TL Grade Tree

TL Grade Tree

Win64, English

Todor Latev
Recursively generates all possible lines along an Autodesk® Civil 3D® surface from a given start point having a specified grade.

General Usage Instructions

Click on the TL Grade Tree icon in the Add-ins tab or type TLGradeTree at the command line in Civil 3D.

Select a Civil 3D tin surface and pick a start point. If only one tin surface exists in the current drawing the program may automatically select it and not ask for a surface. Enter a grade in %. Positive grades mean going uphill and negative grades mean going downhill. Grades of 0% (contour lines) are not supported.

Watch the grade tree generation on the screen. This process may take a while but you should still be able to zoom/pan around. Abort the command at any time by pressing the Escape key or press Space for current info.

Once the command is complete you may use the standard Autodesk® AutoCAD®_join command to merge individual branch lines into a 3D polyline, which in turn can be used to build a feature line or an alignment and profile.

Command settings:

  • Recursion depth limit: integer, range 1-30000, default 2000. Max number of tin triangles to process away from the starting point.
  • Suppress max recursion info messages: boolean, default: false. When a triangle is reached at the max recursion depth distance from the starting point print some information before moving on to the other branches
  • Mode: Bifurcate/branch at every point/triangle, boolean, default false. Uses a simplified algorithm for generating the grade tree. Grade points are computed for every intersection point from the previous iteration, regardless of whether the triangle has been previously traversed. This is a more vigorous mathematical approach to solving the problem, however it tends to produce excessive number of lines and progresses very slowly. Use this setting for surfaces with relatively large triangles where all possible grade branches need to be visualized 


Ribbon/Toolbar Icon Command Command Description


Generates the grade tree from a specified start point


Activates the App with the Autodesk App Store. An active internet connection is required. Once activated the app can be used offline. This command is not available in the ribbon and needs to be manually typed in at the AutoCAD command prompt


The installer that ran when you downloaded this app/plug-in from Autodesk App Store will start installing the app/plug-in. OR, simply double-click the downloaded installer to install the app/plugin.

You may need to restart the Autodesk product to activate the app/plug-in.

To uninstall this plug-in, exit the Autodesk product if you are currently running it, simply rerun the installer, and select the "Uninstall" button. OR, click Control Panel > Programs > Programs and Features (Windows 7/8.1/10/11) and uninstall as you would any other application from your system.

Once the installation is complete, start Civil 3D and login with your Autodesk user id and password. Run the TLGradeTreeActivate command to activate the app with the App Store. Once activated the app can be used offline.

Additional Information

Max recursion depth limit is 30000.

Max grade is 1000000%.

When a grade tree generation is in progress user may press Escape key to abort the command or Space for current info.

Known Issues

  • Currently grid surfaces are not supported. 
  • If mode is set to "Bifurcate at every tin triangle" with a high setting for the recursion depth a complex surface may trigger an exponential line generation causing Civil 3D to consume all available RAM memory and eventually crash. Save your work before issuing the command and/or press the Escape key to abort a command already in progress.
  • Grades of 0 (contour lines) are not supported.


Author/Company Information

Todor Latev

Support Information

For questions/comments/suggestions/bug reports etc. please send an email to

Version History

Version Number Version Description


Added 2024 support (No change in version number).


Original release
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