Tin triangulating incorrectly - corridor modeler

Question

I am working on our final model for the dtm, finished grade tin, and top of dirt tin in Geopak SS2 Roadway Designer. I recently had to create additional templates to aid in the top of dirt surface creation. In doing so, somehow now my top of surface tin is not triangulating correctly for the sidewalks in a few templates. I can&rsquo;t seem to figure out what is causing this problem. This corridor now has over 20 templates and this is occurring in 7 of them. My recent changes to the corridor were primarily new templates to remove parametric constraints that made components go to zero (since the top of dirt alternate surface triangulated to those zero width components) and also merging points that were sitting on top of each other. 
 
 Anyone have any ideas what could be wrong?

Running GEOPAK V8i (Selectseries 2) 08.11.07.615, Microstation V8i

The Zen Dude · Answer

Emily, as Beebe Ray mentioned, this is a tricky one to diagnose without really looking at how the modeling is set up with all of its controls; it's not directly evident in the ITL alone. I attempted to download the files you posted but was unsuccessful. But I will say that whenever I've seen this in the past it's because of duplicate breaklines (horizontally) each with different elevations. In cases like this, the triangulation (at least from an InRoads perspective) will remove 'certain' overlapping (horizontally duplicate) breaklines. The result is an up and down jump between the breaklines that are retained resulting in triangulation that looks like you show. In InRoads I would look at the DTM and review the Features, Crossing Breaklines, and Triangulation report. This review would at least identify the problem in the resulting surface. And then it could be traced back to the Roadway Designer and Templates to find the source of the problem.

Derek Schmidt · Answer

I've had the same problem in the past, though it no longer occurs with my current workflow. One piece of guidance I might have, though, is that from more recent work in the ITL file, I've noticed an attribute applied to points within the XML of the ITL file:

For example:

<Point name="inside31" featureName="" style="Znull" includeInSubgrade="false" subgradeName="" x="-0.766044443" y="0.357212390" isPartOfBackbone="true" superType="0" superTransitionType="0" superNonLinearLength="0.000000000" transitionX="0.000000000" transitionY="0.000000000" XByExternalControl="false" YByExternalControl="false" ControlledByParametric="0" isTopPoint="false">

I believe the key part here is:

<Point name="inside31" isTopPoint="false">

I haven't experimented with this before, but from what I can tell, this isTopPoint toggle appears nowhere in our template editor tools. And this toggle may be the issue at hand. You might want to open your ITL, locate some points that you know shouldn't be top points, especially ones that are picked up properly, and then locate some points that you know are causing trouble. See if you notice a pattern.

I don't know a particularly good XML editor, which would probably be of great help, but I use Notepad++ effectively. Just don't expect to get good use out of the Notepad that comes with Windows.