When I import a DTM file that has several unconnected ditches in the same terrain model extra triangles are created to connect the areas. This gives incorrect volumes in quantity calculations.
The same happens when I try to create the terrain model from mesh elements. The best solution I can find is to use "Create terrain model from design meshes" this retains the element's boundaries but instead produces a terrain model for every single ditch area. This can end in 20 - 30 extra files.
Is it possible to make 1 terrain model that will cover all these ditch areas??
Openroads 2021 R1
You can have multiple terrain models in a single DGN. In the past, you needed a DTM file for every separate surface. Now, if you have separate but related surfaces, they can all be stored in a single DGN file. But to prevent the connecting triangles, they must be separate terrain elements. This was sort of true in the days of DTM files.
You might be able to get it to not draw the long triangles, but one DTM could only have one exterior boundary and often, that was the only way to prevent other edge triangles from being formed.
Charles (Chuck) Rheault CADD Manager
MDOT State Highway Administration
Answer Verified By: Pete Otiv
Thanks for the answer, I'll just have to make a load of terrain models then.
Have you considered creating a complex terrain model that incorporates all the small terrain models so you only have one terrain model? You may have to add interior boundaries to prevent proposed triangles in unwanted areas. An exterior boundary may also be needed to achieve the desired results.
hth.
pevans
I had a go and it didn't really work, plus it is way too complicated and processor heavy anyway. Thanks for the help but I think I'll be reinstalling SS2 until a better solution comes along.
Might not be applicable to your specific case but if you wanted to join two disconnected terrain models you could create a dummy close element joining the two and defined as a void. It might get complicated depending how complex the edge conditions of your terrain models are.
If creating a complex terrain as suggested by others is too processor heavy, you could look at working with several LandXML exports of separate terrains and only update on demand? Lastly, you could also combine multiple LandXML's into a single LandXML and import as a single terrain model and it should honour the gaps between terrains.