TIN Error

Hello everyone,

I am attempting to troubleshoot an issue I have been having when creating a TIN file on some of my projects. After I have classified the terrain using the Terrain Filter, and have gone through verifying the areas i want to have incorporated in the TIN file, I create the Grid of Points at a 0.5m spacing. I generally from here will run a smart TIN with terrain breaklines turned on. Some of my sites however, have large tree’d areas that I normally remove and proceed, almost all of them though have water retention ponds that I also clear from inconsistencies in the points and generally trace around the waters edge removing everything from the center. The problem I am running into though, in these areas where I have removed no-terrain points I generally get a large flat surface across connecting two areas together. One of my sites is separated by a Large forested valley area through the center and 5 ponds around the site, when a TIN is generated all become flat surfaces.

Is there any way to tell Survey to leave these areas out when generating a surface?

I have attached 2 images showing what I mean.

Hi @andrewross,

Thank you for your message.

Please try to generate the TIN using the Smart edges.

(this is an old screenshot, now the processing sidebar is on the left, but the idea remains the same)

This involves extra post-processing by trying to build a border that fits more closely the shape of the grid points (a concave shape), and remove all the TIN triangles that are outside of this border.

You can find more information here:

Please let me know how it goes.

Hey Daniele,

I have tried this multiple times without any luck in the TIN construction not including areas that have no points. I am currently working on a project that is separated by a large vegetated area that I am not to include. When processing the TIN surface, the entire gap between the two working areas is joined, This is the same with the small changes in the boarder around the project.

I have tried creating boarders with Terrain lines, polylines, polygons, markers all with no result. I have spent countless hours cleaning up the edges as you’ve suggested but still no result. I always process with smart edges and spend a significant amount of time cleaning them up before processing the Grid of Points and TIN but it very rarely works out as intended.

I don’t know if there has been an update to correct these things since I have last updated, (1.54.2 is my current version) but I would like to have a solution for this that can be done within Survey rather then outside software.

Hi @andrewross

To understand correctly, you have two distinct areas in your project and you don’t want the two TINs to be connected. Did I understand this correctly?

Did the Smart Edges helped a bit in the project yo shared some posts above?


Hey Daniele,

Yes you did understand correctly. I was able to bypass this by simply removing one of the areas, and processing a Grid of Points, then a TIN and exporting that followed by changing the name. I would then have to undo those steps and repeat them for the other side of the site which would recreate the second TIN file. I’m hoping this will work for my client.

Unfortunately it did not for the previous project either. This creates an issue as it provides a surface for areas that do not exist as well as an output file that is larger then it needs to be. If there is a way to edit the TIN file, that would be great, but as far as I am aware, the only way to do that would be in another CAD based software.

1 Like

Hi @andrewross,

Thank you for confirming this.

I passed all the information to the product team for evaluation. Even though we cannot guarantee that a solution will be implemented, I can assure you that every piece of feedback is internally evaluated at Pix4D.