3D - Lines

Use this function for the following:

• to convert a 2D object (source object) into a 3D Polyline with desired elevations at its break points

• to edit the elevations of a 3D Polyline

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.

• The source object can be a line/arc/circle/polyline/spiral/3D Polyline/ASCII (TIT, LIN, INH, LI, and DAT) file.

Working procedure

1. Run the function and select the source object.

2. Split the selected source into a series of straight lines using the option 'Lines only'.

   • This creates more break points (end points where elevations will be assigned).

3. Assign the elevation using any of the following options:

   • Elevation from NYLP: Automatically reads the elevations from an NYL (ASCII) file and assigns the same to the converted 3D Polyline.

   • Point elevation <: Pick a point of the converted 3D Polyline and pick the text entity with elevation value or key in the elevation at the command prompt to assign elevation.

   • Height: Assign elevations for at least two break points and interpolate heights in between them.

4. Save the newly created 3D polyline using the option 'Save (TITUT)'.

5. Draw the newly created 3D polyline using the option '3D - Draw'.

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

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:

1. Run the function 'convert_arc_to_straight_lines' (has additional features for elevation, CAD properties, etc.) to add break points

   • Alternatively, exit the function '3D - lines…'

   • Run the function 'Straight lines only' to add break points for the source object

2. Run the fucntion '3D - Lines…' to define the elevation - see 'Elevations from NYLP', 'Point Elevation <', and 'Heights' below.

3. Save the data - see 'Save (TITUT)' below.

4. Present the 3D - Line using the option '3D - Draw'.

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.

• Define the length (meters) of each elemental straight line

• If the value is 5.0m (default), none of the resulting straight lines will be longer than 5.0m

• This does not mean that all the lines are 5.0m long, but none of the lines will be longer than 5.0m

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.

• If an accuracy of 1.00 does not give sufficient detail, a higher accuracy level can be specified.

• An accuracy of 2.00 subdivides arcs and transition curves into twice as many straight lines as an accuracy of 1.00

• If this value is increased, the accuracy is increased and arcs/circles/spirals are subdivided into a higher number of straight lines with smaller lengths

• Smaller accuracy values give less number of lines and the length of the line element will be more

• Large arcs require greater accuracy than small arcs

• The degree of accuracy must therefore be evaluated from case to case

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

• A = Maximum Deviation between the radius and line segment

• B = Line segment length

• C = Source Object

• D = Resulting 3D Polyline

Elevations from NYLP

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

• The dialog 'Select file' will pop up with this button

  • Browse to the location of the file, select the file, and click the button 'Open'

  • The elevation is read from the selected NYLP file and assigned to the break points of the 3D Polyline

• If more break points are required, use the option 'Lines only'

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.

• Pick the point on the source object

  • Use the snap modes for precise selection

  • The function creates a break point if the selected point is not a break point

• Assign elevation either by picking a text entity that has elevation value or key in the elevation at the command prompt

• Repeat the process for all the key points

• Use 'Heights' for interpolating the elevations in between the assigned key points

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:

1. to assign/modify elevations for the key points

2. to define elevations for all the break points by interpolating the elevations of key points

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

• The upper area lists the details of break points (number, coordinates, and chainage)

• Select a break point for the upper list

• Define the elevations in the 'Height at this end point' field and confirm with the key 'Return'

• Define elevations for all the key points

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).

• Using this option, the source can be directly saved to the database as an alignment object

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.'

• Chainage can be defined either in ascending or descending order

• Mark the desired radio button

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'.

• These ASCII formats are explained in the following sections

TIT File

Use this option to save the data in TIT format.

• Only horizontal geometry will be saved in this format

• Data of each element is represented in two rows in 'TenTable Format'

• The width for the values is 11 characters including the negative sign and the decimal separator

• The width for the code 10 (at the start of each line) is 2 characters

Notes:

• The decimal separator must be Period (Dot) - ensure this in the operating system settings of Windows (Regional and Language Options)

• Related vertical geometry is to be saved in the 'NYLP File'

Example - TIT Format

LIN File

Use this option to save the data in LIN format.

• LIN format is point-based and each point is represented in a single row.

• The first number in the first row represents the total number of rows present in the file.

• The second row represents the details of the first break point.

• The last row represents the data of the last break point.

• Elements are represented in their own rows as Element Number, Start Northing, Start Easting, Start Chainage, Start Radius, Bearing, Parameter (Spiral), End Radius, and Element Length.

Example - LIN Format

KOF File

KOF is a Norwegian coordinate file format.

• KOF format represents X, Y, and Z coordinates at a regular interval along the entity including the end points of each element

• Z-coordinates are automatically included if available in the data

• Alternatively, 'NYLP File' (format for vertical geometry) can be linked to the data

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.

  • By default, the whole data is considered

• 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

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.

• The first three rows are for explanatory text

• The fourth row is for explanatory text on the location and name of the file

• The fifth row is for explanatory text on start chainage, interval, and end chainage.

• The location and name of the file can be defined using the button 'NYLP File' and the same is mapped in the fourth row

  • The same can also be defined in the edit field at this button

• The values are separated by a single space

Radius at End Points

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

Save to Quadri

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

• Define a unique name for the object

• Define feature code using the button 'Feature Code'

  • For further details, refer to 'Feature Code'.

• Assign a group using the button 'Group'

  • For further details, refer to 'Group'.

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'.

Object Menu (NCO)

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

• For further details, refer to '3D Line'

Related Topics

• Convert Arc to Straight Lines (alternative for 'Lines Only')

• Convert Arc to Straight Lines (alternative for 'Lines Only' but have additional features for elevation, CAD properties, etc.)

Next topic: 3D Model - Cross-Section Along Line