TIN command

Creates a new TIN Surface from selected source data.

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Description

A TIN Surface is a three-dimensional geometric representation of a terrain or a civil feature, which also includes its representation with triangles, contours, slopes, spot elevations, and elevation ranges.

The algorithm connects the nearest lying points into triangles that form a Triangular Irregular Network (TIN), using the Delaunay triangulation method.

You can affect the way points are connected by adding boundaries and breaklines to the TIN Surface. Triangles always follow specified boundaries and breaklines and never intersect them. You can also edit the TIN Surface with other options available in the TINEDIT command.

A TIN Surface is dynamically linked to most of its input data, such as Point files, Point Groups, Point Clouds, Civil points and Contours. Point files and point clouds are usually no longer modified by users after a TIN Surface has been created from them. Therefore, in the next step after the creation of the TIN surface, a snapshot of the TIN surface is automatically created. This breaks the link to the input data. You can remove the Create snapshot definition in the Civil Explorer to re-establish the dynamic link.

Dynamic link is not supported for CAD elements and 3D faces. Changing these types of input data does not affect the triangulation of the TIN surface.

Method

The following type of source data can be used to create a TIN Surface with the TIN command:

  • CAD elements (points and linear entities) and Civil points
  • Point files
  • Civil points specified in the drawing
  • 3D Face elements
  • Point Clouds
  • Point Groups
  • Contours

Launch the TIN command from the Ribbon, Civil Toolbar, Command line, or from the Civil Explorer panel. Select the source data type and specify the input elements. New data is added to the TIN Surface as a new Definition.

Options within the command

Select entities to create TIN surface
Creates a TIN Surface from selected drawing entities/objects.

When creating TIN Surface from linear objects, the Command line prompts you to choose an option how to apply linear entities: as Points, Edges or Breaklines.

If you select to apply linear entities as breaklines, a new Add breaklines definition is added to the TIN Surface. In this case, the Command line prompts you to specify the weeding and supplementing parameters. Some other parameters, such as the Breakline type, the Crossing elevation and the Mid-ordinate distance, are pre-defined. They can be easily modified in the Add breaklines definition dialog box from the Civil Explorer panel.

Otherwise, the selected linear objects are added to the Add drawing objects definition as TIN Surface points or edges.

Import from file
Creates a TIN surface from selected point files. Selecting this option in the Command line opens the Create Surface From Point File dialog box, where you can select point files and appropriate point file formats. If the predefined point file formats are not suitable, you can define your own format with a custom file extension, delimiter, comment tag and columns. When a file is selected, the command offers the option to simplify and densify points used to create the TIN Surface.
Note: For more information about TIN Definitions see TIN Definitions in the TIN command and Civil Explorer panel articles.
place Points
Creates a TIN surface from specified locations and elevations of the TIN points.
Pick point
Allows you to specify the location of the TIN point.
Enter elevation
Allows you to enter the elevation of the TIN point.
create from Faces
Creates a TIN Surface from the selected 3D Face elements.

If you select the Apply 3D Faces as edges and visibility option, the vertices and edges of 3D Face elements are taken for the triangulation. Thus, TIN Surface triangles overlap with the 3D faces. The shape of the outer envelope of the 3D face elements is also preserved. Otherwise, only the vertices of the 3D Face elements are taken for triangulation. This means that the TIN Surface does not always overlap with 3D Face elements. Also, additional triangles are created on the outer envelope of the 3D Face elements so that the outer boundary of the TIN Surface has a convex shape.

create from point Cloud
Creates a TIN Surface from a selected Point Cloud.
Simplify TIN surface?
Yes: simplifies source points used to create TIN Surface based on the specified simplification parameters, described below.
  • Radius for simplification step: the cell size, that forms virtual grid spread over the entire set of source points. Within each cell, all points with an elevation difference greater than the specified maximum, are eliminated / simplified.
  • Elevation difference: maximum elevation difference between adjacent points on the TIN Surface. All points with a higher elevation difference are excluded from the TIN Surface.
No:: a TIN Surface is created from all points in the input point file or in Point Cloud.
Note: After the first iteration of the simplification, a report on the command line displays, stating the number of points before simplification, the number of removed points and the number of points after simplification.

In the next step, you can choose between the options Simplify again or Create TIN Surface.

Create TIN surface
Creates the TIN Surface.
Simplify again
Simplifies the TIN Surface with new proposed simplification parameters so that more points are removed than in the first iteration.
Densify TIN surface
Yes: after the TIN Surface is simplified, the maximum allowed elevation difference between the simplified TIN Surface and the excluded input points on a specified area in a TIN Surface is specified. All input points with a greater elevation difference than specified are added back to the simplified TIN Surface.

No: the TIN surface is created according to the specified parameters for simplification parameters.

Select polygons
Densifies the TIN Surface within the selected polygon.
Draw polygon
Densifies the TIN Surface within the drawn polygon.
Enter for entire TIN surface
Densifies the entire TIN Surface.
Note: For more information on the simplify and densify process, see the TIN Simplify and TIN Densify articles.
create from point Groups
Creates a TIN Surface from a selected Point Groups.
Note: By default, Civil points are placed in the “_All points” Point Group. Use the CIVILPOINTGROUP command to create a new Point Group.
The Select Point Groups dialog box opens:
  1. Select box
  2. Point group
  3. Number of points
Select box
Allows you to select or deselect a point group to be included.
Point group
Lists all available point groups.
Number of points
Displays the number of points in the point group.
create from cOntours
Creates a TIN Surface from selected line elements.
Use weeding factors

Yes: existing contour vertices are not used to create a TIN Surface, if the distance and angle between them is less than the specified weeding parameters.

No: all the vertices of source line elements are used to create the TIN Surface from the Contours.

Use supplementing factors

Yes: additional vertices are added to contours, if the distance between vertices on the contour is greater than the specified supplementing distance.

No: all the vertices of source line elements are used to create the TIN Surface from the Contours.

create from Mesh
Creates a TIN Surface from Mesh or Polyface Mesh entities.
cLip polygon
Adds a Clip Boundary to the TIN Surface.
create from point Groups
Creates a TIN Surface from a selected Point Groups.
create from cOntours
Creates a TIN Surface from selected line elements.
Use weeding factors

Yes: existing contour vertices are not used to create a TIN Surface, if the distance and angle between them is less than the specified weeding parameters.

No: all the vertices of source line elements are used to create the TIN Surface from the Contours.

Use supplementing factors

Yes: additional vertices are added to contours, if the distance between vertices on the contour is greater than the specified supplementing distance.

No: all the vertices of source line elements are used to create the TIN Surface from the Contours.

cLip polygon
Adds a Clip Boundary to the TIN Surface.
Note: For more information about clip polygon see TIN Definitions in TINEDIT command article.