This command creates Carlson points using a section (.SCT) file to
define the point
elevations. The x,y position of the points are calculated based on the
station and offset along a
centerline polyline. These points are stored in the current coordinate
(.CRD) file and can also be plotted
in the drawing. Points can be created at each station in the section
file or at a set station interval.
The range of stations to process can also be set. The Description Match
field can be used to filter
the offsets and only create points with matching descriptions (e.g.
only
"EOP" offsets). The
Create points at fixed offsets option can be used to make points at
user-specified offset distances.
The program will interpolate the elevations for these points by
interpolating from the
neighboring offsets. The is both a Centerline by Polyline or by CL File
option. The CL File option will prompt for an existing centerline (.CL)
file. The Reduce Points option will skip creating points for the same
offset between
stations if the x,y position and elevation change is less than the
offset tolerance. Essentially, when a
series of offsets are on a straight line (no vertical and no horizontal
curve) then only the starting and
ending points are needed and all the intermediate points can be
skipped. For example, the Reduce
Points routine will look at the left side EOP offset points at stations
1+00, 1+05 and 1+10 and if these
three points make a straight line then the point for station 1+05 can
be reduced. The Offset Distance
is the tolerance that Reduce Points using for testing whether the
middle point (offset point at
station 1+05) can be reduced. The distance for the middle point is
calculated as the perpendicular
distance from the middle point to the line between the two end points.
Both the horizontal and
vertical distances are checked.
Sections to Points Settings dialog
Coordinate File to Process Choose
a .CRD or other coordinate file to add the points to.
This prompt only occurs if no coordinate file
is current.
Choose SCT file to read pick
the cross section file
Range of stations: 3.34 to 750.00
Enter the starting station to process <3.34>: press Enter
Enter the ending station to process <750.00>:
press Enter
Select centerline polyline: pick the polyline that defines
the stations
Type of centerline [<ROadway>/RAilroad]? RO
Enter the centerline starting station
<0.0>: press Enter
Created 65 points.
Pulldown Menu Location: Sections >
Section Utilities
Keyboard Command: sctopt
Prerequisite: A .sct file and polyline centerline
File Name: \lsp\plinsct.lsp