PGRD

Create COGO points along objects, straight-graded between spot elevations.

Originally written with polylines in mind, this routine works well on any linear object, such as a line, arc, or even a spline.

Usage:

Start the PGRD command and follow the prompts. The PGRD command honors the current Point Settings. In other words, you may specify a default description in the Point Settings, or you may configure the Point Settings so that the PGRD command asks you for a description for every point.

The PGRD command starts at the end closest to your selection, and left and right are determined accordingly. A negative offset is to the left, and a positive offset is to the right. It does not matter which direction the object was drawn in; the starting point is always the end closest to your selection point. Use the "Jump" option to skip a segment.

Example 1:

Assume the following diagram illustrates an edge of pavement. The edge of pavement is a single polyline. We wish to place graded offset points around the edge of pavement. Assume we have the two spot elevations shown.

We run the PGRD command, and configure the dialog box as follows:

The next prompt asks for either the end elevation, or the location of the next grade break. For this example, we just enter 120.00 as the end elevation. The start elevation is the "Current Elevation" in the dialog box. We also enter "Yes" when it asks if we want to set the endpoint. The result is as follows:

The maximum distance between points was specified as 60.00 feet in the dialog box. Note, however, that we checked "Set Extra MPs" in the dialog box, as well. This forces the PGRD routine to set a point at the midpoint of the arc. In this case, the setting caused Points 503 and 514 to be set, even though they are less than 60.00 feet apart. In other cases, this option might cause, for example, five points to be set around a curve instead of four, so that the midpoint gets set.

When the routine hits an arc segment, or if you run the routine on an arc, the PGRD command will ask you if you want to set a point at the radius point. You can hit ESC to skip the point, or hit return to set the point with the proposed description, or type a description and hit return. The proposed description is created by taking the radius of the arc and appending the "Rad Pt Suffix" from the dialog box.

If the radius of the arc segment is longer than the "Max Rad for RP" value specified in the dialog box, then PGRD will automatically skip the radius point. In this example, the the "Max Rad for RP" is 30.00 feet. The radius of the arcs from Points 509 to 511 and from Points 516 to 518 is 40.00 feet, so PGRD will not ask you if you want to set a radius point for these arcs. It simply skips them, and only sets the offset points.

If offset points are being placed along the inside of an arc and the radius of the arc is less than the "Min Rad for Pts" in the dialog box, then no offset points will be set along the arc. In this example, the "Min Rad for Pts" is 5.0 feet. Therefore, PGRD sets Point 505, but no other points around that curve. However, the offset points are on the outside of the other arc with a 1.5 foot radius, so points are set around it. The "Set Extra MPs" flag is also set, so the midpoint is set. The result is PGRD creates Points 502, 503, and 504.

Example 2:

This is the same as Example 1, except this time assume we have a grade break at the indicated point:

This time we will run the PGRD command with the same basic settings, but we will pick the other end of the polyline as the start point. This means that the offsets will be placed on the opposite side.

We must also enter the grade break. We are starting at the end on the right side, so in the dialog box, we make sure the "Current Elevation" is set to 120.00. Then, at the next prompt, we select the grade break, and key in 90.00. Note that it is not necessary to pick exactly on the line; you may pick off to the side, and the selection will "snap to" the line. The routine now sets the points from the beginning to the grade break. At that point, we enter 100.00 as the end elevation, and set the remaining points. The result is as follows: