This question came in over the weekend, and I thought it was worth capturing in video form. Customer had a plan where they have the start and end coordinate of an arc of known radius (633’) but no start or end bearing and no PI information.
So in the following videos I show the methods that you can use to create the arc and then how to create the alignment from the arc as a first process, and then also a second video that shows how to compute the information required to enter an alignment using a PI based or Geometry based input.
On question that got asked was why when I create an Arc does it always draw it anticlockwise and in the wrong order compared to the way that you key it in. The answer here is that in CAD / AutoCAD an Arc object is always entered in an anticlockwise direction, and the CAD Polyline, CAD Arc and CAD Line objects of TBC were built to mimic AutoCAD objects. The Alignment and Linestring objects in TBC are its native objects and are not hampered by age old CAD geometry types. So when we create the Arc object it is created as a primitive CAD object, I then edit it or convert it to an Alignment or Linestring that is a smarter object in TBC. Once converted I can then reverse its direction and assign it properties like Stationing etc…
Video 1 - Creating the CAD Arc and Converting it into an Alignment
Video 2 - Creating the tangent geometry and the PI reference frame for the arc and entering the data as a PI Based Alignment or Geometry Alignment.
Image of PDF Page
