end point off the original track it will extend.

You can select a pin by Left-Clicking on it and move it with Left-Drag. Delete will remove the last selected Pin.

You can add a Pin by Left-Clicking on an area of the track with no Pin or end.

Once you are happy, hit Enter or the SpaceBar to finish editing the easement. Or hit Esc to cancel.
If you want to modify the Cornu later (even if it is joined at both ends) see section 2.2.8.8