Why does the command fail if the segment does not contain a grade line?

Summary

Several commands of the longitudinal profile module (drawing the compound profile, extracting a 3D polyline) expect to find a grade line file inside the segment. If the segment only contains the horizontal alignment and the longitudinal profile of the terrain, the command fails —either with an execution error or without generating anything— because there is no grade line to process. This article explains how to recognise these cases and how to solve them.

Applies to

• MDT — applies to MDT 9, MDT 25 and MDT 26 (error message MDT25_LONG_DIBUJASEG in MDT 25; drawing the compound profile of a segment without a grade line did work in MDT 9 and earlier versions).

• Longitudinal profiles module

Symptoms

• When running Draw Compound Profile, an execution failure error naming MDT25_LONG_DIBUJASEG appears as soon as the segment is selected, without even showing a dialog box.

• The option to extract a 3D polyline from a segment does not generate anything.

Cause

The command being used expects the segment to contain a grade line, while the segment only holds the horizontal alignment (.eje) and the terrain longitudinal profile (.lon). Without a grade line in the segment, the compound profile cannot be drawn and the 3D polyline cannot be extracted.

Solution

Case: execution failure MDT25_LONG_DIBUJASEG when drawing the compound profile

The Draw Compound Profile command expects the selected segment to contain a grade line file. If the segment consists only of the horizontal alignment (.eje) and the longitudinal profile (.lon), selecting it triggers the error, with no chance to interact with any dialog box.

1. Run Draw Simple Profile instead, selecting either the longitudinal profile or the segment file.

2. If the file selection dialog does not list the segment, change the file filter extension so that you can select it.

3. If the longitudinal profile was generated with singular points, the simple profile already includes that information.

Case: extracting a 3D polyline from a segment generates nothing

The 3D polyline is extracted from the grade line of the segment. If the segment only contains the horizontal alignment and the longitudinal profile, the command creates nothing.

1. If the longitudinal profile is the one meant to act as the grade line, run Copy Terrain to Grade Line.

2. Include the resulting grade line in the segment.

3. Run the option to convert to a 3D polyline again.

If the problem persists

• Use the segments command to check which files the segment actually contains (horizontal alignment, longitudinal profile, grade line): most of these failures come down to the missing grade line.

• Contact APLITOP technical support, indicating your MDT version, the exact command you are running and a screenshot of the error.

Category: Longitudinal profiles · Level: Intermediate