Flip Edge allows you to flip your triangle edges to better match the terrain between survey points. Flip Edge is a surface item editing tool that appears when you click the Edit Surface button in the TOOLS tab. 


Quick Usage Guide

  1. Select a surface item.
  2. Go to the TOOLS tab.
  3. Click the Edit Surface button and tick the Flip Edge tool under Edit Surface Mode.
  4. Click on the edges of triangles to flip them.
    1. The edges turn red when you hover over them, indicating they are being selected to flip.
  5. Right-click in the Viewport to exit the Edit Surface mode.

Why the Flip Edge Tool is Necessary

When creating a traditional surface, the software cannot know how to form the triangles that best match the terrain. The triangles of the traditionally created TIN do not always match the terrain in a way that would be obvious to the human eye. Virtual Surveyor's Flip Edge tool allows the user to review the surface and flip edges between survey points to better match the TIN to the Elevation Terrain.

When to Use the Flip Edge Tool

  • Flip the edges of triangles where they can better represent the terrain. For example, in the image below, we flip the line shows an inaccurate extension of the terrain at the baseline of the steep slope. 

  • After flipping the edge, you can see it is in line with the baseline of the slope.

Exceptions: When You Cannot Flip an Edge

You may come across a couple of situations where you are not able to flip an edge:

  • If the flip generates overlapping triangles.
  • On the outermost edge of a surface.

Tips and Tricks 

  • If you find yourself needing to flip multiple edges across your created surface, you can try our Auto-Flip Edges function that automatically creates triangles that best match the terrain.
  • In some situations, flipping edges may not add the proper data set to match the underlying terrain; you might be better off by quickly fixing your survey points and regenerating a new surface TIN that more accurately resembles the terrain.