TIN Builder

Hello everyone!

I continue developing geodetic utilities, and today I present a tool designed for building surface triangulation and contour lines.

What is it for?

I have a colleague who drafts topographic plans in plain AutoCAD without any add-ons… Let’s not discuss whether that is good or bad — there are many people who work this way.

So, my friend keeps Civil 3D installed only to generate a surface and create contours.

This utility was created specifically for people like him.

The tool allows you to:

build a triangulated surface (TIN) from a set of points, blocks, and structural lines,

generate color elevation and slope maps for better visualization,

create contour lines based on the resulting data.

Additionally, the program is capable of processing very large surface datasets even on weak computers… really weak ones :)

This makes it suitable for users who are limited in hardware resources.

The interface is available in both Russian and English.

More detailed information is provided below.

Download links are at the very bottom.

TIN Builder v1.0 — Surface Triangulation, Data Analysis & Report Generation Tool

TIN Builder v1.0 is a professional tool designed for land surveyors, topographic data specialists, civil engineers, and GIS analysts.
The program automates the creation of TIN surfaces (Triangulated Irregular Network) from DXF files, performs data quality analysis, generates elevation and slope maps, constructs contour lines, and produces a comprehensive engineering report.

The application features a fully bilingual interface (Russian / English).

 

Key Features

 

1. DXF Import and Data Analysis

The program automatically analyzes the loaded DXF file and detects all supported data types:

§   AutoCAD POINT entities (XYZ coordinates)

§   Block INSERTs, using the insertion point as an elevation

§   Numeric elevation values extracted from TEXT / MTEXT entities

§   Structural lines: LINE, LWPOLYLINE, POLYLINE (including closed polylines)

The user may choose which data sources to include when building the TIN surface.

 

2. TIN Surface Construction

The TIN surface is created using Delaunay Triangulation with additional engineering filters.

Triangle Filtering Options

The user can specify:

§   Maximum triangle edge length — removes overly stretched triangles

§   Minimum triangle angle — removes narrow “needle-like” triangles

§   Minimum triangle area — removes degenerate or tiny triangles

These filters ensure a clean, accurate, and engineer-grade surface model.

 

3. Structural Lines (Breaklines)

The program supports breaklines—critical structural lines representing real-world features such as berms, slope toes/crests, edges of roads, ditch lines, etc.

Structural lines:

§   are converted into line segments,

§   are checked for intersections with triangles,

§   force the removal and reconstruction of triangles that violate breakline geometry.

As a result, the final TIN surface correctly preserves the true terrain structure.

 

4. Outlier Detection

The program automatically identifies anomalous elevation points — those that deviate sharply from surrounding data due to measurement errors or manual entry mistakes.

The detection algorithm uses:

§   a search radius for neighboring points

§   a height deviation threshold (|dZ|)

Detected outlier points:

§   are marked with red circles in the DXF output,

§   are included in the engineering report,

§   appear highlighted on the PNG elevation and slope maps.

This helps quickly locate problematic measurements and ensures data quality.

 

5. PNG Map Generation

TIN Builder generates two high-quality visualization maps:

Elevation Map

§   color-coded from blue (low elevation) to red (high elevation),

§   shows the complete surface,

§   leaves empty areas outside the TIN boundary.

Slope Map

§   slope values are calculated over a regular grid,

§   colors represent slope steepness,

§   outliers are also marked on the map.

 

6. Contour Lines

The program can generate contour lines based on the constructed TIN:

§   arbitrary contour interval (e.g., 0.5 m or 1 ft),

§   optional major contours (every N-th line),

§   up to 3 levels of spline smoothing,

§   export to DXF separated into layers:

Layer

Content

TIN_TRIANGLES

Surface triangles (3DFACE)

TIN_OUTLIERS

Outlier points

TIN_CONTOUR_MINOR

Minor contours

TIN_CONTOUR_MAJOR

Major (thickened) contours

Contours are not generated in regions without triangles, since such areas are automatically removed from the grid.

 

7. Engineering Report (Report.txt)

A complete text report is generated, including:

§   TIN construction parameters

§   source data statistics

§   elevation range

§   triangle counts (before/after filtering)

§   outlier detection parameters

§   list of all detected outliers

§   slope statistics

§   contour parameters

§   description of created layers

§   references to generated files (DXF, PNG, Report)

The report is available in Russian or English, depending on the selected interface language.

 

8. User Interface

TIN Builder features a modern engineering-style UI:

Interface Characteristics

§   Instant language switching (RU/EN)

§   Dark theme with accent technical colors

§   Grouped parameter sections:

§      data sources

§      triangulation

§      outlier detection

§      contours

§   Log panel with detailed execution messages

§   DXF selection through a native Windows dialog

§   Built-in Help (Manual) and About sections

 

9. Use Cases

TIN Builder is suitable for:

§   surveying and geomatics companies

§   road and infrastructure designers

§   terrain model specialists

§   GIS engineers

§   UAV and LiDAR topographic processing workflows (after DXF export)

§   preliminary engineering calculations

§   field data quality control

 

10. Program Advantages

§   Fully standalone — does not require Civil 3D or other heavy CAD packages

§   Accepts any DXF file, including exports from field controllers

§   True engineering-grade TIN filtering

§   Correct breakline enforcement (no surface distortion)

§   Integrated bilingual help

§   Intuitive interface (no console commands required)

§   Automatic professional report

§   High-quality PNG visualizations

Download: https://drive.google.com/file/d/1IzYEdbxCLWcEP4_n5ea6st91E_C0K83n/view?usp=sharing

Test data: https://drive.google.com/drive/folders/1EG9pijK5R0ST3NPOoMVIpub7Xv85QCZj?usp=sharing

 

If you enjoyed this program and would like to support the author, you can do so here:

https://ko-fi.com/anton57101