# 3D - Lines

Use this function for the following:

The resulting 3D polyline consists of line elements only. All the lines/arcs/circles/spirals of the source object will be converted into a series of straight lines before assigning elevations.

## Working procedure

This function is also available in Road, Waterway, and Civil Construction.

Find it here:

MOUS_ICO Toolbar: Terrain > Toolbars > Terrain Design: 3D - Lines

MOUS_ICO Menu: Terrain > Terrain Design > 3D - Lines

Command prompts for:

Pick a line, arc, polyline: <Enter> = Read from file OK.

MOUS_ICO Pick the source object(s) from the current drawing or hit Enter to read an ASCII file

KEYB_ICO Use the Undo option to remove the previous selection

Tip: Shortcut to this function in case the source object is a CAD entity (2D or 3D):

Command prompts for:

Select an Entity:

MOUS_ICO Pick the source entity

MOUS_ICO Select the flyout menu option 'Draw as 3D - Line'

## Lines only

Use this option to convert the source object into a series of straight lines.

Converting a source object composed of arcs/spirals to a 3D polyline requires the arcs/spirals to be replaced by a series of straight lines (more break points). This adds more break points and the converted 3D polyline follows the curvature of the arcs/spirals of the source object.

In general, the function reads the break points of the source object, assigns elevations, and joins them with lines (3D). In this process, the curvature of the arcs/spirals in the source object will be lost. The converted lines from the arcs/spirals have two break points for each line. Further in this process, the line elements of the source object will also be converted into a series of straight lines to have more break points.

Tip: If the line elements of the source object are to be unaltered in view of break points, do the following:

The accuracy (curvature) of the source object in converting it into straight lines can be controlled with the parameter 'Accuracy'. The length of sub-divided lines is determined by the radius/parameter (spiral) and the accuracy.

This option can also be used to add more break points on line elements of the source object, thereby having elevations assigned at more points, rather than just at start and end points of line elements.

These setting are defined in the dialog 'Lines Only', which pop up with this button.

### Maximum length of each line

The length of the straight lines resulting from the conversion to 3D polyline is controlled with this option.

### Accuracy

The degree of accuracy determines the number of elemental straight lines, the source object is to be sub-divided.

0.1 Very low accuracy

0.5 Half accuracy

1.0 Default

2.0 Double accuracy

3.0 Very High accuracy

In most cases, an accuracy of 1.00 is more than sufficient.

Any value from 0.1 to 3.0 or higher can be used. The accuracy and the deviation from the source are mentioned below when a circle with a radius of 10.0m is converted to straight lines:

### Accuracy Maximum Deviation between Radius and Line Segment Line Segment Length

0.5 12.4mm 0.997m

1.0 3.10mm 0.499m

2.0 0.78mm 0.249m

## Elevations from NYLP

Use this option to read the elevations from an NYLP (ASCII) file and assign it to 3D Polyline.

NYLP files can be automatically generated from alignment objects and existing 3D lines (CAD).

## Point elevation <

Use this option to assign the elevations from the desired points (need not be a break point) of the source object.

When this option is availed, command prompts for:

Pick a point for elevation:

MOUS_ICO Pick the point to assign elevation

Select text with elevation:

MOUS_ICO Pick the text entity that has the elevation value. The program reads if the text is in the form +/- elevation value, e.g., 565.125, -515.325, +418.290, etc. The text can have suffix. The program does not read other formats of text.

MOUS_ICO If text is not available, hit 'Enter' to key in the elevation value

Height <0.00>:

KEYB_ICO Confirm the elevation value read from the text or key in the elevation value (+/-)

Pick a point for elevation:

MOUS_ICO Pick the next point to assign elevation or exit the command

## Heights

Use this option for the following:

The dialog 'TenTable - Z - Coordinates' will pop up with this option.

### Interpolation

Define the section for interpolation using the fields 'From Point No.' and 'To Point No.' and hit the button 'Interpolate between these Points'

Note: If elevations are defined for 3 or more points, first interpolate the first two key points and then between the next two key points, and so on

## Save (TITUT)

Use this option to save the data (2D or 3D) to ASCII files (*.TIT, *.LIN, *.LI, *.DAT, *.KOF and *.NYL) or to database (Digital Terrain Model/DTM).

The dialog 'Horizontal alignment' will pop up with this button.

### Element Number

Define the element number for the first element of the source object/3D Polyline

### Stationing/Chainage

Define the start chainage value at the field 'Start at Station No.'

### View TenTable

The data can be viewed in 'TenTable Format (*.TIT) (ASCII)' (only horizontal geometry; no elevations) before saving.

Other ASCII formats (INH, LIN, LI, and DAT) can also be viewed using the button 'Select from File' of the dialog 'View Alignment Geometry'.

### TIT File

Use this option to save the data in TIT format.

Notes:

Example - TIT Format

Code Start Northing Start Easting     End Northing End Easting       End Chainage   Blank

### LIN File

Use this option to save the data in LIN format.

Example - LIN Format

### KOF File

KOF is a Norwegian coordinate file format.

The dialog box 'Polyline to a KOF file' will pop.

Tip: To have the KOF file only for the break points, define an interval that is much higher than the length of the data and mark the option 'End Points'

Example - KOF Format

### NYLP File

NYLP format is for vertical geometry (profile) of alignment. If the horizontal geometry is created using a 3D Polyline, vertical geometry (NYLP file) can be created from the 3D Polyline using this option.

The dialog box '3D Polyline to NYLP file' will pop up.

It is usual in profile lines to use a radius equal to zero at start and end points. A desired value other than zero can also be used.

Example - NYLP Format

First Row <Descriptive text>

Second Row <Descriptive text>

Third Row <Descriptive text>

Fourth Row <ASCII file location>

Fifth Row Start Chainage Interval End Chainage

Data Rows Chainage at Angular Point Elevation at Angular Point Radius of the Circular Curve

Use this option to save the data as an object in the database (Digital Terrain Model/DTM). The dialog 'Object Identification' will pop up.

## 3D – Draw

Use this option to present the 3D Polyline on the current drawing

Command prompts for:

Erase old line(s) before drawing the new one? No/<Yes>:

KEYB_ICO Answering 'Yes' (defult) erase the lines loaded to the function 'Create 3D line' and answering 'No' retains the lines loaded to the function 'Create 3D line'.