# Create 3D - Line

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.

## Procedure

Run the function from the following location:

MOUS_ICO Toolbar: Road > Toolbars > Elevation Tools:Â  Create 3D - Line

Command prompts for:

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

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

Use the Undo option to remove the previous selection.

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

Command prompts for:

Select an entity:

Pick the source entity.

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 into 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 very well.

In general, the function reads the break points of 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 as arcs are having only two break points. Hence it is essential to convert the source object into lines only (to have more break points).

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) with 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 the line elements of the source object, thereby assigning elevations at more points rather than just at the start and end points of line elements.

These settings are defined in the dialog Lines Only, which pops 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.

There is no rule so that an appropriate value can be used, 5.0m is perhaps sufficient for long lines.

### Accuracy

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

Table 1: Degree of 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 10.0 m is converted to straight lines:

Table 2: Deviation from the source when a circle with a radius of 10.0m is converted to straight lines

Figure 1: Example convert arc to straight lines

Table 3: Example TIT Format

### LIN File

Use this option to save the data in LIN format.

Table 4: Example LIN Format

### KOF File

KOF is a Norwegian coordinate file format.

The dialog box Polyline to a KOF file will pop.

### Read elevation from NYLP file

Select the NYLP file to link the vertical geometry (*.NYP file) to the data being saved as a KOF file.

### Feature Code

Define the feature code for the data being saved.

### Start/End Chainage

Limit the section of the data being saved using these fields.

### Interval

Define the interval for coordinate points.

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.

### End Points

Mark the check box to include the coordinates of end points of the elements in addition to the coordinates as per the interval.

### KOF File

Define the location and name for the KOF file.

Table 5: 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. Desired value other than zero can also be used.

Table 6: Example NYLP Format

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 â€“ 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>:

Answering Yes (default) erases the lines loaded to the function Create 3D line and answering No retains the lines loaded to the function Create 3D line.

To edit a 3D line created by this function and for its associated functions, run the function object_menu.

## Related Topics

Convert Arc to Straight Lines (alternative for Lines Only).

## Elevations from NYLP

Use this option to read the elevations from an NYLP (ASCII) file and assign the same to the 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:

Pick the point to assign elevation.

Select text with elevation:

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 a suffix. The program does not read other formats of text.

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

Height <0.00>:

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

Pick a point for elevation:

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.

### 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: