Create 3D - Line

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.

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.

Run the function from the following location:

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

MOUS_ICO Menu: Road > Elevation Tools > 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):

MOUS_ICO Toolbar: Novapoint Base:  object_menu

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:

1. Exit the function Create 3D - Line.

2. Run the function Convert Arc to Straight Lines to add break points for the source object.

   • Alternatively, run the function convert_arc_to_straight_lines (has additional features for elevation, CAD properties, etc.) to add break points.

3. Run the function Create 3D - Line to define the elevation - see Elevations from NYLP, Point Elevation <, and Heights below.

4. Save the data - see Save (TITUT) below.

5. Present the 3D line using the option 3D - Draw.

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.

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

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

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

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

• However, 5.0 m is too small for sub-division of edge lines, traffic islands, traffic intersections, etc. 0.5 m is perhaps a better value in these cases.

Accuracy

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

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, accuracy is increased and arcs/circles/spirals are subdivided into more 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 10.0 m is converted to straight lines:

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.

KOF File

KOF is a Norwegian coordinate file format.

• KOF format represents X, Y, and Z coordinates at a regular interval along with 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.

• The first three rows are headings and information rows.

• The second column represents chainage.

• The third column is for feature code.

• The fourth column is for Y - coordinate (Northing).

• The fifth column is for X - coordinate (Easting).

• The sixth column is for Z - coordinate (Elevations).

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. Desired value other than zero can also be used.

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.

• Assign a group using the button 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>:

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.

Object Menu (NCO)

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).

Next topic: Create Parallel 3D - Lines

• 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 the same to the 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 above.

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

• For alignment objects, use the function Export to File of the module alignment_design.

• For 3D lines, use the function Export of the module Novapoint Base.

  • The essential condition, in this case, is that the 3D line has to be saved to the database (Digital Terrain Model/DTM).

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 an 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:

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:

• To assign/modify elevations for the key points.

• 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 at the field Height at this end point 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.

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 NYLP File.